Nanomedicine is the application of nanotechnology to the field of medicine by the use of a material at the nanometer scale. The most common application of nanomedicine involves employing nanoparticles to enhance the action of drugs in treatment.
Research in the field has created targeted drug delivery, new methods of diagnosis and imaging as well as the production of hybrid treatments. The benefits of nanomedicine can be divided into the advantages produced by nanotherapeutics, nanodiagnostics and nanotheranostics.
Benefits of Nanotherapeutics
Many current applications of nanomedicine are providing improvements to drug delivery for therapy. For drugs that are only mildly water-soluble there can be difficulties in terms of absorption to the site of need.
Nanotechnology has been applied to increase absorbability. Nanomedicine is also applicable for drugs that are absorbed too quickly and removed from the body as waste before treatment can be affective. Nanomedicine can increase the time period in which a drug remains active in the body.
It is important that drugs for treating cancers are specifically targeted to avoid damage to the surrounding healthy cells. Along with the ability to improve drug target specificity, nanotherapeutics can also lead to a reduction in drug volume, avoiding the problem of accumulation in healthy tissue.
A common characteristic of solid tumors is leaky blood vessels. Nanomedicines, due to their size, preferentially accumulate in tissue through leakage in the blood vessels. They are then retained within the tissue because of effective lymphatic drainage being absent in solid tumors.
This important mechanism for nanodrug delivery is called enhanced permeability and retention (EPR) and is an example of passive drug targeting. The accumulation effect is also produced in inflammatory diseases such as rheumatoid arthritis because blood vessel leakage is a common characteristic of inflamed tissue. Nanotherapeutics provides site specific drug delivery for treatment of inflammatory diseases through the same accumulation effect as found in solid tumors.
Benefits of Nanodiagnostics
Nanotechnology has also been applied to diagnostics because of the distinct optical, magnetic and structural properties of nanomaterials which make them suitable for diagnostic imaging and tumor detection.
Nanoparticles have greater adaptable optical and magnetic features than larger materials because of modified quantum mechanics at the nanoscale. Therefore, the simple alteration of nanoparticle size can calibrate properties such as color.
An important aspect of medical diagnostics is the detection and identification of the substance used for diagnostic results. Because various colors can be produced by changing the size of the nanoparticle, this is particularly useful for the color coding and labeling of materials used during diagnostic tests.
Diagnostic imaging is defined as non-invasive methods for identifying and monitoring disease in the body. Nanotechnology is being used to enhance current medical imaging methods such as nuclear magnetic resonance spectroscopy for MRI scans.
The images produced are based on exploiting the magnetic properties of atomic nuclei. To produce electromagnetic excitation at the nanoscale, a new method of magnetic field manipulation has been produced via radio-frequency pulses emitted at a micro-second timescale.
This has allowed for the application of nuclear magnetic resonance spectroscopy to the nano scale and the generation of more detailed imaging.
Benefits of Nanotheranostics
Theranostics relate to the combination of diagnostics with therapy. Nanotechnology is particularly suitable for the provision of material with both imaging and drug agents that can produce practical theranostic tools.
An advantage of this technique is that it provides the capacity for personalized medicine. For cancer patients, this involves the amalgamation of imaging agents with chemo-therapeutic drugs. It should be noted that in terms of the diagnostic element of theranostics, for the majority of cases a diagnosis has already been performed in order to choose the most appropriate chemo-therapeutic drug.
The imaging agents are most often utilized for predicting patient response and for monitoring treatment efficacy over time. Imaging agents can also be used for predicting side effects in certain patients by providing data of potential non-target accumulation sites in healthy tissue.
Shelley Farrar Stoakes, MSc, BSc
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- New research offers breakthrough in nanotechnology, University of Sheffield. https://www.sheffield.ac.uk/news/nr/nanotechnology-nuclear-magnetic-resonance-1.174327