PCL(5k)-PEG(1k)-BIO is a biotinylation amphiphilic copolymer which can bind strongly to avidin/streptavidin. The amphiphile polymer has hydrophobic block polycaprolactone (PCL) chemically attached to hydrophilic PEG block. The polymer can be used to encapsulate drugs or therapeutic agents in drug delivery system. The polymer is biodegradable via hydrolysis on the ester bonds. Reagent grade, for research purpose.