PCL(10k)-PEG(1k)-BIO is a block copolymer containing biotin which can bind strongly to avidin or streptavidin. The hydrophobic block is made of polycaprolactone while the hydrophilic block is made of PEG. Upon dispersion in water, the amphiphilic polymer can self-assemble to form micelles which can be used to prepare drug nanocarrier for sustained drug delivery. Reagent grade, for research purpose.