PLGA-PEG-Acid is a diblock copolymer with an acid group at the distal end of PEG. PLGA-PEG-COOH of any MW of PEG and PLGA as well as L to G ratio can be custom synthesized to meet your project need. PEG-PLGA is an amphiphilic AB diblock copolymer consisting of a hydrophilic block polyethylene glycol (PEG) or polyethylene oxide (PEO) and a hydrophobic block poly(lactide-co-glycolide) (PLGA). The PEG polymer is capped a methyl ether group, and the hydrophobic block terminates with a hydroxyl group. PEGylated copolymers with biodegradable and biocompatible polyester segments can be used to prepare core-shell micelles, nanoparticles and microspheres. The hydrolytic degradability of polyester segments depend on the molecular weight and the spacer between ester groups (lactide, glycolide or caprolactone).