Effect of trimethylene carbonate segments on the structure and properties of poly(L-lactide-glycolide-trimethylene carbonate) terpolymers for biodegradable vascular stents

The total biodegradable vascular stent made of poly(L-lactide-glycolide-trimethylene carbonate) terpolymers with excellent performances has the potential to be used in a new generation of medical implant devices. In this work, the properties and structure of terpolymers were investigated, which were found to be controlled by the composition of the copolymer chain. The amorphous trimethylene carbonate segments not only disturbed the sequence regularity of the L-lactide segment, but also reduced the crystallization ability of the material. Furthermore, it is the flexible segments in the terpolymer chains that improve the plastic flow capacity, increase the flexibility of chains as well as reduce the apparent activation energy of thermal degradation of materials. Such a chain structured terpolymer exhibited good extrudability and buildability in 3D printing and formed a vascular stent with a cohesion entanglement characteristic microstructure during the process. The crush resistance with radially applied load and crush resistance with parallel plates of stent were 2561.4 mm Hg and 0.24 N/mm, respectively. Synthesis, structure and properties of poly(L-lactide-glycolide-trimethylene carbonate) terpolymers.image