Abstract: Methoxypoly(ethylene glycol) Poly(caprolactone) (mPEG–PCL) copolymers are important synthetic biomedical materials with amphiphilicity, controlled biodegradability, and great biocompatibility. They have great potential application in the fields of nanotechnology, tissue engineering, pharmaceutics, and medicinal chemistry. mPEG–PCL copolymers are biodegradable, biocompatible, and semi-crystalline copolymers having a very low glass transition temperature. Due to their slow degradation, mPEG–PCLs are ideally suitable for long-term delivery extending over a period of more than one year. This has led to its application in the preparation of different delivery systems in the form of microspheres, nanospheres, micelles, polymersomes, nanogels, and implants. Various categories of drugs have been encapsulated in mPEG–PCL for targeted drug delivery and for controlled drug release. As a research acmes incurrent years, mPEG–PCL copolymers and their end group-derived nanoparticles can progress the drug loading of hydrophobic drugs, enhancement bioavailability, escape being engulfed by phagocytes, reduce the burst release, and augment the circulation time of drugs in blood. Furthermore, these nanoparticles can assemble in inflammation or target locations to improve drug efficiency and diminish toxicity because of their smaller particle size and modified surface. Recent

advances in mPEG–PCL block copolymer nanoparticles, counting the synthesis of mPEG–PCL and the preparation of mPEG–PCL nanoparticles, were discussed in this study, especially the drug release and adjustable characteristics of mPEG–PCL nanoparticles and their application in pharmaceutical preparations.

Keywords: mPEG–PCL; block copolymer; nanoparticles; drug delivery system