PCL(3k)-PEG(5k)-SPDP contains two distinct polymers, a hydrophobic polycaprolactone (PCL) block and a hydrophilic PEG block. The polymer can form micelles in water with PCL core and PEG shell formation. The core can be used to entrap hydrophobic drugs for controlled release drug delivery. SPDP moiety is reactive with thiol. Reagent grade, for research purpose.