A Novel Stereocomplex Poly(lactic acid) with Shish-Kebab Crystals and Bionic Surface Structures as Bioimplant Materials for Tissue Engineering Applications.

Abstract

The development of green material possessing with great mechanical properties and biocompatibility has become a primary goal for high-performance biological material applications. Herein, the oriented shish-kebab crystals of stereocomplex poly(lactic acid) (SC-PLA) are first reported to be successfully fabricated through a feasible solid-state drawing (SSD) process to simultaneously enhance the mechanical performance and biocompatibility. The resultant biomaterial exhibits a tensile strength of 373 MPa and elongation about 9%, with elastic modulus about 8.1 GPa. Such an outstanding toughening effect is due to an amalgamation of enhanced crystallinity of epitaxial secondary growth lamellae and orientation degree of the fibrous backbone of the SC-PLA samples, both gradually increasing with the draw ratio of SSD increasing. Uniquely distinguished from the typical biomedical polymer with the smooth surface structure, the as-obtained SC-PLA samples possess a surface morphology of parallel microgrooves within ridge structures, attributing to the highly oriented fibrous backbone structure complemented with regularly arranged epitaxial lamellas. This unique trait well represents the human vascular endothelial microstructure that is desirable for cell adhesion-growth to extend its proliferation, differentiation, and activity on the surface of SC-PLA.