Fabrication of poly(D, L-lactide-co-ε-caprolactone) with elastic-memory function and controlled biodegradability

Polylactic acid (PLA) is a biodegradable material for tissue engineering, while its mechanical fragility and uncontrollable biodegradability limit its further application in biomedical fields. In this study, a series of poly(D, L-lactide-co-ε-caprolactone) (PDLCL) gradient copolymers were synthesized through ring-opening polymerization by modulating the lactide/caprolactone (LA/CL) monomer ratio, which is expected to achieve excellent elasticity and controllable degradation properties. In particular, the introduction of 35% CL monomer into PLA gave PDLCL6535 copolymers with improved flexibility (elongation at break is 607.3 ± 24.0%, 152 times that of PLA) with relatively high tensile strength (13.6 ± 0.4 MPa), offering a good elastic-memory property (elastic recovery could reach 91.2%). Furthermore, the biodegradable rate and hydrophilicity of PDLCL copolymers improved with the CL content increase. In vitro biocompatibility evaluation indicated that the PDLCL materials had good biosafety and reached the level I, rendering PDLCL an ideal candidate for the development of medical devices, especially elastic film, and tubes.