Biodegradable Thermogelling Poly(D,L‐lactide‐co‐p‐dioxanone)‐Poly(ethylene glycol)‐Poly(D,L‐lactide‐co‐p‐dioxanone) Triblock Copolymer

Abstract

Abstract Thermogelling poly( D , L ‐lactide‐co‐p‐dioxanone)–poly(ethylene glycol)–poly ( D , L ‐ lactide‐co‐p‐dioxanone) [P(LA‐PDO)–PEG–P(LA‐PDO)] triblock copolymers were successfully prepared by ring‐opening copolymerization of D , L ‐lactide and p‐dioxanone in the presence of PEG as a macromolecular initiator and stannous octoate as a catalyst. The aqueous solutions of the copolymers underwent clear double sol–gel and then gel–sol transitions with increasing temperature from 0 to 50 °C. It was found that the lower critical solution transition (LCST) temperature could be effectively controlled by adjusting the molar ratio of LA/PDO or PEG length in the copolymers. The introduction of PDO units into the hydrophobic block has greatly accelerated the water dissolution rate of the copolymers and facilitated the drug formulation. The developed thermosensitive hydrogel has suitable sol–gel transition temperature and is a promising injectable material for drug delivery depot and tissue engineering scaffold.