PEGylation, the Glorious Past, Present Dilemma and Future

Abstract

Polyethene glycol (PEG), with first application approved in 1990, is a widely used polymer in the modification of nanometer level drug particles until now due to its outstanding ability to give nanoparticle the “stealth” property in drug delivery in circulation system thus enhancing the half-life. Therefore, this paper aimed to deconstruction the mechanism how PEG works on liposome with a present example by literature review on recent and previously published papers. Except the advantages of PEG in drug delivery, accelerated blood clearance (ABC) phenomenon as a massive problem in PEG application is been discovering by other researchers. This paper collected the relevant papers about the recent discovery on ABC phenomenon about how the immune system is stimulated to produce anti-PEG IgM which causes the rapid clearance of PEGylated nanoparticle in second dosing, and some alternative polymers are selected among the alternatives by the capability to replace PEG and preserving the “stealth” ability. However, the fact is that the alternatives have their disadvantages to some extent cannot perfectly replace PEG without any side effects.