PCL(5k)-PEG(1k)-NH2 is an amphiphile block copolymer which can self-assemble in water to form micelles (polycaprolactone (PCL) as a core is shielded by PEG). The core regions can serves as hydrophobic drugs reservoirs which can then be delivered 'stealthily' in vivo. The N-terminus (NH2) can be readily reacted with an NHS ester or with a carboxylic acid in the presence of an activator such as HATU/EDC. Reagent grade, for research purpose.