Polylactide-Based Chiral Porous Monolithic Materials Prepared Using the High Internal Phase Emulsion Template Method for Enantioselective Release

Polylactide [PLA, two enantiomers: poly­(l-lactide) (PLLA) and poly­(d-lactide) (PDLA)] has been widely applied as biomaterials because of its biocompatibility, biodegradability, and good mechanical capacity. However, the chirality of PLA materials has not been intensively explored yet. In the present study, chiral porous poly­(high internal-phase emulsion)­s (polyHIPEs) derived from enantiopure PLAs were successfully prepared via a HIPE template method. The resulting polyHIPEs show optical activity. More interestingly, the polyHIPEs demonstrate enantioselective release capacity, using cinchona alkaloid and naproxen as the model chiral drugs. Notably, PLLA-based polyHIPE shows enantioselectivity in both the drug-loading step and drug-releasing step, while PDLA-based polyHIPE fails. The interesting finding is essentially different from other chiral polymer materials reported earlier. The cytotoxicity test demonstrates that all the three types of polyHIPEs, PLLA-, PDLA-, and PDLLA-based polyHIPE show biocompatibility; however, their different chirality exerts varying effects on cell growth. Accordingly, special attention should be devoted to the chirality of PLA when used as biomaterials.