Nanotechnology seems to be a buzz word in numerous fields of science and engineering.

Generally in science, nanotechnology/nanoscience is well associated with drug delivery with nanotechnology being described as a novel and practical application of scientific knowledge. The aim of any research within this field of drug delivery, is to prevent, control, treat infections and/or diseases which can be delivered more effectively to the target site for enhanced efficacy and reduced side-effects.

There are a few polymers which can be used to encapsulate the drug of interest which are FDA approved. Commonly poly (lactic-co-glycolic acid) (PLGA) is used as it is hydrolysed to its monomers, lactic acid and glycolic acid which are readily metabolised in the body via the Krebs cycle. Hydrophobicity of the hydrophobic PLGA polymer can be increased to aid solubility and membrane transfer by the addition of polyethylene glycol (PEG). Specific target delivery can be achieved by surface modification by attaching the receptor or ligand to the surface of PEG.

There have been many examples of drug delivery which are in development or clinical use. Nanoparticles have shown tremendous impact in treating various cancers such as ovarian, skin and breast. Doxorubicin was the first nanoparticle used in cancer chemotherapy, this drug was encapsulated in anionic liposomes which showed accumulation in tumours. Currently, there are two liposomal formulations of doxorubicin. Doxil, which is a polyethylene glycol coated liposome which is used to treat AIDS-related cancers and is FDA approved. Myocet is the non-peglated version which has fewer side effects than Doxil and is approved in Europe to treat breast cancer.

There has been increasing interest into delivering oligonucleotides using nanoparticles. A study showed that attaching multiple stands of antisense DNA to gold nanoparticles were much more effective than the antisense DNA alone. The bound antisense DNA attached to gold nanoparticles provided improved stability, reduced degradation and were readily absorbed by cells.