Multifunctional poly(amine-ester)-type hyperbranched polymers: lipase-catalyzed green synthesis, characterization, biocompatibility, drug loading and anticancer activity

Hyperbranched polymers (HBPs) have attracted more and more attention because of their specially branched architecture and interesting properties. A series of novel poly(amine-ester)-type HBPs were synthesized through CALB-catalyzed polycondensation between triethanolamine (TEOA) and diesters after the optimization of reaction conditions. The precise structure including degree of branching, components percentage, and the controllable terminal structures at the outer surface were determined by FTIR, H-1 NMR, C-13 NMR, 2D NMR and GPC. The interesting multifunctionality displayed by the poly(amine-ester)-type HBPs was investigated. These HBPs could be degraded efficiently under the catalysis of lipase in weak acid buffer. The amphiphilic HBPs with hydroxyl terminals were able to form multimolecular micelles with 250-400 nm diameter, and 0.042 g L-1 CMC. They were nontoxic to COS-7 cells, while they could effectively inhibit the growth of cancer cells HepG2 with IC50 of 130 mu g mL(-1) after an anticancer drug was encapsulated within the micelles. All these results indicated the prepared poly(amine-ester)-type HBPs can serve as multifunctional biomaterials for biomedical applications.