Regardless of their specialty, clinicians will encounter patients who are affected by diabetes mellitus, infection and wound healing issues. Therefore, the emerging, evolving science of nanomedicine and how this technology could positively enhance patient outcomes would be of great interest to all physicians including DPMs.
The current literature has reported and recognized the many possibilities and applications for nanotechnology. The impact of nanotechnology on medicine is growing with each passing day. The medical applications for nanotechnology are enormous and could give medicine, including the treatment of diabetes, an entirely new outlook.
Accordingly, let us take a closer look at the pharmacological aspects for nanomedicine as a therapeutic approach as it may apply to podiatric medicine and diabetes.
Nanomedicine utilizes components as tiny as 1/80,000th of the diameter of a human hair. At the scale of 1 nanometer (or 10 times the diameter of a hydrogen atom), materials and devices can interact with cells and biological molecules in a unique way.1 The applications of nanomedicine include the detection of molecules such as proteins or DNA, imaging enhancers and targeting specific tissues to deliver therapeutic agents.1
Pharmaceutical companies are developing targeted drug delivery systems via a combination of nanotechnology and medications that already exist.
Bottomley defines nanotechnology, as it applies to the pharmaceutical industry, as the generation of therapeutically relevant matter between 1 and 100 nm.2 Delivery vehicles with nanometer dimensions can include complex functions such as controlled release and tissue targeting delivery. The nanoparticles used in tissue targeting delivery contain therapeutic molecules, which can be released at a desired time and location.1
When it comes to improved drug delivery, nanotechology can associate drug nanoparticles with a carrier like plasma albumin to improve organ targeting or encapsulate the active material in liposomes. Each process improves medication targeting by enhancing the drug compound’s half-life.2 Drug targeting via nanotechnology can also decrease general drug-induced toxicities by limiting systemic exposure.2
What The Emerging Research Reveals About Nanomedicine
Although the science of nanomedicine is still in its infancy, it has major potential applications in treating diabetes as detailed by Martinac and Metelko.3 These authors describe the Ferrari and Desai implantable nanomedical device, which contains pancreatic beta cells from animals.3,4 The intention of this device is the temporary restoration of the body’s delicate glucose control feedback loop without the need of powerful immunosuppressants.4
Another application of nanotechnology is known as the SmartCell, which was originally developed at the Massachusetts Institute of Technology. When glucose rises in the bloodstream, the structure of the SmartCell will be eaten away. This breakdown of the SmartCell’s protein matrix facilitates the release of insulin.5
Finally, Pickup and colleagues report several nanomedicine advancements and their potential in diabetes research and practice.6 These include the use of non-invasive glucose monitoring via implanted nanosensors. The key techniques include fluorescence resonance energy transfer (FRET) and fluorescence lifetime sensing as well as new nano-encapsulation technologies for sensors such as layer-by-layer (LBL) films.6 Researchers also note that nano-encapsulation technology might achieve better insulin delivery in diabetes via improved islet encapsulation and oral insulin formulations.6
Yacoby and Benhar recently reviewed nine clinical studies of nanomedicine-oriented applications of antiseptics, disinfectants and antibacterial therapeutics.7 The first six studies described synthetic nanomaterials with antibacterial activity. The last three studies involved bio-inspired antibacterial nanomedicines, applications based on biological substances.
In a study intended to develop a therapeutic approach, researchers showed that targeting of phage nanomedicines via specific antibodies to receptors on cancer cell membranes results in endocytosis, intracellular degradation and drug release.8,9 This results in growth inhibition of the target cells in vitro with a potentiation factor of > 1,000 over the corresponding free drugs, proving that nanomedicine technology offers significant advantages over traditional medication delivery.
Hromadka and co-workers summarize nanofibers, which mimic collagen fibrils in the extracellular matrix.9 These nanofibers can be created from a host of natural and synthetic compounds that may be beneficial to treating burn wounds. As the authors note, nanofiber technology can dramatically accelerate the development of innovative dressing materials for wound healing. Collagen nanofiber mats have shown increased wound healing properties. In addition, nanofibers have a significant potential in targeted drug delivery. This includes the delivery of antibiotics, analgesics and growth factors that will promote burn healing, decrease wound infection and improve scarring.9
A recent review focused on the results of in vivo studies of polyacrylate nanoparticle emulsions for topical and systemic applications.10 The authors conclude that emulsions containing polyacrylate nanoparticles may demonstrate potential in treating skin and systemic infections.
What Does The Future Hold For Nanotechnology?
Most scientists believe nanotechnology will start seriously influencing medicine around the year 2020.4,11 Nanotechnology has revolutionized many research areas. Orthopedic research is currently looking at the use of nanotechnology to address associated orthopedic implant design and tissue regeneration.12
The success of orthopedic implants and tissue engineered constructs greatly depends on the biocompatibility of the material.12 Several techniques for patterning implant surfaces and efficiently constructing scaffolds for tissue engineering have emerged. Some of these techniques include lithography, polymer demixing, phase separation chemical etching, electrospinning and molecular self-assembly.12
Various tissue engineering strategies have adopted composite scaffold approaches to mimic bone more closely because it is considered a natural composite of nanohydroxyapatite.12 Nanoparticles including calcium triphosphate, bioactive glass, hydroxyapatite, synthetic chitin, chitosan and biodegradable polymers have been fabricated into porous three-dimensional scaffolds for bone repair and regeneration purposes.12,13 This approach not only allows for mimicking bone in composition but the incorporation of nanoceramics enhances the material’s mechanical strength and nanopographic features.12
The utilization of polymer ceramic matrices containing single or multi-walled carbon nanotubes offers high tensile strength, high flexibility and low density that can be exploited to develop more successful orthopedic implant materials.12,14 With the advent of nanofabrication techniques, scientists may fabricate several biomaterials into nanostructures that simulate the native hierarchical structure of the bone.
The science of nanotechnology is already an integral part our daily lives in computers and the cell phone industry. Although the science is still in its infancy, it is a natural progression. Healthcare providers have embraced nanotechnology in an attempt to better diagnose and treat pathological processes and diseases.
There has been a great deal of work specific to nanotechnology for disease states such as diabetes mellitus, infection processes, wound healing applications as well as orthopedic applications. Podiatric physicians should become familiar with nanotechnology and the potential implications this science may have within the specialty of podiatric medicine.
Dr. Smith is in private practice at Shoe String Podiatry in Ormond Beach, Fla.
Dr. Steinberg is an Assistant Professor in the Department of Plastic Surgery at the Georgetown University School of Medicine in Washington, D.C. Dr. Steinberg is a Fellow of the American College of Foot and Ankle Surgeons.
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2. Bottomley K. Nanotechnology for drug delivery: a validated technology? PharmaDeals Review. 2007; 2 1-3.
3. Martinac K, Metelko Z. Nanotechnology and diabetes. Diabetologia Croatica 2005; 34(4):105-110.
4. Fritas RA. Current status of nanomedicine and medical nanorobotics. http://www.nanomedicine.com /Papers/NMRevMar05.pdf accessed June 22, 2009
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