Abstract
Over the past few decades, nanoparticles have been attracting significant attention of researches in chemical, biomedical, pharmaceutical sciences, due to their unique physicochemical properties.This includes ultra small size, large surface area, good biocompatibility and high reactivity.In particular, nanoparticles are promising for pharmaceutical and biomedical fields, as they have been applied as drug carriers and diagnostic tools.However, nanoparticles can be easily detected and cleared out by the mononuclear phagocyte system before delivering the drug to the target site.One of the most widely applied approaches to prolong circulation of nanoparticles is to modify their surfaces with polyethylene glycol (PEG).This paper describes how PEGylation occurs, as well as application of various PEGylated nanoparticles in drug delivery.