Nanomedicine: current status and future prospects

Abstract

Applications of nanotechnology for treatment, diagnosis, monitoring, and control of biological systems has recently been referred to as "nanomedicine" by the National Institutes of Health. Research into the rational delivery and targeting of pharmaceutical, therapeutic, and diagnostic agents is at the forefront of projects in nanomedicine. These involve the identification of precise targets (cells and receptors) related to specific clinical conditions and choice of the appropriate nanocarriers to achieve the required responses while minimizing the side effects. Mononuclear phagocytes, dendritic cells, endothelial cells, and cancers (tumor cells, as well as tumor neovasculature) are key targets. Today, nanotechnology and nanoscience approaches to particle design and formulation are beginning to expand the market for many drugs and are forming the basis for a highly profitable niche within the industry, but some predicted benefits are hyped. This article will highlight rational approaches in design and surface engineering of nanoscale vehicles and entities for site-specific drug delivery and medical imaging after parenteral administration. Potential pitfalls or side effects associated with nanoparticles are also discussed.

Transferrin-functionalized nanoparticles lose their targeting capabilities when a biomolecule corona adsorbs on the surface

“…These efforts have met with varying success [5][6][7] , and it is not always possible to fully explain the different outcomes. Likely, there are several reasons for this 2,9,11,12 , but certainly there remains a lack of detailed mechanistic information on the link between nanoparticle surface and biological interactions.…”

“…While it is clear that nanoparticle size and shape are key factors for uptake [15][16][17] , current targeting strategies also involve conjugation of biofunctional moieties to nanoparticles in an effort to determine the biological outcomes 1,2,9,12,[18][19][20] . In some cases this seems successful, 3 but in others less so (for example targeting moieties can hinder biological barrier penetration 8,11 ).…”

Formation and Characterization of Polyglutamate Core−Shell Microspheres

“…5 In all cases, these protein microspheres are comparable in size to an erythrocyte (i.e., several microns in diameter) and, thus, trapped in the blood pool. The ability to make smaller submicron protein microspheres that would be capable of escaping into poorly developed vasculature, such as found in tumors, 6 has not been previously achieved.…”

Exploiting nanotechnology to target cancer

“…Iron oxide nanocrystals ( Figure 2) with superparamagnetic properties have been used as contrast agents in magnetic resonance imaging (MRI) as they cause changes in the spin -spin relaxation times of the neighbouring water molecules (Moghimi et al, 2005). In an interesting study, highly lymphotropic superparamagnetic nanoparticles, which gain access to lymph nodes by means of interstitial -lymphatic fluid transport, were used in conjunction with high-resolution MRI to reveal small and otherwise undetectable lymph-node metastases in patients with prostate cancer (Harisinghani et al, 2003).…”

“…One of the earliest applications of nanotechnology in medicine was the use of liposomes in the nanoscale range to deliver chemotherapy payloads to the tumour (Moghimi et al, 2005). Liposomal formulations of doxorubicin are now approved for use in Kaposi sarcoma, breast cancer and refractory ovarian cancer.…”