PCL(1k)-PEG(3k)-BIO is a biodegradable amphiphilic block copolymer with hydrophobic block made of polycaprolactone (PCL) tethered to a hydrophilic PEG. It can self-assemble in aqueous media to form micelles and be used to prepare nanoparticles for drug encapsulation in nanomedicine/drug delivery. The biotin moiety is tethered to the PEG and can strongly bind to avidin/streptavidin. Reagent grade, for research purpose.