PCL(10k)-mPEG(1k) is a biocompatible amphiphilic block copolymer with a polycaprolactone (PCL) hydrophobic segment attached to a PEG hydrophilic block. The polymer can self-assemble in water to form micelles with PCL as core and PEG as shell. The core of the micelles can serve as reservoir for hydrophobic drugs in drug delivery system. Reagent grade, for research purpose.