PCL(10k)-PEG(3k)-COOH is a monofunctional amphiphile polymer with COOH terminal which can react with amine in the presence of activating agent, such as HATU or EDC. The polymer consists of hydrophobic polycaprolactone (PCL) and hydrophilic PEG. It can be used to encapsulate hydrophobic drugs for targeted drug delivery. Reagent grade, for research purpose.