PCL(2k)-PEG(3k)-NHS is an amine reactive amphiphile polymer for conjugation. Upon dispersion in aqueous solution, polymeric micelles are formed with polycaprolactone (PCL) hydrophobic core and PEG hydrophilic shell. The core regions can be used to entrap hydrophobic drugs. The polymer is biodegradable via hydrolytic attack on the ester bonds. Reagent grade, for research purpose.