>Nanomedicine

Nanomedicine in 21 th century:

แนวโน้ม การประยุกต์ใช้นาโนเทคโนโลยี่ในทางการแพทย์ ในศตวรรษหน้า

1. Nanodiagnostics
Molecular diagnostics
Nanoendoscopy
Nanoimaging

2. Nanotechnology-based Drugs
Drugs with improved methods of delivery

3. Regenerative Medicine
Tissue engineering with nanotechnology

4. Transplantation medicine
Exosomes from donor dendritic cells for drug-free organ transplants.

5. nanorobotic Treatments
Vascular sugery by nanorobotics introduced into thevascula system.
Nanorobots for detection and destruction of cancer.

6. Implants
Bioimportable sensors that bridge the gap between electronic and neurological circuitry.
Durable rejection-resistant artificial tissue and organs.
Implantations of nanocoated stents in coronary arteries to elute drugs and to prevent recclusion.
Implantation of nanopumps for drug delivery.

7. Minimally Invasive Surgery using catheters
Miniaturized nanosensors implanted in catheters to provide real-time data to surgeons
Nanosurgery by integration of nanoparticles and external energy

ตัวอย่าง ความก้าวหน้าทางการแพทย์ยุคนาโนเทคโนโลยี่ ความท้าทายอันยิ่งใหญ่

1.การปรับปรุงการถ่ายภาพเพื่อการวินิจฉัยโรค(Imaging)
ความก้าวหน้าทางนาโนเทคโนโลยี่ ที่นำสารเพิ่มความชัดภาพที่พัฒนาขึ้นมาใหม่ มาใช้เพิ่มความชัดภาพ(Imaging) ช่วยให้ตรวจจับปัญหาได้ตั้งแต่ขั้นเริ่มต้น ช่วยให้เห็นการเปลี่ยนแปลง(เนื้องอก)ตั้งแต่มีขนาดเพียงไม่กี่เซลล์(ระดับนาโน)

2.นาโนสู้มะเร็งร้าย แนวทางใหม่ในการรักษาและส่งผ่านยา(Drug delivery)
อนุภาคเปลือกนาโนทอง ถูกนำมาใช้ร่วมกับการฉายแสงอินฟราเรด เพื่อทำลายเซลล์มะเร็ง และใช้นำส่งผ่านยาไปยังเซลล์มะเร็งอย่างเฉพาะเจาะจง

3.การค้นพบวัสดุนาโนที่ช่วยให้การปลูกถ่ายดีกว่าเดิม(Tissue Engineering)
งานวิจัยระดัยนาโนทำให้นำวัสดุที่มีคุณสมบัติพิเศษช่วยเพิ่มความทนทานของชิ้นส่วนและความเข้ากันได้ทางชีวภาพ เช่นสะโพกเทียมเคลือบด้วยอนุภาคนาโน อาจยึดกับกระดูกรอบข้างได้ดีกว่าปกติ

4.แถบป้ายแม่เหล็ก(fluorescent Label) สำหรับการทดสอบทางชีวการแพทย์
การตรวจวินิจฉัยการเกิดโรค โดยประยุกติใช้อนุภาคนาโนที่ถูกติดฉลากกับแอนติบอดี้ซึ่งจับตัวกับโมเลกุลเป้าหมาย สามารถตรวจวัดสัญญาณแม่เหล็ได้ ทำให้เราอ่านผลการตรวจวัดได้โดยไม่ต้องนำตัวอย่างไปล้างแยกออกจากตัวตรวจวัดที่ไม่ได้จับกับเป้หมาย

5.บาร์โค้ดนาโน
เม็ดกลมลาเทกซ์ บรรจุอนุภาคสารกึ่งตัวนำระดับนาโนหลากหลายสี” หมุดควอนตัม” (Quntum Dot) มีสักยภาพในการเป็นฉลากเฉพาะตัวสำหรับวัดที่แตกต่างกัน เมื่อฉายแสงเม็ดกลมแต่ละชนิด๖ซึ่งรวมตัวตรวจวัดที่เชื่อมกับมันจะเปล่งแสงแตกต่างกันออกมา เป้ฯแสงที่มีลักษระเฉพาะสามารถแยกออกเป็นสเป็ปตรัมแถบสีค้ายบาร์โค้ด

6.DNA Chip บนคานฉลาด

7.เดนไดรเมอร์อินทรีย์(Organic Dendrimer)

8.ไมโครฟลูอิดิค (Microfluidics) ช่วยเพิ่มประสิทธิภาพงานวิจัยทางชีวการแพทย์

Source:
1.นาโนเทคดนโลยี่เพื่อรักษามะเร็ง
> http://nano.cancer.gov
2.หมุดควอนตัม
> http://www.qdot.com
3.งานวิจัยโฟโตนิกส์นาโนของนาโอมิ ฮาลาส
> http://www.ece.rice.edu/~halas/
4.นาโนเทคโลยี่ของ DNA:
> http://seemanlab4.chem.nyu.edu/

5  Nanoparticulate Drug Delivery Systems By: Deepak Thassu,Michel Deleers,Vashwant Pathak

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ROLE OF NANOBIOTECHNOLOGY-BASED DRUG DELIVERY IN DEVELOPMENT OF NANOMEDICINE

Several nanoparticle-based technologies for drug delivery are described in various chapters of this book. This section will briefly describe the relevance of these tech- nologies for practical human therapeutics.

An important clinical aspect of nanoparticle-based therapeutics is targeted drug delivery. When nanoparticles are used in the treatment of cancer, their power- ful targeting ability and potential for large cytotoxic payload dramatically enhance the efficacy of conventional pharmaceuticals as well as novel therapeutic approaches, such as gene therapy, radioimmunotherapy, and photodynamic therapy.

There are particular advantages of drug delivery for the treatment of various diseases by nanoscale devices. There are several requirements for developing a device small enough to efficiently leave the vasculature and enter cells to perform multiple, smart tasks. However, the major requirement involves size. Vascular pores limit egress of therapeutics to materials less than approximately 50 nm in diameter, and cells will not internalize materials much greater than 100 nm. As a result, the only currently available technology that fulfills these criteria consists of synthetic nanodevices. These are designed, synthetic materials with structures less than 100 nm in size. Unlike fictional mechanical nanomachines, based on devices that have been “shrunken” to nanometer dimensions, several true nanomolecular structures have now been synthesized and applied to drug delivery, gene transfer, antimicrobial therapeutics, and immunodiagnostics.

Nanoparticles are important for delivering drugs intravenously so that they can pass safely through the body’s smallest blood vessels, for increasing the surface area of a drug so that it will dissolve more rapidly, and for delivering drugs via inhalation. Porosity is important for entrapping gases in nanoparticles, for control- ling the release rate of the drug, and for targeting drugs to specific regions. Owing to their small size, lipid nanocapsules might be promising for an injectable as well as for an oral drug-delivery system, providing sufficient drug solubility to avoid embolization in blood after intravenous injection as well as a positive effect of drug absorption after oral administration. A drug-delivery system for intravenous admin- istration of ibuprofen has been developed which exhibits sustained-release proper- ties by either oral or intravenous route and may be useful for the treatment of postoperative pain.

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NANOMEDICINE

Besides nanoparticles, various nanotechnologies and other nanomaterials that are currently under investigation in medical research and diagnostics will soon find a practical application in practice of medicine. Nanobiotechnologies are being used to create and study models of human disease, particularly immune disorders. Introduction of nanobiotechnologies in medicine will not create a separate branch of medicine but simply implies improvement of diagnosis as well as therapy and can be referred to as nanomedicine. This broad term covers various therapeutic areas including treatments that may require surgical intervention.

Clinical Nanodiagnostics

Application of nanotechnology in molecular diagnostics will have a tremendous impact on the practice of medicine. Biosensor systems based on nanotechnology could detect emerging disease in the body at a stage that may be curable. This is extremely important in management of infections and cancer. Some of the body functions and responses to treatment will be monitored without cumbersome labo- ratory equipment. Some examples are a radiotransmitter small enough to put into a cell and acoustical devices to measure and record the noise a heart makes. Nanodiagnostics will also be integrated with nanotherapeutics.

Nanoendoscopy

Endoscopic microcapsules that can be ingested and precisely positioned are being developed. A control system will enable the capsule to attach to the digestive tract

and move within it. Precisely positioned microcapsules would allow physicians to view any part of the inside lining of the digestive tract in detail, resulting in more efficient, accurate, and less invasive diagnoses. In addition, these capsules could be modified to include treatment mechanisms as well, such as the release of a drug or chemical near a diseased area.

PillCam? capsule (Given Imaging Ltd., Yoqneam, Israel), an endoscope to visualize small intestine abnormalities, was approved in 2001. Other companies are now producing ingestible capsules for this purpose. The patient ingests the capsule, which contains a tiny camera, and intestinal peristalsis propels the capsule for approximately eight hours. During this time, the camera snaps the pictures and images that are transmitted to a data recorder worn by the patient. The physicians can review the images later on to make the diagnosis, but some abnormalities may be missed as this method has only a 50% success rate in detection of diseases. Controlling the positioning and movement on a nanoscale will greatly improve the accuracy of this method. Similar nanorobots are under development for other parts of the body.

Nanobiotechnology for Developing Stem-Cell-Based Therapies

Stem-cell-based therapies are one of the most promising areas of development in human therapeutics. Nanobiotechnology can be applied to delivery of gene therapy using geneti-cally modified stem cells and further applied in tracking stem cells introduced into the human body.

Nanofibrous scaffolds are being developed for stem cells to mimic the nano- meter-scale fibers normally found in that matrix (13). They are being used to grow stem cells derived from adipose tissue. They can conceivably be used for tissue repair.

Application of Nanobiotechnology in Various Therapeutic Areas Nanobiotechnology has been applied in almost every area of human healthcare. Some examples are given of applications in important therapeutic areas: cancer, neurological disorders, cardiovascular diseases, and infections.

Oncology

Disorders of the Central Nervous System

Cardiovascular Diseases

Infections

ROLE OF NANOBIOTECHNOLOGY IN THE DEVELOPMENT OF PERSONALIZED MEDICINE

Personalized medicine simply means the prescription of specific therapeutics best suited for an individual. It is usually based on pharmacogenetic, pharmacogenomic, and pharmacoproteomic information, but other individual variations in patients are also taken into consideration . Personalized medicine is beginning to be recognized and is expected to become a part of medical practice within the next decade. Molecular diagnostics is an important component of personalized medi- cine. Improvement of diagnostics by nanotechnology has a positive impact on personalized medicine. Nanotechnology has potential advantages in applications in point-of-care diagnosis, for example, on patient’s bedside or the outpatient clinic, self-diagnostics for use in the home, and integration of diagnostics with therapeu- tics. All of these will facilitate the development of personalized medicines. Cancer is a good example of advantages of personalized management. In cases of cancer, the variation in behavior of cancer of the same histological type from one patient to another is also taken into consideration. Personalization of cancer therapies is based on a better understanding of the disease at the molecular level, and nanotechnology will play an important role in this area.

CONCLUDING REMARKS AND FUTURE PROSPECTS

Disease and other disturbances of function are caused largely by damage at the molecular and cellular level, but current surgical tools are large and crude. Even a fine scalpel is a weapon more suited to tear and injure than heal and cure. It would make more sense to operate at the cell level to correct the cause of disease, rather than chop off large lesions as a result of the disturbances at cell level.

Nanotechnology will enable construction of computer-controlled molecular tools that are much smaller than a human cell and built with the accuracy and preci- sion of drug molecules. Such tools will be used for interventions in a refined and controlled manner at the cellular and molecular levels. They could remove obstruc- tions in the circulatory system, kill cancer cells, or take over the function of subcel- lular organelles. Instead of transplanting artificial hearts, a surgeon of the future would be transplanting artificial mitochondrion.

Nanotechnology will also provide devices to examine tissue in minute detail. Biosensors that are smaller than a cell would give us an inside look at cellular func- tion. Tissues could be analyzed down to the molecular level, giving a completely detailed “snapshot” of cellular, subcellular, and molecular activities. Such a detailed diagnosis would guide the appropriate treatment.

An increasing use of nanobiotechnology by the pharmaceutical and biotech- nology industries is anticipated. Nanotechnology will be applied at all stages of drug development ? from formulations for optimal delivery to diagnostic applica- tions in clinical trials.

It is expected that within the next few years, we will have a better understand- ing of how to coat or chemically alter nanoparticles to reduce their toxicity to the body, which will allow us to broaden their use for disease diagnosis and for drug delivery. Biomedical applications are likely to be some of the earliest. The first clinical trials are anticipated for cancer therapy

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