Gel test

บทคัดย่อ (ไทย)
การตรวจหาปฏิกิริยาระหว่างแอนติเจนและแอนติบอดีของเม็ดเลือดแดง ใช้หลักการปฏิกิริยาที่จำเพาะแสดงออกให้เห็นในรูปของการจับกลุ่มของเม็ดเลือดแดง (hemagglutination) หรือการแตกของเม็ดเลือดแดง (hemolysis)

โดยทั่วไปใช้วิธีมาตรฐานหลอดทดลองในตัวกลางนำเกลือ ซึ่งวิธีทดสอบดังกล่าวถูกนำมาใช้ในการตรวจหาแอนติเจนของเม็ดเลือดแดง (red cell typing) ตรวจกรองหาแอนติบอดีในซีรัม (antibody screening test) หรือตรวจหาชนิดของแอนติบอดี (antibody identification) ตลอดจนการทดสอบความเข้ากันได้ของเลือดก่อนให้ผู้ป่วย (crossmatching) ปัจจัยสำคัญอันหนึ่งที่มีผลต่อการตรวจหาปฏิกริยาระหว่างแอนติเจนและแอนติบอดีของเม็ดเลือดแดงคือกระบวนการล้างเซลล์ก่อนเติมน้ำยา antihuman globulin serum และเทคนิคการเขย่าเพื่ออ่านผล ซึ่งต้องอาศัยความชำนาญและต้องมีประสบการณ์สูง โดยเฉพาะปฏิกิริยาที่ให้ผลบวกอย่างอ่อน (weak reaction) จึงมีผู้พัฒนาเทคนิค gel test มาใช้ในการตรวจหาปฏิกริยา โดยอาศัยหลักการให้ gel เป็นตัวกรองปฏิกิริยาการจับกลุ่มของเม็ดเลือดแดง โดยหลังจากนำ gel ไปปั่นในความเร็วที่เหมาะสม เม็ดเลือดแดงที่มีการจับกลุ่มจะค้างอยู่ด้านบนของผิว gel ส่วนเม็ดเลือดแดงที่ไม่เกิดการจับกลุ่มจะตกลงที่ก้นหลอด ทำให้ลดข้อผิดพลาดจากเทคนิคการปั่นและเขย่าอ่านผลได้ ในปัจจุบันมีบริษัทที่ผลิต gel test ออกจำหน่ายในท้องตลาดอย่างน้อย 4 บริษัท แต่มีราคาแพงมาก (ประมาณ 20-23 บาท ต่อการทดสอบ) ทำให้เป็นข้อจำกัดอย่างหนึ่งของ gel test ที่จะนำมาใช้ในงานประจำวัน ดังนั้นคณะผู้วิจัยจึงมีความประสงค์ที่จะพัฒนาและผลิต microtube gel test ขึ้นใช้ในห้องปฏิบัติการคลังเลือด โดยใช้อุปกรณ์พื้นฐานที่มีใช้ในห้องปฏิบัติการ และปรับปรุงให้เหมาะสมกับการใช้งานด้านต่าง ๆ โดยเฉพาะในห้องปฏิบัติการขนาดใหญ่ที่ต้องมีการตรวจสอบปฏิกริยาของเม็ดเลือดแดงเป็นจำนวนมาก ทั้งนี้เพื่อพัฒนาชุดการทดสอบโดยพึ่งพาเทคโนโลยีในประเทศ ลดการนำเข้าของผลิตภัณฑ์ที่มีราคาสูงจากต่างประเทศได้
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นักวิจัย ม.ขอนแก่น กับความสำเร็จในการพัฒนาชุดทดสอบ Microtube Gel Test
Source>http://www.myscientists.com/thai_technology/index.php?id=85

ดร.พลาเดช เฉลยกิตติ รักษาการผู้อำนวยการฝ่ายบ่มเพาะธุรกิจเทคโนโลยี อุทยานวิทยาศาสตร์ประเทศไทย ศ.ดร.ชัชนาถ เทพธรานนท์ รองผู้อำนวยการสำนักงานพัฒนาวิทยาศาสตร์และเทคโนโลยีแห่งชาติ และผู้อำนวยการศูนย์บริหารจัดการเทคโนโลยี และ ดร.กัญญวิมว์ กีรติกร ผู้อำนวยการศูนย์พันธุวิศวกรรมและเทคโนโลยีชีวภาพแห่งชาติ คุณนพดล พันธุ์พานิช กรรมการ บริษัท อินโนว์ (ประเทศไทย) จำกัด ร่วมลงนามอนุญาติสัญญาให้ใช้สิทธิ “ชุดทดสอบเพื่อใช้ตรวจหาปฏิกิริยาแอนติบอดีต่อแอนติเจนบนเม็ดเลือดแดง”
ศูนย์พันธุวิศวกรรมและเทคโนโลยีชีวภาพแห่งชาติ หรือ ศูนย์ไบโอเทค ภายใต้สังกัด สำนักงานพัฒนาวิทยาศาสตร์และเทคโนโลยีแห่งชาติหรือ สวทช. ได้สนับสนุน รศ.ดร.อมรรัตน์ ร่มพฤกษ์ คลังเลือดกลาง คณะแพทย์ศาสตร์ มหาวิทยาลัยขอนแก่น ศึกษาวิจัยเรื่อง การพัฒนาชุดทดสอบเพื่อใช้ตรวจหาปฏิกิริยาแอนติเจน-แอนติบอดีต่อเม็ดเลือดแดง โดยมีวัตถุประสงค์เพื่อพัฒนาชุดทดสอบ Microtube Gel Test เพื่อใช้ตรวจหาปฏิกิริยาการจับกลุ่มของเม็ดเลือดแดง

ในวันนี้ (7 ต.ค. 51) ได้จัดให้มีพิธีลงนามสัญญาอนุญาตให้ใช้สิทธิ “ชุดทดสอบเพื่อใช้ตรวจหาปฏิกิริยาแอนติบอดีต่อแอนติเจนบนเม็ดเลือดแดง” ระหว่างมหาวิทยาลัยขอนแก่น ศูนย์ พันธุวิศวกรรมและเทคโนโลยีชีวภาพแห่งชาติ และบริษัท อินโนว์ (ประเทศไทย) จำกัด

ทั้งนี้ การวิจัยเพื่อพัฒนา ถือเป็นหนึ่งในวิสัยทัศน์ของการสนับสนุนทุนวิจัยของ ศูนย์ไบโอเทค เพื่อให้งานวิจัยเป็นหนึ่งในการขับเคลื่อนศักยภาพด้ายเทคโนโลยีของประเทศไทย ดร.กัญญวิมว์ กีรติกร ผู้อำนวยการศูนย์พันธุวิศวกรรมและเทคโนโลยีชีวภาพแห่งชาติ กล่าวว่า “โครงการนี้ประสบความสำเร็จเป็นอย่างสูง เนื่องจากสามารถตอบโจทย์ของผู้ใช้ผลิตภัณฑ์ โดยเริ่มต้นจากตอบโจทย์ของหน่วยงานของผู้วิจัยเองที่ต้องใช้ผลิตภัณฑ์นี้เป็นประจำ ต่อมาก็ถูกนำไปขยายออกไปในวงกว้าง เพื่อเผยแพร่ให้ผู้ใช้งานในวงการเดียวกัน จนปัจจุบันถูกนำส่งต่อไปสู่การผลิตในระดับอุตสาหกรรม กระบวนการดังกล่าวนี้เริ่มต้นเมื่อปี 2547 ถือเป็นการเสริมปัจจัยเพื่อสนับสนุน การทำงานของนักวิจัยซึ่งเดิมมีอยู่แล้วในหน่วยงาน และจากการได้ทำงานร่วมกับนักวิจัยอย่างใกล้ชิด ทำให้สามารถปรับปรุง และพัฒนาแนวทางที่เหมาะสมร่วมกันมาอย่างต่อเนื่อง”

สำหรับ มหาวิทยาลัยขอนแก่น เป็นอีกหนึ่งในมหาวิทยาลัยชั้นนำของประเทศไทยที่มุ่งสู่การเป็นมหาวิทยาลัยแห่งการวิจัยและเป็นสถาบันชั้นนำของอาเซียน “การวิจัยครั้งนี้ได้มุ่งแก้ไขปัญหา การนำเข้าชุดทดสอบที่ใช้ตรวจหาปฏิกิริยาแอนติเจนและแอนติบอดีทางเลือด โดยได้ผลิตเพื่อใช้งานภายในโรงพยาบาลศรีนครินทร์ คณะแพทยศาสตร์ มหาวิทยาลัยขอนแก่น มาเป็นระยะเวลา 4 ปีแล้ว ซึ่งก็ได้ผลเป็นที่น่าพอใจและนำมาสู่การจดทะเบียนสิทธิบัตร” รศ.กิตติชัย ไตรรัตนศิริชัย รองอธิการบดีฝ่ายวิจัยและการถ่ายทอดเทคโนโลยี มหาวิทยาลัยขอนแก่น กล่าว

การมอบสิทธิการถ่ายทอดเทคโนโลยี ชุดทดสอบ Microtube Gel Test นี้ให้แก่ บริษัท อินโนว์ (ประเทศไทย) จำกัด ซึ่งเป็นบริษัทของคนไทยที่เป็นสมาชิกของฝ่ายบ่มเพาะธุรกิจเทคโนโลยี อุทยานวิทยาศาสตร์ประเทศไทย สวทช. “ดิฉันขอแสดงความยินดีกับมหาวิทยาลัยขอนแก่นที่สร้างสรรค์ผลงานวิจัยที่มีคุณค่า และบริษัท อินโนว์ฯ ที่ได้เล็งเห็นถึงประโยชน์ของงานวิจัยนี้ จนนำไปสร้างเป็นผลิตภัณฑ์ออกสู่ตลาดในอนาคตอันใกล้ นอกจากนี้ขอขอบคุณ ไบโอเทค และอุทยานวิทยาศาสตร์ประเทศไทย ที่อยู่เบื้องหลังความสำเร็จที่คอยสนับสนุน และส่งเสริมให้เกิดการนำงานวิจัยไปใช้ในเชิงพาณิชย์” ศ.ดร.ชัชนาถ เทพธรานนท์ รองผู้อำนวยการสำนักงานพัฒนาวิทยาศาสตร์และเทคโนโลยีแห่งชาติ และผู้อำนวยการศูนย์บริหารจัดการเทคโนโลยี กล่าว

ด้าน ดร.พลาเดช เฉลยกิตติ รักษาการผู้อำนวยการฝ่ายบ่มเพาะธุรกิจเทคโนโลยี อุทยานวิทยาศาสตร์ประเทศไทย กล่าวเสริมว่า “ภายใต้ฝ่ายฯการถ่ายทอดดังกล่าวมีวัตถุประสงค์เพื่อให้เกิดการนำงานวิจัยสามารถถ่ายทอดสู่เชิงพาณิชย์ รวมทั้งทำให้สามารถเผยแพร่เทคโนโลยีไปสู่วงกว้าง”

คุณนพดล พันธุ์พานิช กรรมการ บริษัท อินโนว์ (ประเทศไทย) จำกัด กล่าวว่า “ชุดทดสอบ Microtube Gel Test ได้ทำให้การตรวจหมู่เลือดของผู้บริจาคเลือดและผู้รับเลือด มีความถูกต้อง แม่นยำ สะดวก และรวดเร็วยิ่งขึ้นจากวิธีดั้งเดิม และมีต้นทุนถูกกว่าสินค้านำเข้ามาก บริษัทจึงได้เสนอแผนธุรกิจสำหรับชุดทดสอบเจลสำหรับธนาคารเลือดแก่ไบโอเทคและมหาวิทยาลัยขอนแก่น และได้มีการประชุมกันทั้ง 3 ฝ่ายและมีความเห็นร่วมกันที่จะพัฒนาโครงการนี้สู่เชิงพาณิชย์ จึงได้เกิดพิธีลงนามในวันนี้ขึ้น”

ในสถานภาพปัจจุบัน ชุดทดสอบ Microtube Gel Test ที่ รศ.ดร.อมรรัตน์ พัฒนาสำเร็จ ได้มีการยื่นขอรับความคุ้มครองด้านทรัพย์สินทางปัญญาประเภทสิทธิบัตรเรียบร้อยแล้ว จากนี้ไปประเทศไทยจะได้ใช้ผลิตภัณฑ์ที่พัฒนา และผลิตขึ้นจากฝีมือนักวิจัยไทยกันอย่างแพร่หลายต่อไป

Future Medicine

The photonic nanomedicine revolution:
Let the human side of nanotechnology emerge
Naomi J Halas

Department of Electrical & Computer Engineering & the Laboratory for Nanophotonics,
Rice University, 6100 Main St., Houston, TX 77005-1892, USA. halas@rice.edu

Nanoparticle-based photothermal ablation is showing extraordinary promise as an unusually effective and potentially revolutionary cancer therapy. This approach uses light at near-infrared wavelengths that pass through tissue, in combination with gold-based nanoparticles specifically engineered to absorb that light and convert it to heat. The light-absorbing nanoparticles serve as highly localized heat sources that destroy cells in their immediate vicinity by hyperthermia [4]. This method has been shown to be highly effective in extensive animal studies, with tumor remission rates above 90%. Extensive toxicity studies have been performed on nanoshells, the nanoparticles most utilized to date in these studies, and this is being followed by similar studies on other types of noble metal nanoparticles that are also promising candidates for this therapeutic modality. The US FDA has recently granted approval for initial human trials of this therapy for head and neck cancer. Given the extraordinary promise of these potentially revolutionary therapeutic nanodevices and their impending availability, research into nanoparticle-based therapeutics is beginning to move into the next critical phase: the development of nanoparticle-assisted therapeutic practices specifically for clinical use.
One of the most extraordinary aspects of nanoparticle-assisted photothermal therapy for tumor remission is that it is drug free: cell death is induced by the localized heat generated when the nanoparticles absorb near-infrared light. This is an exceedingly important aspect: with heat as the source of cell death, this approach is independent of the specifics of the immune systems of various animals on which it may be tested. This also means that with this therapeutic approach, the nanoparticles can be classified as a device, rather than a drug. They are nanoscale lenses, delivering highly focused light to cancer cells or within tumors much like a lens that captures sunlight delivers enough heat to a leaf to enable it to burst into flames. However, in the case of nanoparticle-based photothermal therapy, the heat required to induce cell death is only approximately 15–20? above physiological temperatures. Because the nanoparticles are devices and not drugs, operating only on heat and light and not interacting chemically with living systems, this therapy, and other variants of this approach, may be available for patients and practitioners in just a few years.
For cancer, this nanoparticle-based strategy will ultimately allow the clinician to remove localized tumors with a simple, minimally invasive, nonsurgical procedure performed, for example, with a portable laser in an outpatient clinic instead of a surgical suite. This could fundamentally revolutionize the treatment of virtually all soft-tissue cancers, transforming this feared, life-threatening disease to an actively managed illness that can be treated and contained prophylactically.
While early detection and treatment of localized, noninvasive tumors is ideal, in reality it is not the typical diagnostic scenario. In any given year, invasive carcinoma diagnoses far outnumber the diagnosed cases of localized cancer. While nanoparticle-based photothermal therapy appears to be highly promising for the removal of localized tumors, an important and immediate challenge is to develop strategies to address more advanced stages of cancer with this powerful new modality. The proliferation of cancer to the lymph nodes directly adjacent to the primary tumor is a key diagnostic for cancer clinicians, and determines the course of treatment. In conventional surgery, these adjacent lymph nodes are typically removed along with the primary tumor. Recent advances in the development of strongly enhanced fluorescent markers for deep-tissue imaging may make resolution at the limit of a few cells possible. Targeted imaging of cancer in lymph nodes, to quantify the proliferation of cancer beyond carcinoma in situ, could be combined with photothermal destruction of targeted cancer cells using nanoparticle-based probes. This would provide a method for removing the cancer cells in the lymph nodes while preserving, largely intact, the lymphatic system of the cancer patient. As markers become available this general approach should be extendable to additional strategies for the treatment of metastatic disease.
The centers of solid tumors are frequently observed to be largely necrotic, resulting from prolonged hypoxia: insufficient availability of oxygen and glucose to meet the metabolic demands of the malignant cells. Because of the decreased blood flow in these tumor regions, they are inaccessible by, and therefore highly resistant to, conventional chemotherapies. One possible scenario for the progression of cancer to its latter, highly fatal stages is that cells surviving in these inaccessible hypoxic regions may themselves be the source of subsequent local recurrence and distant metastasis. One of the body’s responses to the presence of a malignant neoplasm is to recruit peripheral blood monocytes into the tumor, which then differentiate into macrophages. These cells have been shown to promote metastatic disease. One potentially promising scenario is to induce uptake of nanoshells into monocytes, which are then recruited into the hypoxic regions of tumors: the presence of the nanoshells would then permit photothermal destruction of the necrotic region. This type of approach may provide a critical new strategy for thwarting tumor metastasis.
An exciting new use of nanoparticle-assisted photothermal therapy is in delivery methods for gene therapy. It is widely recognized that gene-based therapies hold extraordinary therapeutic promise for cancer: many genetic markers have been discovered, and numerous DNA-based therapeutics have been proposed for the targeting of pathogenic genes for various cancers. Genetic vaccines have also been suggested for certain forms of cancer now believed to have a hereditary basis, such as the 42–57% of prostate cancer cases that correlate with inherited genetic factors. However, while the discovery of gene targets and the development of gene-based therapies at the molecular level has been pursued aggressively for more than 15 years, the transition of these therapies from the research laboratory to the clinic is at a virtual impasse and fraught with severe challenges. Unprotected gene therapy drugs (DNA- or RNA-based) introduced into the bloodstream are rapidly broken down, preventing their diffusion to the region of disease. Viruses, the initial carrier of choice in most gene therapy research, present a variety of potential problems to the patient – toxicity, immune and inflammatory responses, and gene control and targeting issues. The first clinical gene therapy studies utilizing a viral delivery vector resulted in patient death, and had to be terminated in their initial stage. There is a clear critical need for nonviral delivery vectors for gene therapy for this field to advance towards its many clinical applications. Nanoparticle–biomolecule light-actuated complexes are being developed and tested with clinically relevant genetic markers. For example, by combining gold nanoparticles with specific oligonucleotides, the nanoparticle complex can serve as a nonviral gene-delivery vector, where incident light can trigger the release of the nucleotide once the complex has been taken up by cells. Initial release data in cell culture studies show that this approach has outstanding promise for gene delivery. Light-triggered nucleotide release from these nanoparticle–molecule complexes makes them particularly well suited for the localized administration of gene therapy drugs into the tissue or organ of interest.
In conclusion, nanoparticle-assisted, photothermal therapeutic strategies have the capability of providing revolutionary tools in many battles against human disease, with the clear potential for highly effective therapy for cancer and other diseases. Moreover, this approach is unparalleled in its level of noninvasiveness and in its low, essentially nonexistent toxicity. The long-term impact of the development of these new treatment methods will be to change the way we treat cancer. This approach may also provide effective new strategies for treatments of other, lesser known and less-studied diseases such as autoimmune disorders, where few or no treatment options currently exist. In addition to increased efficacy, an extraordinary advantage of nanoparticle-assisted photothermal therapy is that essentially no, or minimal, side effects are expected. Replacing current chemotherapy treatments, with their high level of systemic toxicity and deleterious side effects, with this benign therapeutic approach will greatly increase the quality of life for cancer patients and their families.
Financial & competing interests disclosure The author is the inventor of nanoshells and pioneered nanoparticle-based photothermal therapies along with her collaborators at Rice University (TX, USA), J West and R Drezek. She is the co-founder of Nanospectra Biosciences, Inc. (www.nanospectra.com), a Houston-based company dedicated to the translation of this therapeutic approach into clinical practice. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Source >http://www.futuremedicine.com/doi/full/10.2217/nnm.09.26

Biomedical devices

The devices considered in this section fall into the category of nanobiotechnology, also known as nanomedicine, defined as the application of nanotechnology to human health.One of the most attractive candidate tasks for a radically new approach is the sequencing ofthe human genome. The growing fund of medical experience concerning individual patients’responses to pharmaceutical drugs is revealing significant differences between individuals, whichin many cases might be due to differences in DNA sequence. Despite the tremendousboost to the technology of DNA sequencing that came from the international project to sequencethe (putatively prototypical) human genome, the basic methods applied were the conventionalbiochemical ones; the vast increase in throughput was achieved through massive parallelizationand automation.
The four different DNA “bases” (or nucleotides, symbolized as A,C,G,T) differ not only in the chemical nature, but also in their physical nature, most significantly as regards size and shape.One of the early motivations for developing the atomic force microscope was the hope that thesephysical differences could be revealed by rapidly scanning a single strand of DNA. Although theresolution, at least in the presence of liquid water, has so far proved to be inadequate, alternativeapproaches with the same end in view are being intensively investigated. The favoured schemeis to pass the DNA strand through a nanopore while measuring ionic conductance (of theelectrolyte solution in which the DNA is dissolved), either along or across the pore, with theresolution of a single base. The different nucleotides can be thus distinguished, but it is difficultto capture the DNA and drive it through the pore.
The flagship nanomedical system (rather than device) is the “nanobot”, an autonomous robotenvisaged to be about the size of a bacterium (i.e., about one micrometre in diameter), andcontaining many nanodevices (an energy source, a means of propulsion, an information pro-cessor, environmental sensors, and so forth). When engineering such devices it is importantto note the environment in which they must operate: viscous (highly dissipative), dominatedby friction and fluctuations (Brownian motion), and in which inertia plays a negligible role.This is in contrast to the familiar macroscopic mechanisms that follow Newton’s laws: for thenanobot, force is not given by the product of mass and acceleration, but by the product of thecoefficient of friction and its velocity, together with superimposed random fluctuations. Anyself-propelling nanobot is therefore likely to resemble a motile bacterium rather than a deviceequipped with nanoscale oars or paddles.
Source: Jeremy Rameden," Nanotechnology " 2009

Lab on a chip

Lab on a chip mimics brain chemistry

February 12th, 2008 Johns Hopkins researchers from the Whiting School of Engineering and the School of Medicine have devised a micro-scale tool – a lab on achip – designed to mimic the chemical complexities of the brain. The system should help scientists better understand how nerve cells in the brain work together to form the nervous system.
AmpliChip CYP450 Test – www.AmpliChip.us
Roche Diagnostics US Official Site FDA cleared CYP450 Test

A report on the work appears as the cover story in the February 2008 issue of the British journal Lab on a Chip. ”The chip we’ve developed will make xperiments on nerve cells more simple to conduct and to control,” says Andre Levchenko, Ph.D., associate professor of biomedical engineering at the Johns Hopkins Whiting School of Engineering and faculty affiliate of the Institute for NanoBioTechnology. Nerve cells decide which direction to grow by sensing both the chemical cues flowing through their environment as well as those attached to the surfaces that surround them. The chip, which is made of a plastic-like substance and covered with a glass lid, features a system of channels and wells that allow researchers to control the flow of specific chemical cocktails around single nerve cells.

“It is difficult to establish ideal experimental conditions to study how neurons react to growth signals because so much is happening at once that sorting out nerve cell connections is hard, but the chip, designed by experts in both brain chemistry and engineering, offers a sophisticated way to sort things out,” says Guo-li Ming,
M.D.,Ph.D., associate professor of neurology at the Johns Hopkins School of Medicine and Institute for Cell Engineering.

In experiments with their chip, the researchers put single nerve cells, or rons,onto the chip then introduced specific growth signals (in the form of hemicals).They found that the growing neurons turned and grew toward higher concentrations of certain chemical cues attached to the chip’s surfaces, as well as to signaling molecules free-flowing in solution.

When researchers subjected the neurons to conflicting signals (both surface bound and cues in solution), they found that the cells turned randomly, suggesting that cells do not choose one signal over the other. This,according to Levchenko,supports the prevailing theory that one cue can elicit different responses depending on
a cell’s surroundings. “The ability to combine several different stimuli in the chip resembles a more realistic environment that nerve cells will encounter in the living animal,” Ming says.This in turn will make future studies on the role of neuronal cells in development and regeneration more accurate and complete.

Source: Johns Hopkins Medical Institutions

Nanoparticles Home in on Brain Cancer

Nanoparticles Home in on Brain Cancer
By Nikhil Swaminathan
November 17, 2006

Call them laser-guided smart bombs for brain tumors. Researchers at the University of Michigan announced the testing of a drug delivery system that involves drug-toting nanoparticles and a guiding peptide to target cancerous cells in the brain. Their study finds that via this method more of the drug can be delivered to a tumor's general vicinity. They report their findings in the November 15 issue of Clinical Cancer Research.
The researchers used a pharmaceutical called Photofrin, which is photodynamic, meaning it is activated by a laser after it has entered the bloodstream. As its primary side effect, the drug renders patients photosensitive, and they must remain out of bright sunlight and even unshaded lamps for up to 30 days after receiving treatment. Despite this major drawback, Photofrin is used in the treatment of esophageal, bladder and skin cancers. But their novel delivery system, which relies on the intravenous delivery of 40-nanometer-wide particles to carry the drug, may actually avoid much of the photosensitivity, because less Photofrin circulates in the bloodstream thanks to a peptide called F3. A sequence of 31 amino acids broken off of the protein HMGN2 (high mobility group protein 2), F3 has the ability to penetrate cell membranes. "This peptide acts as a "zip code" in that it enables the binding of the nanoparticles only to blood vessels within the tumor and not normal blood vessels," says Alnawaz Rehemtulla, a radiologist and environmental health scientist who co-authored the study. F3 can detect the expression of a protein called nucleolin, which is a marker on the surface of tumor cells.
Another problem the researchers avoided was having to deliver their medicine in such a way that it could cross the blood-brain barrier, which keeps many substances from entering the brain from the bloodstream. Typical chemotherapies must penetrate this shield to treat tumors. In this case, however, the nontoxic polyacrylamide particles didn't have to cross over via the bloodstream. "The nanoparticles do not need to cross the blood-brain barrier as they were specifically designed to target the blood vessel cells within the tumor," explains radiologist Brian Ross, one of the study's authors. "The treatment should be thought of as an antivascular treatment thereby shutting off the tumor blood flow resulting in the death of the tumor cells through starvation of oxygen and energy sources."
To test the delivery method, researchers divided 34 rats--all who received injections of cancerous cells into their brains--into different groups. Those that received no treatment or got only the laser fared poorly, dying on average within 8.5 days. Those that got Photofrin either intravenously or encapsulated in nanoparticles had a median survival time of 13 days. The group that got F3 with the Photofrin-carrying nanoparticles came through the best: they lived for, on average, 33 days; three of the five in this grouping lived for 60 days, and two of those three appeared tumor-free after six months. By using iron oxide as a contrast agent--to more easily detect where the nanoparticles ended up via MRI--the group determined that twice as much drug with the F3 peptide attached reached the tumor site--10 percent of the total amount administered--compared with when nontargeted nanoparticles were injected.
Ross says that based on the success of the study, the team is investigating if this delivery technology will work for nonphotodynamic therapies. Rehemtulla adds that if other FDA-approved chemotherapeutic agents reach their targets as successfully as Photofrin did, "then we will have developed a way to make cancer drugs more 'tumor-specific,' because they will only get into tumor vasculature and not normal vasculature. This will spare patients from normal tissue toxicity that is commonly associated with almost all chemotherapy."

Source>http://www.scientificamerican.com/article.cfm?id=nanoparticles-home-in-on

The Nanotechnology Revolution Nanomedicine(10)

Molecular Repairs

Cells are made of billions of molecules, each built by molecular machines. These molecules self-assemble to form larger structures, many in dynamic patterns, perpetually disintegrating and reforming. Cell-surgery devices will be
able to make molecules of sorts that may be lacking, while destroying molecules that are damaged or present in excess. They will be able not only to remove viral genes, but to repair chemical and radiation-caused damage to the cell's own genes. Advanced cell surgery devices would be able to repair cells almost regardless of their initial state of damage.By activating and inactivating a cell's genes, they will be able to stimulate cell division and guide what types of cells are formed. This will be a great aid to cell herding and to healing tissues.
As surgeons today rely on the spontaneous, self-organizing ability of cells and tissues to join and heal the parts they manipulate, so cell-surgery devices will rely on the spontaneous self-organizing capabilities of molecules to join and "heal" the parts they put together. Healing of a surgical wound involves sweeping up dead cells, growing new cells, and a slow and genuinely painful process of tissue reorganization. In contrast, the joining of molecules
is almost instantaneous and occurs on a scale far below that of the most sensitive pain receptor. "Healing" will not begin after the repair devices have done their work, as it does in conventional surgery: rather, when they complete their work, the tissue will have been healed.

Healing Body and Limb
The ability to herd cells and to perform molecular repairs and cell surgery will open new vistas for medicine. These abilities apply on a small scale, but their effects can be large scale.Correcting ChemistryIn many diseases, the body as a whole suffers from misregulation of the signaling molecules that travel through
its fluids. Many are rare: Cushing's disease, Grave's disease, Paget's disease, Addison's disease, Conn's syndrome, Prader-Labhart-Willi syndrome. Others are common: millions of older women suffer from osteoporosis, the weakening of bones that can accompany lowered estrogen levels.Diabetes kills frequently enough to rank in the top ten causes of death in the United States; the number of individuals known to have it doubles every fifteen years. It is the leading cause of blindness in the United States, with other complications including kidney damage, cataracts, and cardiovascular damage. Today's molecular
medicine tries to solve these troubles by supplying missing molecules: diabetics inject additional insulin. While helpful, this doesn't cure the disease or eliminate all symptoms. In an era of molecular surgery, physicians could
choose instead to repair the defective organ, so it can regulate its own chemicals again, and to readjust the metabolic properties of other cells in the body to match. This would be a true healing, far better than today's partial fix.
Only now are researchers making progress on another frequent problem of metabolic regulation: obesity. Once this was thought to have one simple cause (consuming excess calories) and one main result (greater roundness
than favored by today's aesthetics), but both assumptions proved wrong. Obesity is a serious medical problem,increasing the risk of diabetes mellitus, osteoarthritis, degenerative diseases of the heart, arteries, and kidneys,
and shortening life expectancy. And the supposed cause, simple overeating, has been shown to be incorrect—something dieters had always suspected, as they watched thinner colleagues gorge and yet gain no weight.

The ability to lay in stores of fat was a great benefit to people once upon a time, when food supplies were irregular, nomadism and marauding bands made food storage difficult and risky, and starvation was a common cause of death. Our bodies are still adapted to that world, and regulate fat reserves accordingly. This is why dieting often has perverse effects. The body, when starved, responds by attempting to build up greater reserves of fat at its next opportunity. The main effect of exercise in weight reduction isn't to burn up calories, but to
signal the body to adapt itself for efficient mobility.
Obesity therefore seems to be a matter of chemical signals within the body, signals to store fat for famine or to become lean for motion. Nanomedicine will be able to regulate these signals in the bloodstream, and to adjust how individual cells respond to them in the body. The latter would even make possible the elusive "spot reduction program" to reshape the distribution of body fat.
Here, as with many potential applications of nanotechnology, the problem may be solved by other means first. Some problems, though, will almost surely require nanomedicine.New Organs and LimbsSo far we've seen how medical nanotechnology would be used in the simpler applications outside tissues—such as in the blood—then inside tissues, and finally inside cells. Consider how these abilities will fit together for victims of automobile and motorcycle accidents.
Nanomanufactured medical devices will be of dramatic value to those who have suffered massive trauma. Take the case of a patient with a crushed or severed spinal cord high in the back or in the neck. The latest research gives hope that when such patients are treated promptly after the injury, paralysis may be at least partially avoidable, sometimes. But those whose injuries weren't treated—including virtually all of today's patients—remain paralyzed. While research continues on a variety of techniques for attempting to aid a spontaneous healing process, prospects for reversing this sort of damage using conventional medicine remain bleak.
With the techniques discussed above, it will become possible to remove scar tissue and to guide cell growth so as to produce healthy arrangements of the cells on a microscopic scale. With the right molecular-scale poking and
prodding of the cell nucleus, even nerve cells of the sorts found in the brain and spinal cord can be induced to divide. Where nerve cells have been destroyed, there need be no shortage of replacements. These technologies will eventually enable medicine to heal damaged spinal cords, reversing paralysis.
The ability to guide cell growth and division and to direct the organization of tissues will be sufficient to regrow entire organs and limbs, not merely to repair what has been damaged. This will enable medicine to restore physical health despite the most grievous injuries.
If this seems hard to believe, recall that medical advances have shocked the world before now. To those in the past, the idea of cutting people open with knives painlessly would have seemed miraculous, but surgical anesthesia is now routine. Likewise with bacterial infections and antibiotics, with the eradication of smallpox, and the vaccine for polio: Each tamed a deadly terror, and each is now half-forgotten history. Our gut sense of what seems likely has little to do with what can and cannot be done by medical technology. It has more to do with our habitual fears, including the fear of vain hopes. Yet what amazes one generation seems obvious and even boring to the next. The first baby born after each breakthrough grows up wondering what all the excitement was about.
Besides, nano-scale medicine won't be a cure-all. Consider a fifty-year-old mentally retarded man, with a mind like a two-year-old's, or a woman with a brain tumor that has spread to the point that her personality has changed: How could they be "healed"? No healing of tissues could replace a missed lifetime of adult experience, nor can it replace lost information from a severely damaged brain. The best physicians could do would be to bring the patients to some physically healthy condition. One can wish for more, but sometimes it won't be
possible.
First AidThroughout the centuries, medicine has been constrained to maintain functioning tissues, since once tissues stop functioning, they can't heal themselves. With molecular surgery to carry out the healing directly, medical priorities change drastically—function is no longer absolutely necessary. In fact, a physician able to use molecular surgery would prefer to operate on nonfunctioning, structurally stable tissue than on tissue that has been allowed to continue malfunctioning until its structure was lost.
Brain tumors are an example: They destroy the brain's structure, and with it the patient's skills, memories, and personality. Physicians in the future should be able to immediately interrupt this process, to stop the functioning of the brain to stabilize the patient for treatment.
Techniques available today can stop tissue function while preserving tissue structure. Greg Fahy, in his work on organ preservation at the American Red Cross, is developing a technique for vitrifying animal kidneys—making
them into a low-temperature, crystal-free glass—with the goal of maintaining their structure such that, when brought back to room temperature, they can be transplanted. Some kidneys have been cooled to -30 ?C, warmed back up, and then functioned after transplantation.
A variety of other procedures can also stabilize tissues on a long-term basis. These procedures enable many cells—but not whole tissues—to survive and recover without help; advanced molecular repair and cell surgery will
presumably tip the balance, enabling cells, tissues, and organs to recover and heal. When applied to stabilizing a whole patient, such a condition can be called biostasis. A patient in biostasis can be kept there indefinitely until
the required medical help arrives. So in the future, the question "Can this patient be restored to health?" will be answered "Yes, if the patient's brain is intact, and with it the patient's mind."
Sandra Lee Adamson of the National Space Society has her eyes on distant goals. Some have proposed that travel to the stars would take generations, preventing anyone on Earth from ever making the trip. But she notes that
biostasis will "give hope to some fearless adventurers who will risk suspension and subsequent reanimation so they can see the stars for themselves."
Plague InsuranceMedical nanotechnologies promise to extend healthy life, but if history is any guide, they may also avert sudden massive death. The word plague is rarely heard today, except in relation to AIDS; it calls up visions of the Black Death of the Middle Ages, when one third of Europe died in 1346-50. A virulent influenza struck in 1918, half lost in the news of the First World War: how many of us realize that it killed at least 20 million? People often act as
though plagues were gone for good, as if sanitation and antibiotics had vanquished them. But as doctors are forever telling their patients, antibiotics kill bacteria, but are useless for viruses. The flu, the common cold,
herpes, and AIDS—none has a really effective treatment, because all are caused by viruses. In some African countries, as much as 10 percent of the population is estimated to be infected with the AIDS-causing HIV virus.
Without a cure soon, the steep rise in deaths from AIDS still lies in the future. AIDS stands as a grim reminder that the great plagues of history are not behind us.
The Threat New diseases continue to appear today as they have throughout history. Today's population, far larger than that of any previous century, provides a huge, fertile territory for their spread.
Today's transportation systems can spread viruses from continent to continent in a single day. When ships sailed or churned their way across the seas, an infected passenger was likely to show full-blown disease before arrival,
permitting quarantine. But few diseases can be guaranteed to show themselves in the hours of a single aircraft flight.So far as is known, every species of organism, from bacterium to whale, is afflicted with viruses. Animal viruses
sometimes "jump the species gap" to infect other animals, or people. Most scientists believe that the ancestors of the AIDS virus could, until recently, infect only certain African monkeys. Then these viruses made the interspecies
jump. A similar jump occurred in the 1960s when scientists in West Germany, working with cells from monkeys in Uganda, suddenly fell ill. Dozens were infected, and several died of a disease that caused both blood clots and
bleeding, caused by what is now named the Marburg virus. What if the Marburg virus had spread with a sneeze, like influenza or the common cold?
We think of human plagues as a health problem, but when they hit our fellow species, we tend to see them from an environmental perspective. In the late 1980s, over half the harbor-seal population in large parts of the North
Sea suddenly died, leading many at first to blame pollution. The cause, though, appears to be a distemper virus that made the jump from dogs. Biologists worry that the virus could infect seal species around the world, since distemper virus can spread by aerosols—that is, by coughing—and seals live in close physical contact. So far its mortality rate has been 60 to 70 percent.

What of AIDS itself: Could it change and give rise to a form able to spread, say, as colds do? Nobel Laureate Howard M. Temin has said, "I think that we can very confidently say that this can't happen." Nobel Laureate
Joshua Lederberg, president of Rockefeller University in New York City, replied, "I don't share your confidence about what can and cannot happen." He points out that "there is no reason a great plague could not happen again. . . .We live in evolutionary competition with microbes—bacteria and viruses. There is no guarantee that we will be the survivors."
Our Inadequate AbilitiesBacterial diseases are mostly controllable today. Sanitation limits the ways in which plague can spread. These measures are just good enough to lull us into imagining the problem is solved.
Viruses are common, viruses mutate; some spread through the air, and some are deadly. Plagues show that fast-spreading diseases can be deadly, and effective antiviral drugs are still rare.
The only really effective treatments for viral diseases are preventive, not curative. They work either by preventing exposure, or by exposing the body beforehand to dead or harmless or fragmentary forms of the virus, to prepare
the immune system for future exposure. As the long struggle for an AIDS vaccine shows, one cannot count on modern medicine to identify a new virus and produce an effective vaccine within a single month or year or even a
single decade. But influenza epidemics spread fast, and Marburg II or AIDS II or something entirely new and deadly may do the same.
Doing BetterThe deaths from the next great plague could have begun in a village last week, or could begin next year, or a year before we learn to deal with new viral illnesses promptly and effectively. With luck, the plague will wait until
a year after.Immune machines could be set to kill a new virus as soon as it is identified. The instruments nanotechnology brings will make viral identification easy. Some day, the means will be in place to defend human life against viral
catastrophe.
From eliminating viruses to repairing individual cells, improving our control of the molecular world will improve health care. Immune machines working in the bloodstream seem about as complex as some engineering projects human beings have already completed—projects like large satellites. Other medical nanotechnologies seem to be of a higher order of complexity.
On Solving Hard ProblemsSomewhere in the progression from relatively simple immune devices to molecular surgery, we've crossed the fuzzy line between systems that teams of clever biomedical engineers could design in a reasonable length of time and ones that might take decades or prove impossibly complex. Designing a nanomachine capable of entering a cell, reading its DNA, finding and removing a deadly viral DNA sequence, and then restoring the cell to normal would be a monumental job. Such tasks are advanced applications of nanotechnology, far beyond mere computers, manufacturing equipment, and half-witted "smart materials."
To succeed within a reasonable number of years, we may need to automate much of the engineering process, including software engineering. Today's best expert systems are nowhere near sophisticated enough. The software must be able to apply physical principles, engineering rules, and fast computation to generate and test new designs. Call it automated engineering.
Automated engineering will prove useful in advanced nanomedicine because of the sheer number of small problems to be solved. The human body contains hundreds of kinds of cells forming a huge number of tissues and organs. Taken as a whole (and ignoring the immune system), the body contains hundreds of thousands of different kinds of molecules. Performing complex molecular repairs on a damaged cell might require solving millions of separate, repetitive problems. The molecular machinery in cell surgery devices will need to be
controlled by complex software, and it would be best to be able to delegate the task of writing that software to an automated system. Until then, or until a lot of more conventional design work gets done, nanomedicine will have to focus on simpler problems.
AgingWhere does aging fit in the spectrum of difficulty? The deterioration that comes with aging is increasingly recognized as a form of disease, one that weakens the body and makes it susceptible to a host of other diseases.
Aging, in this view, is as natural as smallpox and bubonic plague, and more surely fatal. Unlike bubonic plague, however, aging results from internal malfunctions in the molecular machinery of the body, and a medical
condition with so many different symptoms could be complex.
Surprisingly, substantial progress is being made with present techniques, without even a rudimentary ability to perform cell surgery in a medical context. Some researchers believe that aging is primarily the result of a fairly
small number of regulatory processes, and many of these have already been shown to be alterable. If so, aging may be tackled successfully before even simple cell repair is available. But the human aging process is not well
enough understood to enable a confident projection of this; for example, the number of regulatory processes is not yet known. A thorough solution may well require advanced nanotechnology-based medicine, but a thorough solution seems possible. The result would not be immortality, just much longer, healthier lives for those who want them.
Restoring SpeciesA challenging problem related to medicine (and to biostasis) is that of species restoration. Today, researchers are carefully preserving samples from species now becoming extinct. In some cases, all they have are tissue samples. For other species, they've been able to save germ cells in the hope that they will be able to implant fertilized eggs into related species and thus bring the (nearly?) extinct species back.Each cell typically contains the organism's complete genetic information, but what can be done with this? Many researchers today collect samples for preservation thinking only of the implantation scenario: one that they know has already been made to work. Other researchers are taking a broader view: the Center for Genetic Resources
and Heritage at the University of Queensland is a leader in the effort. Daryl Edmondson, coordinator of the gene library, explains that the center is unique because it will "actively collect data. Most other libraries simply collate
their own collections." Director John Mattick describes it as a "genetic Louvre" and points out that if genes from today's endangered species aren't preserved, "subsequent generations will see we had the technology to keep
[DNA] software and will ask why we didn't do it." With this information and the sorts of molecular repair and cell-surgery capabilities we have discussed, lost species can someday be returned to active life again as habitats are restored.
One such center isn't enough: the Queensland center focuses on Australian species (naturally enough) and has limited funds. Besides, anything so precious as the genetic information of an endangered species should be stored
in many separate locations for safety. We need to take out an insurance policy on Earth's genetic diversity with a broader network of genetic libraries, concentrating special attention on gathering biological samples from the fast
-disappearing rain forests. Scientific study can wait: the urgency of the situation calls for a vacuum-cleaner approach. The Foresight Institute is promoting this effort through its BioArchive Project; interested readers can
write to the address at the end of the Afterword.

Source
>http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(9)

Working on Cells

Moving through tissues without leaving a trail of disruption will require devices able to manipulate and direct the motions of cells, and to repair them. Much remains to be learned—and will be easy to learn with nanoscale tools—but today's knowledge of cells is enough for a start on the problem of how to do surgery on cells.
Cell biology is a booming field, even today. Cells can be made to live and grow in laboratory cultures if they are placed in a liquid with suitable nutrients, oxygen, and the rest. Even with today's crude techniques, much has been learned about how cells respond to different chemicals, to different neighbors, and even to being poked and cut with needles. Conducting a rough sort of surgery on individual cells has been routine for many years in scientific laboratories.
Today, researchers can inject new DNA into cells using a tiny needle; small punctures in a cell membrane automatically reseal. But both these techniques use tools that on a cellular scale are large and clumsy—like doing surgery with an ax or a wrecking ball, instead of a scalpel. Nano-scale tools will enable medical procedures involving delicate surgery on individual cells.
Eliminating Viruses by Cell SurgerySome viral diseases will respond to treatments that destroy viruses in the nose and throat, or in the bloodstream.
The flu and common cold are examples. Many others would be greatly improved by this, but not eliminated. All viruses work by injecting their genes into a cell and taking over its molecular machinery, using it to produce more viruses. This is part of what makes viral illnesses so hard to treat—most of the action is performed by the body's own molecular machines, which can't be interfered with on a wholesale basis. When the immune system deals with a viral illness, it both attacks free virus particles before they enter cells, and attacks infected cells before they can churn out too many more virus particles.
Some viruses, though, insert their genes among the genes of the cell, and lay low. The cell can seem entirely normal to the immune system, for months or years, until the viral genes are triggered into action and begin the infective process anew. This pattern is responsible for the persistence of herpes nfections, and for the slow, deadly progress of AIDS.
These viruses can be eliminated by molecular-level cellular surgery. The required devices could be small enough to fit entirely within the cell, if need be. Greg Fahy, who heads the Organ Cryopreservation Project at the American Red Cross's Jerome Holland Transplantation Laboratory, writes, "Calculations imply that molecular sensors, molecular computers, and molecular effectors can be combined into a device small enough to fit easily inside a single cell and powerful enough to repair molecular and structural defects (or to degrade foreign structures such as viruses and bacteria) as rapidly as they accumulate. . . .There is no reason such systems cannot be built and function as designed."
Equally well, a cell surgery device located outside a cell could reach through the membrane with long probes. At the ends of the probes would be tools and sensors along with, perhaps, a small auxiliary computer. These would
be able to reach through multiple membranes, unpackage and uncoil DNA, read it, repackage it, and recoil it, "proofreading" the DNA by comparing the sequences in one cell to the sequences of other cells.
On reading the genetic sequence spelling out the message of the AIDS virus, a molecular surgery machine could be programmed to respond like an immune machine, destroying the cell. But it would seem to make more sense simply to cut out the AIDS virus genes themselves, and reconnect the ends as they were before infection. By doing this, and killing any viruses found in the cell, the procedure would restore the cell to health.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle) >http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(8)

Rebuilding Tissues

Again, skin provides easy examples and may be a natural place to start in practice. People often want hair where they have bare skin, and bare skin where they have hair. Cell herding machines could move or destroy hair follicle
cells to eliminate an unwanted hair, or grow more of the needed cells and arrange them into a working follicle where a hair is desired. By adjusting the size of the follicle and the properties of some of the cells, hairs could be
made coarser, or finer, or straighter, or curlier. All these changes would involve no pain, toxic chemicals, or stench. Cell-herding devices could move down into the living layers of skin, removing unwanted cells, stimulating the growth of new cells, narrowing unnaturally prominent blood vessels, insuring good circulation by guiding the growth of any needed normal blood vessels, and moving cells and fibers around so as to eliminate even deep wrinkles.
At the opposite end of the spectrum, cell herding will revolutionize treatment of life-threatening conditions. For example, the most common cause of heart disease is reduced or interrupted supply of blood to the heart muscle.
In pumping oxygenated blood to the rest of the body, the heart diverts a portion for its own use though the coronary arteries. When these blood vessels become constricted, we speak of coronary-artery disease. When they are blocked, causing heart muscle tissue to die, we speak of someone "having a coronary," another term for heart attack.
Devices working in the bloodstream could nibble away at atherosclerotic deposits, widening the affected blood vessels. Cell herding devices could restore artery walls and artery linings to health, by ensuring that the right cells
and supporting structures are in the right places. This would prevent most heart attacks.
But what if a heart attack has already destroyed muscle tissue, leaving the patient with a scarred, damaged, and poorly functioning heart? Once again, cell-herding devices could accomplish repairs, working their way into the
scar tissue and removing it bit by bit, replacing it with fresh muscle fiber. If need be, this new fiber can be grown by applying a series of internal molecular stimuli to selected heart muscle cells to "remind" them of the instructions for growth that they used decades earlier during embryonic development.
Cell-herding capabilities should also be able to deal with the various forms of arthritis. Where this is due to attacks from the body's own immune system, the cells producing the damaging antibodies can be identified and eliminated. Then a cell-herding system would work inside the joint where it would remove diseased tissues, calcified spurs, and so forth, then rework patterns of cells and intercellular material to form a healthy, smoothly working, and pain-free joint. Clearly, learning to repair hearts and learning to repair joints will have some basic technologies in common, but much of the research and development will have to be devoted to specific tissues and specific circumstances. A similar process—but again, specially adapted to the circumstances at hand—could
be used to strengthen and reshape bone, correcting osteoporosis.

In dentistry, this sort of process could be used to fill cavities, not with amalgam, but with natural dentin and enamel. Reversing the ravages of periodontal disease will someday be straightforward, with nanomedical devices
to clean pockets, join tissues, and guide regrowth. Even missing teeth could be regrown, with enough control over cell behavior.
Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle) >http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(7)

Working Within Tissues

In most parts of the body, the finest blood vessels, capillaries, pass within a few cell diameters of every point. Certain white blood cells can leave these vessels to move among the neighboring cells. Immune machines and similar devices, being even smaller, could do likewise. In some tissues, this will be easy, in some harder, but with careful design and testing, essentially any point of the body should become accessible for healing repairs.
Merely fighting organisms in the bloodstream would be a major advance, cutting their numbers and inhibiting their spread. Roving medical nanomachines, though, will be able to hunt down invaders throughout the body and eliminate them entirely.
Eliminating InvadersCancers are a prime example. The immune system recognizes and eliminates most potential cancers, but some get by. Physicians can recognize cancer cells by their appearance and by molecular markers, but they cannot always remove them all through surgery, and often cannot find a selective poison. Immune machines, however, will have no difficulty identifying cancer cells, and will ultimately be able to track them down and destroy them
wherever they may be growing. Destroying every cancer cell will cure the cancer.
Bacteria, protozoa, worms, and other parasites have even more obvious molecular markers. Once identified, they could be destroyed, ridding the body of the disease they cause. Immune machines thus could deal with tuberculosis, strep throat, leprosy, malaria, amoebic dysentery, sleeping sickness, river blindness, hookworm, flukes, candida, valley fever, antibiotic-resistant bacteria, and even athlete's foot. All are caused by invading cells or larger organisms (such as worms). Health officials estimate that parasitic diseases, common in the Third World, affect more than one billion people. For many of these diseases, no satisfactory drug treatment exists. All can eventually be eliminated as threats to human health by a sufficiently advanced form of nanomedicine.
Herding CellsDestroying invaders will be helpful, but injuries and structural problems pose other problems. Truly advanced medicine will be able to build up and restructure tissues. Here, medical nanodevices can stimulate and guide the
body's own construction and repair mechanisms to restore healthy tissue.
What is healthy tissue? It consists of normal cells in normal patterns in a normal matrix all organized in a normal relationship to the surrounding tissues. Surgeons today (with their huge, crude tools) can fix some problems at
the tissue level. A wound disrupts the healthy relationship between two different pieces of tissue, and surgical glues and sutures can partly remedy this problem by holding the tissues in a position that promotes healing.
Likewise, coronary artery bypass surgery brings about a more healthy overall configuration of tissues—one that provides working plumbing to supply blood to the heart muscle. Surgeons cut and stitch, but then they must rely
on the tissue to heal its wounds as best it can.
Healing establishes healthy relationships on a finer scale. Cells must divide, grow, migrate, and fill gaps. They must reorganize to form properly connected networks of fine blood vessels. And cells must lay down materials to form the structural, intercellular matrix—collagen to provide the proper shape and toughness, or mineral grains to provide rigidity, as in bone. Often, they lay down unwanted scar tissue instead, blocking proper healing.
With enough knowledge of how these processes work (and nanoinstruments can help gather that knowledge) and with good enough software to guide the process—a more difficult challenge—medical nanomachines will be able
to guide this healing process. The problem here is to guide the motion and behavior of a mob of active, living cells—a process that can be termed cell herding.
Cells respond to a host of signals from their environment: to chemicals in the surrounding fluids, to signal molecules on neighboring cells, and to mechanical forces applied to them. Cell-herding devices would use these signals to spur cell division where it is needed and to discourage it where it is not. They would nudge cells to encourage them to migrate in appropriate directions, or would simply pick them up, move them along, and deliver them where needed, encouraging them to nestle into a proper relationship with their neighbors. Finally, they would stimulate cells to surround themselves with the proper intercellular-matrix materials. Or—like the owner of a small dog who, on a cold day, wraps the beast in a wool jacket—they would directly build the proper
surrounding structures for the cell in its new location.
In this way, cooperating teams of cell-herding devices could guide the healing or restructuring of tissues, ensuring that their cells form healthy patterns and a healthy matrix and that those tissues have a healthy relationship to their surroundings. Where necessary, cells could even be adjusted internally, as we will discuss later.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle) >http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(6)

Working Outside Tissues

One approach to nanomedicine would make use of microscopic mobile devices built using molecular-manufacturing equipment. These would resemble the ecosystem protectors and mobile cleanup machines discussed in the last chapter. Like them, they would either be biodegradable, self-collecting, or collected by something else once they were done working. Like them, they would be more difficult to develop than simple,fixed-location nanomachines, yet clearly feasible and useful. Development will start with the simpler applications, so let's begin by looking at what can be done without entering living tissues.
The skin is the body's largest organ, and its exposed position subjects it to a lot of abuse. This exposed position,though, also makes it easier to treat. Among the earlier applications of molecular manufacturing may be those popular, quasimedical products, cosmetics. A cream packed with nanomachines could do a better and more selective job of cleaning than any product can today. It could remove the right amount of dead skin, remove excess oils, add missing oils, apply the right amounts of natural moisturizing compounds, and even achieve the elusive goal of "deep pore cleaning" by actually reaching down into pores and cleaning them out. The cream could be a smart material with smooth-on, peel-off convenience.
The mouth, teeth, and gums are amazingly troublesome. Today, daily dental care is an endless cycle of brushing and flossing, of losing ground to tooth decay and gum disease as slowly as possible. A mouthwash full of smart nanomachines could do all that brushing and flossing do and more, and with far less effort—making it more likely to be used.
This mouthwash would identify and destroy pathogenic bacteria while allowing the harmless flora of the mouth to flourish in a healthy ecosystem. Further, the devices would identify particles of food, plaque, or tartar, and lift them from teeth to be rinsed away. Being suspended in liquid and able to swim about, devices would be able to reach surfaces beyond reach of toothbrush bristles or the fibers of floss. As short-lifetime medical nanodevices, they could be built to last only a few minutes in the body before falling apart into materials of the sort found in foods (such as fiber). With this sort of daily dental care from an early age, tooth decay and gum disease would likely never arise. If under way, they would be greatly lessened.
Going beyond this superficial treatment would involve moving among and modifying cells. Let's consider what can be done with this treatment inside the body, but outside the body's tissues. The bloodstream carries everything from nutrients to immune-system cells, with chemical signals and infectious organisms besides.Medical nanodevices could augment the immune system by finding and disabling unwanted bacteria and viruses.
The immune device in the foreground has found a virus; the other has touched a red blood cell. Adapted from Scientific American, January 1988. Here, it is useful to think in terms of medical nanomachines that resemble small submarines. Each of these is large enough to carry a nanocomputer as powerful as a mid-1980s mainframe, along with a huge database (a billion bytes), a complete set of instruments for identifying biological surfaces, and tools
for clobbering viruses, bacteria, and other invaders. Immune cells, as we've seen, travel through the bloodstream checking surfaces for foreignness and—when working properly—attacking and eliminating what should not be
there. These immune machines would do both more and less. With their onboard sensors and computers, they will be able to react to the same molecular signals that the immune system does, but with greater discrimination.
Before being sent into the body on their search-and-destroy mission, they could be programmed with a set of characteristics that lets them clearly distinguish their targets from everything else. The body's immune system can
respond only to invading organisms that had been encountered by that individual's body. Immune machines,however, could be programmed to respond to anything that had been encountered by world medicine.
Immune machines can be designed for use in the bloodstream or the digestive tract (the mouthwash described above used these abilities in hunting down harmful bacteria). They could float and circulate, as antibiotics do,
while searching for intruders to neutralize. To escape being engulfed by white blood cells making their own patrols, immune machines could display standard molecules on their surface-molecules the body knows and trusts already—like a fellow police officer wearing a familiar uniform.
When an invader is identified, it can be punctured, letting its contents spill out and ending its effectiveness. If the contents were known to be hazardous by themselves, then the immune machine could hold on to it long enough
to dismantle it more completely.
How will these devices know when it's time to depart? If the physician in charge is sure the task will be finished within, say, one day, the devices prescribed could be of a type designed to fall apart after twenty-four hours. If the treatment time needed is variable, the physician could monitor progress and stop action at the appropriate time by sending a specific molecule—aspirin perhaps, or something even safer—as a signal to stop work. The inactivated devices would then be cleared out along with other waste eliminated from the body.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle) >http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(5)

Nanotechnology in Medicine

Developments in nanotechnology will result in improved medical sensors. As protein chemist Bill DeGrado notes, "Probably the first use you may see would be in diagnostics: being able to take a tiny amount of blood from somebody, just a pinprick, and diagnose for a hundred different things. Biological systems are already able to do that, and I think we should be able to design molecules or assemblies of molecules that mimic the biological system."
In the longer term, though, the story of nanotechnology in medicine will be the story of extending surgical control to the molecular level. The easiest applications will be aids to the immune system, which selectively attack
invaders outside tissues. More difficult applications will require that medical nanomachines mimic white blood cells by entering tissues to interact with their cells. Further applications will involve the complexities of molecular-level surgery on individual cells.
As we look at how to solve various problems, you'll notice that some that look difficult today will become easy,while others that might seem easier turn out to be more difficult. The seeming difficulty of treating disorders is always changing: Once polio was frequent and incurable, today it is easily prevented. Syphilis once caused steady physical decline leading to insanity and death; now it is cured with a shot.
Athlete's foot has never been seen as a great scourge, yet it remains hard to cure. Likewise with the common cold. This pattern will continue: Deadly diseases may be easily dealt with, while minor ills remain incurable, or vice versa. As we will see, a mature nanotechnology-based medicine will be able to deal with almost any physical problem, but the order of difficulty may be surprising. Nature cares nothing for our sense of appropriateness. Horribleness and difficulty just aren't the same thing.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle) >http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(4)

Medicine Today

When the body's working, building, and battling goes awry, we turn to medicine for diagnosis and treatment. Today's methods, though, have obvious shortcomings.Crude MethodsDiagnostic procedures vary widely, from asking a patient questions, through looking at X-ray shadows, through
exploratory surgery and the microscopic and chemical analysis of materials from the body. Doctors can diagnose many ills, but others remain mysteries. Even a diagnosis does not imply understanding: doctors could diagnose
infections before they knew about germs, and today can diagnose many syndromes with unknown causes. After years of experimentation and untold loss of life, they can even treat what they don't understand—a drug may
help, though no one knows why.Leaving aside such therapies as heating, massaging, irradiating, and so forth, the two main forms of treatment
are surgery and drugs. From a molecular perspective, neither is sophisticated.
Surgery is a direct, manual approach to fixing the body, now practiced by highly trained specialists. Surgeons sew together torn tissues and skin to enable healing, cut out cancer, clear out clogged arteries, and even install pacemakers and replacement organs. It's direct, but it can be dangerous: anesthetics, infections, organ rejection, and missed cancer cells can all cause failure. Surgeons lack fine-scale control. The body works by means of molecular machines, most working inside cells. Surgeons can see neither molecules nor cells, and can repair neither.

Drug therapies affect the body at the molecular level. Some therapies—like insulin for diabetics—provide materials the body lacks. Most—like antibiotics for infections—introduce materials no human body produces. A drug consists of small molecules; in our simulated molecular world, many would fit in the palm of your hand. These molecules are dumped into the body (sometimes directed to a particular region by a needle or the like), where they mix and wander through blood and tissue. They typically bump into other molecules of all sorts in all places,but only stick to and affect molecules of certain kinds.
Antibiotics like penicillin are selective poisons. They stick to molecular machines in bacteria and jam them, thus fighting infection. Viruses are a harder case because they are simpler and have fewer vulnerable molecular
machines. Worms, fungi, and protozoa are also difficult, because their molecular machines are more like those found in the human body, and hence harder to jam selectively. Cancer is the most difficult of all. Cancerous
growths consist of human cells, and attempts to poison the cancer cells typically poison the rest of the patient as well.
Other drug molecules bind to molecules in the human body and modify their behavior. Some decrease the secretion of stomach acid, others stimulate the kidneys, many affect the molecular dynamics of the brain.Designing drug molecules to bind to specific targets is a growth industry today, and provides one of the many short-term payoffs that is spurring developments in molecular engineering.

Limited Abilities
Current medicine is limited both by its understanding and by its tools. In many ways, it is still more an art than a science. Mark Pearson of Du Pont points out, "In some areas, medicine has become much more scientific, and in others not much at all. We're still short of what I would consider a reasonable scientific level. Many people don't realize that we just don't know fundamentally how things work. It's like having an automobile, and hoping that by taking things apart, we'll understand something of how they operate. We know there's an engine in the front and we know it's under the hood, we have an idea that it's big and heavy, but we don't really see the rings that allow pistons to slide in the block. We don't even understand that controlled explosions are responsible for providing the energy that drives the machine."
Better tools could provide both better knowledge and better ways to apply that knowledge for healing. Today's surgery can rearrange blood vessels, but is far too coarse to rearrange or repair cells. Today's drug therapies can target some specific molecules, but only some, and only on the basis of type. Doctors today can't affect molecules in one cell while leaving identical molecules in a neighboring cell untouched because medicine today cannot apply surgical control to the molecular level.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle) >http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(3)

The Body As BattlefieldAssaults from outside the body turn it into a battlefield where the aggressors sometimes get the upper hand.
From parasitic worms to protozoa to fungi to bacteria to viruses, organisms of many kinds have learned to live by
entering the body and using their molecular machinery to build more of themselves from the body's building
blocks. To meet this onslaught, the body musters the defenses of the immune system—an armada of its own
molecular machines. Your body's own amoebalike white blood cells patrol the bloodstream and move out into
tissues, threading their way between other cells, searching for invaders.
How can the immune system distinguish the hundreds of kinds of cells that should be in the body from the
invading cells and viruses that shouldn't? This has been the central question of the complex science of
immunology. The answer, as yet only partially understood, involves a complex interplay of molecules that
recognize other molecules by sticking to them in a selective fashion. These include free-floating antibodies—which
are a bit like bumbling guided missiles—and similar molecules that are bound to the surface of white blood cells
and other cells of the immune system, enabling them to recognize foreign surfaces on contact.
This system makes life possible, defending our bodies from the fate of meat left at room temperature. Still, it lets
us down in two basic ways.
First, the immune system does not respond to all invaders, or responds inadequately. Malaria, tuberculosis,
herpes, and AIDS all have their strategies for evading destruction. Cancer is a special case in which the invaders
are altered cells of the body itself, sometimes successfully masquerading as healthy cells and escaping detection.
Second, the immune system sometimes overresponds, attacking cells that should be left alone. Certain kinds of
arthritis, as well as lupus and rheumatic fever, are caused by this mistake. Between attacking when it shouldn't
and not attacking when it should, the immune system often fails, causing suffering and death.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle) >http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%
2Fen.wikipedia.org%2Fwiki%2FNanotechnology

The Nanotechnology Revolution Nanomedicine(2)

The Body As Construction Site
In growing, healing, and renewing tissue, the body is a construction site. Cells take building materials from the bloodstream. Molecular machinery programmed by the cell's genes uses these materials to build biological structures: to lay down bone and collagen, to build whole new cells, to renew skin, and to heal wounds.
With the exception of tooth fillings and other artificial implants, everything in the human body is constructed by molecular machines. These molecular machines build molecules, including more molecular machines. They clear away structures that are old or out of place, sometimes using machinery like digestive enzymes to take structures apart.
During tissue construction, whole cells move about, amoebalike: extending part of themselves forward, attaching, pulling their material along, and letting go of the former attachment site behind them. Individual cells contain a dynamic pattern of molecules made of components that can break down but can also be replaced. Some molecular machines in the cell specialize in digesting molecules that show signs of damage, allowing them to be replaced by fresh molecules made according to genetic instructions. Components inside cells form their complex patterns by self-assembly, that is, by sticking to the proper partners.
Failures in construction increase as we age. Teeth wear and crack and aren't replaced; hair follicles stop working; skin sags and wrinkles. The eye's shape becomes more rigid, ruining close vision. Younger bodies can knit together broken bones quickly, making them stronger than before, but osteoporosis can make older bones so fragile that they break under minor stress.
Sometimes construction is botched from the beginning due to a missing or defective genetic code. In hemophilia, bleeding fails to stop due to the lack of blood clotting factor. Construction of muscle tissue is disrupted in 1 in 3,300 male births by muscular dystrophy, in which muscles are gradually replaced by scar tissue and fat; the molecule "dystrophin" is missing. Sickle cell anemia results from abnormal hemoglobin molecules.
Paraplegics and quadriplegics know that some parts of the body don't heal well. The spinal cord is an extreme—and extremely serious—case, but scarring and improper regrowth of tissues result from many accidents. If tissues always regrew properly, injury would do no permanent physical damage.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle)

Nanotechnology Revolution(1)

Our bodies are filled with intricate, active molecular structures. When those structures are damaged, health suffers. Modern medicine can affect the workings of the body in many ways, but from a molecular viewpoint it remains crude indeed. Molecular manufacturing can construct a range of medical instruments and devices with far greater abilities. The body is an enormously complex world of molecules. With nanotechnology to help, we can learn to repair it.
The Molecular Body
To understand what nanotechnology can do for medicine, we need a picture of the body from a molecular perspective. The human body can be seen as a workyard, construction site, and battleground for molecular machines. It works remarkably well, using systems so complex that medical science still doesn't understand many of them. Failures, though, are all too common.
The Body As Workyard
Molecular machines do the daily work of the body. When we chew and swallow, muscles drive our motions. Muscle fibers contain bundles of molecular fibers that shorten by sliding past one another.
In the stomach and intestines, the molecular machines we call digestive enzymes break down the complex molecules in foods, forming smaller molecules for use as fuel or as building blocks. Molecular devices in the lining of the digestive tract carry useful molecules to the bloodstream.
Meanwhile, in the lungs, molecular storage devices called hemoglobin molecules pick up oxygen. Driven by molecular fibers, the heart pumps blood laden with fuel and oxygen to cells. In the muscles, fuel and oxygen drive contraction based on sliding molecular fibers. In the brain, they drive the molecular pumps that charge nerve cells for action. In the liver, they drive molecular machines that build and break down a whole host of molecules. And so the story continues through all the work of the body.
Yet each of these functions sometimes fails, whether through damage or inborn defect.

Source:
>1991 "Nanomedicine," Chapter 10, Unbounding the Future (K. Eric Drexler, Christine Peterson, Gayle Pergamit)
>Dec. 1994 "Nanotechnology and Medicine" (Ralph C. Merkle)
>http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&zu=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FNanotechnology

Age of Convergence

Nanomedicine is the medical application of nanotechnology. It covers areas such as nanoparticle drug delivery and possible future applications of molecular nanotechnology (MNT) and nanovaccinology. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials Nanomedicine research is directly funded, with the US National Institutes of Health in 2005 funding a five-year plan to set up four nanomedicine centers. In April 2006, the journal Nature Materials estimated that 130 nanotech-based drugs and delivery systems were being developed worldwide
In the near future, advancement in nanomedicine will deliver a valuable set of research tools and clinically helpful devices. The National Nanotechnology Initiative expects new commercial applications in the pharmaceutical industry that will include advanced drug delivery systems, new therapies, and in vivo imaging. The most important innovations are taking place in drug delivery which involves developing nanoscale particles or molecules to improve bioavailability. Bioavailability refers to the presence of drug molecules where they are needed in the body and where they will do the most good. Drug delivery focuses on maximizing bioavailability both at specific places in the body and over a period of time. Over 65 billion dollars is wasted every year because of poor bioavailability. In vivo imaging is another area where tools and devices are being developed. Using nanoparticle contrast agents, images such as ultrasound and MRI have a favorable distribution and improved contrast. The new therapies and surgeries that are being developed might be effective in treating illnesses and diseases such as cancer. Finally, a shift from the possible to the potential will be made when nanorobots such as neuro-electronic interfaces and cell repair machines are discussed. Drug delivery systems, lipid- or polymer-based nanoparticles, can be designed to improve the pharmacological and therapeutic properties of drugs. The strength of drug delivery systems is their ability to alter the pharmacokinetics and biodistribution of the drug. Nanoparticles have unusual properties that can be used to improve drug delivery. Where larger particles would have been cleared from the body, cells take up these nanoparticles because of their size. Complex drug delivery mechanisms are being developed, including the ability to get drugs through cell walls and into cells. Efficiency is important because many diseases depend upon processes within the cell and can only be impeded by drugs that make their way into the cell. Triggered response is one way for drug molecules to be used more efficiently. Drugs are placed in the body and only activate on encountering a particular signal. For example, a drug with poor solubility will be replaced by a drug delivery system where both hydrophilic and hydrophobic environments exist, improving the solubility. Also, a drug may cause tissue damage, but with drug delivery, regulated drug release can eliminate the problem. If a drug is cleared too quickly from the body, this could force a patient to use high doses, but with drug delivery systems clearance can be reduced by altering the pharmacokinetics of the drug. Poor biodistribution is a problem that can affect normal tissues through widespread distribution, but the particulates from drug delivery systems lower the volume of distribution and reduce the effect on non-target tissue. Potential nanodrugs will work by very specific and well-understood mechanisms, one of the major impacts of nanotechnology and nanoscience will be in leading development of completely new drugs with more useful behavior and less side effects.

Biomarker

Biomarker discovery is the process by which biomarkers are discovered. It is a medical term. Many commonly used blood tests in medicine are biomarkers. The way that these tests have been found can be seen as biomarker discovery. However, their identification has mostly been a one-at-a time approach. Many of these well-known tests have been identified based on clear biological insight, from physiology or biochemistry. This means that only a few markers at a time have been considered. One example of this way of biomarker discovery is the use of injections of inulin for measuring kidney function. From this, one discovered a naturally occurring molecule, creatinine, that enabled the same measurements to be made easily without injections. This can be seen as a serial process.
The recent interest in biomarker discovery is because new molecular biologic techniques promise to find relevant markers rapidly, without detailed insight into mechanisms of disease. By screening many possible biomolecules at a time, a parallel approach can be tried. Genomics and proteomics are some technologies that are used in this process. Significant technical difficulties remain. There is considerable interest in biomarker discovery from the pharmaceutical industry. Blood test or other biomarkers could serve as intermediate markers of disease in clinical trials, and also be possible drug targets.

Source:>http://bioinformations.info/nano-bioengineering.html

ยาชานาโน

ยาชานาโนซึมผ่านผิวหนัง

จุฬาฯประยุกต์ใช้เทคโนโลยีนาโน ออกแบบระบบนำส่งยาชาในรูปแบบยาทาแทนยาฉีด เล็งสนองความต้องการธุรกิจความงาม รวมถึงการผ่าตัดในคนไข้เด็ก รศ.ดร.สุวบุญจิรชาญชัย รองผู้อำนวยการฝ่ายการวิจัย วิทยาลัยปิโตรเลียมและปิโตรเคมี จุฬาลงกรณ์มหาวิทยาลัย กล่าวว่า ทีมงานอยู่ระหว่างพัฒนาระบบนำส่งยาชา ให้เป็นสารขนาดนาโนเมตรใช้ทาผ่านผิวหนัง เหมาะใช้ในธุรกิจศัลยกรรมความงาม และวางยารักษาผู้ป่วยเด็ก

การให้ยาชาก่อนผ่าตัดมักฉีดเข้าสู่บริเวณที่ต้องการให้ยาออกฤทธิ์ชา โดยเฉพาะการทำศัลยกรรมบนใบหน้า ทำให้คนไข้รู้สึกเจ็บ แต่ยาชาที่บรรจุในแคปซูลนาโนไม่ต้องใช้เข็มฉีดเข้าสู่ร่างกาย เพียงแค่ใช้ยาเปิดผิวหนังเพื่อกระตุ้นผิวหนัง ก่อนทายาชาให้ซึมออกฤทธิ์บริเวณชั้นผิวหนังที่ต้องการ ยาชานาโนเป็นงานวิจัยใน โครงการพัฒนานาโนไคติน-ไคโตซาน เพื่อเป็นจุลยานต้นแบบของการนำส่งยาชาเฉพาะแห่ง

ทีมวิจัยเลือกใช้วัสดุไคโตซาน ซึ่งเป็นสารสกัดที่ได้จากเปลือกกุ้งและกระดองปู เป็นสารนำส่งยาโดยควบคุมโครงสร้างให้เป็นวัสดุนาโน และออกแบบทิศทางให้โมเลกุลจัดเรียงตัวและรวมกลุ่มเป็นทรงกลม โดยมีช่องว่างอยู่ตรงกลางสำหรับบรรจุยา ความคืบหน้าของโครงงานวิจัย ปัจจุบันโมเลกุลยาชาและสายโซ่นาโนโพลีเมอร์ สามารถยึดติดกันเพียง 5-10% ซึ่งประสิทธิภาพไม่เพียงพอที่จะออกฤทธิ์ชาได้เต็มที่ นักวิจัยต้องการการยึดติดอย่างน้อย 50% หรือยิ่งมากก็ยิ่งดี เพื่อให้ยาชามีประสิทธิภาพมากที่สุด นอกจากนี้นักวิจัยยังทดลองใช้สายโซ่ไคติน-ไคโตซานที่สั้นลง รวมถึงปรับปรุงวิธีบรรจุ ค้นหาหมู่สารโมเลกุลที่เป็นขั้วและไม่เป็นขั้วชนิดไม่เป็นสารพิษมาเติมลงไป รศ.ดร.สุวบุญ กล่าว

โครงการวิจัยระบบนำส่งยาชาแบบทายังอยู่ในขั้นตอนเริ่มต้นและจะต้องพัฒนาต่อเนื่องไปเรื่อยๆ กระทั่งทดสอบในสัตว์และคนตามลำดับ คาดว่าจะใช้เวลาอีก 1 ปี จึงจะพร้อมทดสอบในคน

>http://news.mjob.in.th/technology/cat8/news2602/

พลาสเตอร์ยานาโน

พลาสเตอร์ยานาโนรักษาแผลเบาหวาน
สำหรับผู้ป่วยเบาหวานแล้ว สิ่งที่พวกเขาหวาดกลัวมากที่สุดคือ แผลที่อาจเกิดขึ้นบริเวณเท้า ซึ่งรักาให้หายยาก และท้ายที่สุดต้องลงเอยที่การตัดเท้าทิ้ง พลาดเตอร์ยาที่ใช้ระบบส่งยาอนุภาคระดับนาโน สามารถช่วยให้แผลหายได้เร็วขึ้น นักวิจัยศูนย์นาโนเทคพัฒนาพลาสเตอร์ยานาโนที่บรรจุยาปฏิชีวนะไว้ภายใน หวังใช้ฆ่าเชื้อแบคทีเรียในแผลผู้ป่วยโรคเบาหวานที่หายยาก ชูจุดเด่นควบคุมการปลดปล่อยตัวยาได้ทั้งปริมาณและระยะเวลาตามต้องการ คาดอีกหนึ่งปีได้เห็นผลิตภัณฑ์ต้นแบบพร้อมผลิตเชิงพาณิชย์แน่นอน ดร.อุรชา รังสาดทอง นักวิจัยจากศูนย์นาโนเทคโนโลยีแห่งชาติ (นาโนเทค) เปิดเผยว่า โครงการวิจัยเรื่อง "การผลิตเส้นใยนาโนของโพลิเมอร์เพื่อพัฒนาระบบนำส่งยาปฏิชีวนะ" เป็นความร่วมมือกับศูนย์เทคโนโลยีโลหะและวัสดุแห่งชาติ (เอ็มเทค) และวิทยาลัยปิโตรเลียมและปิโตรเคมี จุฬาลงกรณ์มหาวิทยาลัย โดยมีวัตถุประสงค์เพื่อพัฒนาพลาสเตอร์ยาสำหรับใช้รักษาแผลที่หายยากของผู้ป่วยโรคเบาหวาน งานวิจัยชิ้นนี้ ได้รับงบประมาณสนับสนุนจากศูนย์นาโนเทคจำนวน 3 แสนบาท เป็นการดึงนาโนเทคโนโลยีมาช่วยในการนำส่งยาปฏิชีวนะเพื่อใช้รักษาแผลเฉพาะที่ ด้วยการใช้เทคนิคที่เรียกว่า อิเล็กโตรสปินนิ่ง (Electrospinning) หรือกระบวนการปั่นเส้นใยด้วยไฟฟ้าสถิต เพื่อให้ได้เส้นใยขนาดนาโนออกมา ซึ่งโพลิเมอร์ที่ทีมวิจัยเลือกมาใช้ในครั้งนี้ ได้แก่ พีวีเอ (Polyvinyl alcohol : PVA) ส่วนตัวยาปฏิชีวนะที่จะนำมาบรรจุลงในเส้นใย คือ ซีฟาเล็กซิน (Cephalexin) มีฤทธิ์ยับยั้งการเจริญเติบโตของแบคทีเรียที่เกิดการติดเชื้อบริเวณผิวหนังได้ดี จึงเหมาะกับผู้ป่วยโรคเบาหวาน เนื่องจากคนกลุ่มนี้เกิดเป็นแผลได้ง่าย เพราะมีระดับน้ำตาลในตัวปริมาณมาก เมื่อเป็นแผลแล้วก็จะหายช้า บางรายถึงขั้นต้องตัดอวัยวะที่ติดเชื้อทิ้งเพื่อป้องกันไม่ให้แผลเกิดการลุกลามก็มี สำหรับขั้นตอนการผลิต ดร.อุรชาอธิบายว่า ขั้นแรกต้องนำเอาตัวยามาละลายผสมกับโพลิเมอร์พีวีเอก่อน จากนั้นก็นำมาผ่านกระบวนการอิเล็กโตรสปินนิ่งให้ได้เส้นใยที่มีขนาดเล็กประมาณ 100-150 นาโนเมตร ซึ่งมียาปฏิชีวนะบรรจุไว้ภายใน จากขั้นตอนนี้ไปก็สามารถนำไปประยุกต์ทำเป็นแผ่นแปะหรือพลาสเตอร์ยาสำหรับใช้บริเวณผิวหนังได้ อย่างไรก็ตาม เทคโนโลยีในลักษณะนี้มีให้เห็นแล้วในต่างประเทศ เช่นในสหรัฐได้นำไปประยุกต์ใช้ในการผลิตเครื่องแบบทหาร มีคุณสมบัติช่วยลดการติดเชื้อและช่วยระบายเหงื่อและอากาศให้ดีขึ้น ปัจจุบันทีมวิจัยของไทยชุดนี้ สามารถควบคุมการปลดปล่อยตัวยาสู่บาดแผลได้แล้ว เนื่องจากแผ่นแปะซึ่งอยู่ในรูปของเส้นใยขนาดเล็กระดับนาโน ทำให้สามารถปลดปล่อยตัวยาออกมาได้ช้าและต่อเนื่อง ต่างจากการใส่ยาปกติที่จะไม่มีความต่อเนื่องในการส่งยาไปสู่บาดแผล อีกทั้งตัวยาก็จะออกมาเร็วเกินความต้องการ และจากการทดสอบในห้องปฏิบัติการพบว่า เส้นใยนาโนที่ผลิตขึ้นมานี้ไม่มีพิษต่อเซลล์ร่างกายแต่อย่างใด ดร.อุรชา บอกว่าเคล็ดลับในการควบคุมการปลดปล่อยยาของเส้นใยนั้น ขึ้นอยู่กับอัตราส่วนผสมระหว่างตัวยากับโพลิเมอร์ ขนาดของเส้นใย และชนิดของโพลิเมอร์ที่เลือกใช้ เช่น หากเลือกใช้โพลิเมอร์ที่ชอบน้ำ เวลาแปะลงไปที่ผิวหนัง เมื่อร่างกายมีเหงื่อเกิดขึ้น โพลิเมอร์ก็จะค่อยๆ ย่อยสลายและปล่อยตัวยาออกมาได้ "ตอนนี้กำลังทดสอบดูว่าต้องใช้ระยะ เวลานานแค่ไหนตัวยาถึงจะหมดแผ่น ซึ่งขณะนี้สามารถกำหนดระยะเวลาในการส่งยาจากแผ่นแปะไปยังแผลได้ประมาณ 2 วัน และขั้นต่อไปจะเป็นการพัฒนาให้อยู่ในรูปของพลาสเตอร์ยา คาดว่าหนึ่งปีก็น่าจะได้ผลิตภัณฑ์ต้นแบบออกมา หากสำเร็จก็จะเป็นทางเลือกใหม่ของระบบนำส่งยาทางผิวหนังได้" ดร.อุรชา กล่าว

>http://azooga.com/content_detail.php?cno=215

อิเล็กทรอนิกส์พิมพ์ได้(2)

อิเล็กทรอนิกส์พิมพ์ได้...โอกาสของไทยมาถึงแล้ว
Body: ดร.อดิสร เตือนตรานนท์
ศูนย์เทคโนโลยีอิเล็กทรอนิกส์และคอมพิวเตอร์แห่งชาติ
กรุงเทพธุรกิจ 2008 March, 14

อิเล็กทรอนิกส์แบบพลาสติก (Plastic Electronics) หรือที่เราอาจเรียกว่า E-plastic ทำจากวัสดุประเภทโพลิเมอร์แบบอินทรีย์ ซึ่งเป็นโมเลกุลขนาดเล็กที่สามารถนำไฟฟ้าได้และมีคุณสมบัติคล้ายวัสดุกึ่งตัวนำ นำมาสามารถสร้างเป็นวงจรทรานซิสเตอร์แบบฟิล์มบางบนวัสดุได้หลากหลายแบบรวมทั้งพลาสติก มันสามารถสร้างขึ้นด้วยเทคนิคการพิมพ์แบบอิงค์เจ็ต แต่แทนที่จะเป็นหมึกพิมพ์ เราก็ใช้หมึกโพลิเมอร์แทน หรือใช้การพิมพ์แบบซิลสกรีน คล้ายเวลาเราสกรีนเสื้อยืด แต่เรากำลังพิมพ์ลายที่เล็กและละเอียดในระดับไมโครเมตร หรือการพิมพ์แบบม้วนต่อม้วนเหมือนการพิมพ์หีบห่อบรรจุภัณฑ์เพื่อผลิตเป็นจำนวนมากในคราวเดียวกัน และอีกวิธีหนึ่งที่ดูเหมือนจะเป็นที่สนใจกันมากและยังอยู่ในขั้นการวิจัยคือการสร้างโดยการพิมพ์กดหรือ Stamping โดยใช้แม่พิมพ์ที่มีลวดลายนูนเพื่อพิมพ์ลวดลายโพลิเมอร์เป็นลายวงจรที่เล็กระดับนาโนเมตร เทคนิคนี้คล้ายการพิมพ์หมึกด้วยตรายาง ดังนั้นแน่นอนว่าข้อดีของอิเล็กทรอนิกส์แบบพิมพ์ได้หรือเรียกว่า Printed Electronics นี้ก็คือไม่จำเป็นต้องใช้เครื่องมือราคาแพงสำหรับการสร้างวงจรประเภทนี้ (การสร้างโรงงานผลิตชิพอิเล็กทรอนิกส์ที่ใช้อยู่ในปัจจุบันต้องลงทุนไม่ต่ำกว่า 40,000-50,000 ล้านบาทต่อโรงงาน) ล่าสุดข้อมูลจากบริษัทวิจัย Nanomarkets คาดการณ์ว่าตลาดผลิตภัณฑ์ที่ทำจากอิเล็กทรอนิกส์พลาสติกนี้จะเติบโตจากประมาณ 70 ล้านเหรียญสหรัฐฯ ไปเป็น 5,800 ล้านเหรียญ (ประมาณ 230,000 ล้านบาท) ภายในปี ค.ศ. 2009 ถึงแม้ตัวเลขนี้ยังไม่สูงมากนักเมื่อเทียบกับยอดขายชิพอิเล็กทรอนิกส์ต่อปีของบริษัทยักษ์ใหญ่อย่างอินเทล แต่ก็เป็นเทคโนโลยีที่บริษัทคู่แข่งอย่างโมโตโรล่าให้ความสำคัญและทุ่มวิจัยอยู่ในปัจจุบัน แน่นอนว่าความเร็วในการทำงานของชิพพลาสติกนี้ยังเทียบชั้นไม่ได้กับชิพแบบซิลิกอน จึงอาจจะไม่เหมาะกับการใช้เป็นชิพหน่วยประมวลผลหรือหน่วยความจำ แต่ในการใช้งาน
บางอย่างที่ความเร็วของวงจรไม่เป็นปัจจัยสำคัญอย่างเช่น จอแสดงผล หรือแผงเซลล์แสงอาทิตย์ หรือในวงจรเล็กๆ ไม่ซับซ้อนอย่างบัตรสมาร์ทการ์ด หรือชิพ RFID ซึ่งสามารถพิมพ์ลายวงจรบนหีบห่อได้โดยตรงเช่นเดียวกันกับการพิมพ์ตัวหนังสือบนกระดาษ ก็น่าจะมีโอกาสทางการตลาดอยู่ไม่น้อย ข้อมูลวิจัยจากบริษัท IDTechEX คาดการณ์ได้ว่าในอีกสิบปีข้างหน้า (ค.ศ. 2017) จะมีผลิตภัณฑ์อิเล็กทรอนิกส์ที่สร้างด้วยการพิมพ์เพิ่มสูงขึ้นเป็นร้อยละ 90 ดังนั้นจะเห็นได้ว่าอุตสาหกรรมการพิมพ์จะต้องเข้ามามีบทบาทที่สำคัญในการผลิตสินค้าอิเล็กทรอนิกส์ในอนาคตอย่างแน่นอน ดังนั้นมันเป็นโอกาสของเราแล้ว อุตสาหกรรมการพิมพ์ของไทยที่มีความก้าวหน้าเป็นอันดับต้นๆ ในเอเชีย ถ้าเข้าใจในผลกระทบของเทคโนโลยีอิเล็กทรอนิกส์พลาสติกก็จะต้องรีบปรับตัวและเตรียมตัวให้พร้อมรับกับการใช้เทคโนโลยีการพิมพ์ของตนกับการพิมพ์วัสดุโพลิเมอร์อื่นๆ ที่ไม่ใช่หมึกพิมพ์แต่เพียงอย่างเดียว ประเทศไทยจะได้ไม่ตกขบวนรถไฟ และใครจะเชื่อว่าในอนาคตไทยอาจจะเหมือนไต้หวันซึ่งเป็นผู้ผลิตชิปอิเล็กทรอนิกส์รายใหญ่ที่สุดในปัจจุบันก็ได้เพราะอิเล็กทรอนิกส์พิมพ์ได้นั่นเอง