PCL(10k)-PEG(5k)-BIO can self-assemble in water to form polymeric micelles/nanoparticles. They consists of hydrophobic core-forming block polycaprolactone (PCL) and hydrophilic shell-forming PEG block. This biodegradable polymer can be used to encapsulate drugs in nanomedicine or drug delivery system. It can be used for biotinylation due to the strong binding between biotin and avidin/streptavidin. Reagent grade, for research purpose.