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Category : Nanomedicine

Nanomedicine – Wikipedia, the free encyclopedia

Nanomedicine is the medical application of nanotechnology.[1] Nanomedicine ranges from the medical applications of nanomaterials, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials (materials whose structure is on the scale of nanometers, i.e. billionths of a meter).

Nanomedicine research is receiving funding from the US National Institutes of Health. Of note is the funding in 2005 of 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.[2]

The biological and medical research communities have exploited the unique properties of nanomaterials for various applications (e.g., contrast agents for cell imaging and therapeutics for treating cancer). Terms such as biomedical nanotechnology, nanobiotechnology, and nanomedicine are used to describe this hybrid field. Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures. The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Thus far, the integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications, and drug delivery vehicles.

Nanomedicine seeks to deliver a valuable set of research tools and clinically useful devices in the near future.[3][4] The National Nanotechnology Initiative expects new commercial applications in the pharmaceutical industry that may include advanced drug delivery systems, new therapies, and in vivo imaging.[5] Neuro-electronic interfaces and other nanoelectronics-based sensors are another active goal of research. Further down the line, the speculative field of molecular nanotechnology believes that cell repair machines could revolutionize medicine and the medical field.

Nanomedicine is a large industry, with nanomedicine sales reaching $6.8 billion in 2004, and with over 200 companies and 38 products worldwide, a minimum of $3.8 billion in nanotechnology R&D is being invested every year.[6] As the nanomedicine industry continues to grow, it is expected to have a significant impact on the economy.

Two forms of nanomedicine that have already been tested in mice and are awaiting human trials that will be using gold nanoshells to help diagnose and treat cancer,[7] and using liposomes as vaccine adjuvants and as vehicles for drug transport.[8][9] Similarly, drug detoxification is also another application for nanomedicine which has shown promising results in rats.[10] A benefit of using nanoscale for medical technologies is that smaller devices are less invasive and can possibly be implanted inside the body, plus biochemical reaction times are much shorter. These devices are faster and more sensitive than typical drug delivery.[11] Advances in Lipid nanotechnology was also instrumental in engineering medical nanodevices and novel drug delivery systems as well as in developing sensing applications.[12]

Nanotechnology has provided the possibility of delivering drugs to specific cells using nanoparticles. The overall drug consumption and side-effects may be lowered significantly by depositing the active agent in the morbid region only and in no higher dose than needed. This highly selective approach would reduce costs and human suffering. An example can be found in dendrimers and nanoporous materials. Another example is to use block co-polymers, which form micelles for drug encapsulation.[13] They could hold small drug molecules transporting them to the desired location. Another vision is based on small electromechanical systems; nanoelectromechanical systems are being investigated for the active release of drugs. Some potentially important applications include cancer treatment with iron nanoparticles or gold shells. Targeted drug delivery is intended to reduce the side effects of drugs with concomitant decreases in consumption and treatment expenses. The increased efficiency of delivery results in overall societal benefit by reducing the amount of drug needed in an equipotent preparation of said therapy, and thus reduced cost to the consumer.

Nanomedical approaches to drug delivery center on developing nanoscale particles or molecules to improve drug 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. This can potentially be achieved by molecular targeting by nanoengineered devices.[14][15] It is all about targeting the molecules and delivering drugs with cell precision. More than $65 billion are wasted each year due to 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 methods of nanoengineered materials that are being developed might be effective in treating illnesses and diseases such as cancer. What nanoscientists will be able to achieve in the future is beyond current imagination. This might be accomplished by self assembled biocompatible nanodevices that will detect, evaluate, treat and report to the clinical doctor automatically.

Drug delivery systems, lipid- or polymer-based nanoparticles,[13] can be designed to improve the pharmacological and therapeutic properties of drugs.[16] The strength of drug delivery systems is their ability to alter the pharmacokinetics and biodistribution of the drug.[17][18] However, the pharmacokinetics and pharmacodynamics of nanomedicine is highly variable among different patients.[19] When designed to avoid the body’s defence mechanisms,[20] nanoparticles have beneficial 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 membranes and into cell cytoplasm. 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.[21] 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. Polymeric nano-particles are a competing technology to lipidic (based mainly on Phospholipids) nano-particles. There is an additional risk of toxicity associated with polymers not widely studied or understood. This toxicity could include (but not limited to) hepatotoxicity, nephrotoxicity etc. and can have long term impacts not easily evaluated in short term in-vivo clinical trials either in animals or humans. Since the degradation of polymers to either their monomers or other degradation products in the body cannot be accurately predicted (unclear metabolic pathway), this is a real risk, specially in medicines intended for long term patient use. Even if the toxicity is ignored, there is additional hepatic load of metabolism, again an area of concern for long term medication. The major advantages of polymers is stability, lower cost and predictable characterisation, so the formulation chemists prefer this. However, in the patient’s body this very stability (slow degradation) is a negative factor. Phospholipids on the other hand are membrane lipids (already present in the body and surrounding each cell), have a GRAS (Generally Recognised As Safe) status from FDA and are derived from natural sources without any complex chemistry involved. They are not metabolised but rather absorbed by the body and the degradation products are themselves nutrients (fats or micronutrients). It is greatly observed that[who?] nanoparticles are promising tools for the advancement of drug delivery, medical imaging, and as diagnostic sensors. However, the biodistribution of these nanoparticles is still imperfect due to the complex host’s reactions to nano- and microsized materials[14] and the difficulty in targeting specific organs in the body. Nevertheless, a lot of work is still ongoing to optimize and better understand the potential and limitations of nanoparticulate systems. For example, current research in the excretory systems of mice shows the ability of gold composites to selectively target certain organs based on their size and charge. These composites are encapsulated by a dendrimer and assigned a specific charge and size. Positively-charged gold nanoparticles were found to enter the kidneys while negatively-charged gold nanoparticles remained in the liver and spleen. It is suggested that the positive surface charge of the nanoparticle decreases the rate of opsonization of nanoparticles in the liver, thus affecting the excretory pathway. Even at a relatively small size of 5nm, though, these particles can become compartmentalized in the peripheral tissues, and will therefore accumulate in the body over time. While advancement of research proves that targeting and distribution can be augmented by nanoparticles, the dangers of nanotoxicity become an important next step in further understanding of their medical uses.[22]

Nanoparticles are also used to circumvent multidrug resistance (MDR) mechanisms.[23] Mechanisms of MDR include decreased uptake of drugs, reduced intracellular drug concentration by activation of the efflux transporters, modifications in cellular pathways by altering cell cycle checkpoints, increased metabolism of drugs, induced emergency response genes to impair apoptotic pathways and altered DNA repair mechanisms.

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Nanomedicine – Wikipedia, the free encyclopedia

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Nanomedicine, Volume 1: Basic Capabilities

Nanomedicine Book Site

1996-2013 Robert A. Freitas Jr. All Rights Reserved

Nanomedicine, Volume IIA: Biocompatibility by Robert A. Freitas Jr. is now available in hardcover for $99 + shipping. Click here to purchase the book at or click here for information or to purchase the book directly from Landes Bioscience.

Nanomedicine, Volume I: Basic Capabilities by Robert A. Freitas Jr. is now available in softcover for $89 + shipping. Click here for information or to purchase the book directly from Landes Bioscience.

About Nanomedicine (the field)

Molecular nanotechnology has been defined as the three-dimensional positional control of molecular structure to create materials and devices to molecular precision. The human body is comprised of molecules, hence the availability of molecular nanotechnology will permit dramatic progress in human medical services. More than just an extension of “molecular medicine,” nanomedicine will employ molecular machine systems to address medical problems, and will use molecular knowledge to maintain and improve human health at the molecular scale. Nanomedicine will have extraordinary and far-reaching implications for the medical profession, for the definition of disease, for the diagnosis and treatment of medical conditions including aging, and ultimately for the improvement and extension of natural human biological structure and function.

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Nanomedicine, Volume 1: Basic Capabilities

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Nanomedicine: Nanotechnology, Biology and Medicine – Official Site

The mission of Nanomedicine: Nanotechnology, Biology, and Medicine (Nanomedicine: NBM) is to promote the emerging interdisciplinary field of nanomedicine.

Nanomedicine: NBM is an international, peer-reviewed journal presenting novel, significant, and interdisciplinary theoretical and experimental results related to nanoscience and nanotechnology in the life sciences. Content includes basic, translational, and clinical research addressing diagnosis, treatment, monitoring, prediction, and prevention of diseases. In addition to bimonthly issues, the journal website ( also presents important nanomedicine-related information, such as future meetings, meeting summaries, funding opportunities, societal subjects, public health, and ethical issues of nanomedicine.

The potential scope of nanomedicine is broad, and we expect it to eventually involve all aspects of medicine. Sub-categories include synthesis, bioavailability, and biodistribution of nanomedicines; delivery, pharmacodynamics, and pharmacokinetics of nanomedicines; imaging; diagnostics; improved therapeutics; innovative biomaterials; interactions of nanomaterials with cells, tissues, and living organisms; regenerative medicine; public health; toxicology; point of care monitoring; nutrition; nanomedical devices; prosthetics; biomimetics; and bioinformatics.

Article formats include Communications, Original Articles, Reviews, Perspectives, Technical and Commercialization Notes, and Letters to the Editor. We invite authors to submit original manuscripts in these categories. The journal website ( also presents important nanomedicine-related information, such as future meetings, meeting summaries, funding opportunities, societal subjects, public health, and ethical issues of nanomedicine.

The mission of Nanomedicine: Nanotechnology, Biology, and Medicine (Nanomedicine: NBM) is to promote the emerging interdisciplinary field of nanomedicine.

Nanomedicine: NBM is an international, peer-reviewed…

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Nanomedicine: Nanotechnology, Biology and Medicine – Official Site

Recommendation and review posted by Alexandra Lee Anderson – Nanomedicine, bionanotechnology …

A lot of patients suffering from colon cancer might well present no symptoms or signs during the earliest stages of the condition. When symptoms do eventually present, they can be many and varied, and can very much depend upon the size of the affliction, how far it has spread and also its actual location. It might be that some symptoms that present are as a result of a condition other than cancer itself, ranging from irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and occasionally diverticulosis. Also, such problems as abdominal pain or swelling can be symptomatic of colon problems and may well require further investigation.

You may also notice that, upon going to the lavatory, you have some blood in your stools, and this can be a symptom of cancer. Of course, having black poop doesnt ultimately mean that cancer is present. It can, however, also be indicative of other conditions and problems. For example, the kind of bright red blood that you may see on your toilet tissue could be as a result of hemorrhoids or anal fissures. It should also be remembered that various food items can also result in red poop, and these include beetroot and red liquorice. Some medications can also be culprits, and some can also turn the stools black-including iron supplements. Irrespective, any sign of blood or change in your stools should prompt you to seek advice from your GP, as it is always best to be sure that it is not a sign of a more serious condition, and with any cancer,early detection and treatment is essential to a successful recovery.

You should also note-if you are currently concerned-any change in the regularity of your stools-including whether or not they are more thin or irregular than usual-especially over a period of several weeks. Also, be mindful if you have diarrhea for several days in a row or, conversely, constipation.

You might also experience pain in your lower abdomen-including a feeling of hardness. You may also experience persistent pain or discomfort in your abdominal region, and this can include wind and cramps. You may also get the sensation that, when evacuating your bowels, that the bowel doesnt empty fully. Another symptom that you might recognize is colored stool mainly black stool, but could be green stool too. Also, if you have an iron deficiency (or anemia), it may be an indication that there is bleeding in your colon. Also, as in most cases and types of cancer, you should seek medical advice immediately if you experience any sudden and unexpected or unexplained weight loss, as this is one of the principal red flags. Also be aware of more vague, seemingly incidental symptoms, such as fatigue. IF you have a couple of symptoms and also feel fatigued for days in a row inexplicably, then this is also another warning sign and you should seek medical advice. It is important not to panic, but just to be aware of what might be going on.

Remember, cases of colon cancer account for around 90% of all cases of intestinal cancers, and also account for more deaths every year of men and women from cancer. Early treatment is an absolute must.

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Nanomedicine Fact Sheet – National Human Genome Research …

Nanomedicine Overview

What if doctors had tiny tools that could search out and destroy the very first cancer cells of a tumor developing in the body? What if a cell’s broken part could be removed and replaced with a functioning miniature biological machine? Or what if molecule-sized pumps could be implanted in sick people to deliver life-saving medicines precisely where they are needed? These scenarios may sound unbelievable, but they are the ultimate goals of nanomedicine, a cutting-edge area of biomedical research that seeks to use nanotechnology tools to improve human health.

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A lot of things are small in today’s high-tech world of biomedical tools and therapies. But when it comes to nanomedicine, researchers are talking very, very small. A nanometer is one-billionth of a meter, too small even to be seen with a conventional lab microscope.

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Nanotechnology is the broad scientific field that encompasses nanomedicine. It involves the creation and use of materials and devices at the level of molecules and atoms, which are the parts of matter that combine to make molecules. Non-medical applications of nanotechnology now under development include tiny semiconductor chips made out of strings of single molecules and miniature computers made out of DNA, the material of our genes. Federally supported research in this area, conducted under the rubric of the National Nanotechnology Initiative, is ongoing with coordinated support from several agencies.

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For hundreds of years, microscopes have offered scientists a window inside cells. Researchers have used ever more powerful visualization tools to extensively categorize the parts and sub-parts of cells in vivid detail. Yet, what scientists have not been able to do is to exhaustively inventory cells, cell parts, and molecules within cell parts to answer questions such as, “How many?” “How big?” and “How fast?” Obtaining thorough, reliable measures of quantity is the vital first step of nanomedicine.

As part of the National Institutes of Health (NIH) Common Fund [], the NIH [] has established a handful of nanomedicine centers. These centers are staffed by a highly interdisciplinary scientific crew, including biologists, physicians, mathematicians, engineers and computer scientists. Research conducted over the first few years was spent gathering extensive information about how molecular machines are built.

Once researchers had catalogued the interactions between and within molecules, they turned toward using that information to manipulate those molecular machines to treat specific diseases. For example, one center is trying to return at least limited vision to people who have lost their sight. Others are trying to develop treatments for severe neurological disorders, cancer, and a serious blood disorder.

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Nanomedicine Fact Sheet – National Human Genome Research …

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