A novel copolymer poly(lactide-co-beta-malic acid) with extended carboxyl arms offering better cell affinity and hemacompatibility for blood vessel engineering.

Abstract

Despite their increasing uses for cardiovascular and cerebrovascular tissue engineering, synthetic polymeric conduits still have their limitations in clinical applications, particularly in small vessels, mainly due to the thrombus formation. Seeding the synthetic scaffolds with endothelial cells (ECs) will potentially solve this problem, but this endothelialization approach demands synthetic materials with better hemacompatibility and cell affinity. To improve the currently used materials and screen for better surface properties, we synthesized copolymer of poly(lactide-co-beta-malic acid) (PLMA), and its derivatives with pendant hydroxyl arms (PLMAHE) or extended carboxyl arms (PLMA-ECA). We analyzed their physical and chemical properties, their hydrophilicity, and their degradation in physiological conditions. More importantly, their blood compatibility was investigated by the measurements of prothrombin time, activated partial thromboplastin time, and interaction with platelets; their cell affinity and cell growth potentials were observed using the human umbilical vein EC cultures. Results from these experiments showed that the copolymer with the carboxyl arms attracted little platelets, and exhibited better cell affinity and supported the cell proliferation, thus demonstrating the potential usefulness of PLMA-ECA for tissue engineering. We speculate that this novel material will offer new opportunities for the design of better vascular-engineered scaffolds owing to its improved biological and chemical properties.