mPEG(1k)-PCL(2k)-COOH is a bioconjugation amphiphilic polymer. Reaction between carboxyl (COOH) and amine (NH2) occurs via activation with HATU/EDC to form a stable amide linkage. The copolymer can self-assemble in aqueous solution to form polymeric micelles. The core regions of the micelles are made of polycaprolactone (PCL) and can be used as hydrophobic drugs reservoir for targeted drug delivery. Reagent grade, for research purpose.