Figure 1.

Design of the entire study: the copolymer was synthesized by two simple steps. Firstly, propanetriol was employed as the initiator for the synthesis of 3S-PLGA by ring-opening polymerization. Secondly, 3S-PLGA was linked with PEG by acylation reaction, in which oxalyl chloride was used as the linkage. Then, the hydrophobic drug was incorporated into the hydrophobic core to evaluate the ability of this copolymer as the drug-delivery carrier.

Abbreviations: 3S-PLGA, three-arm star block poly(lactic-co-glycolic acid); PEG, polyethylene glycol; LA, lactic acid; GA, glycolic acid.