Totally bioresorbable composites prepared from poly(L-lactide)-co-(trimethylene carbonate) copolymers and Poly(L-lactide)-co-(glycolide) fibers as cardiovascular stent material

This paper aims to evaluate the potential of totally bioresorbable composites as cardiovascular stent material. Copolymers were synthesized by ring-opening polymerization of L-lactide (LLA) and 1, 3-trimethylene carbonate (TMC) with LLA-TMC ratios of 3/1, 4/1, and 5/1 and characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). Wt. 5% of poly(L-lactide)-co-(glycolide) (PLGA) fibers are used to reinforce PTMC-LLA copolymer matrices to prepare totally bioresorbable composites. Heat treatment under vacuum and oxygen plasma treatment are applied to improve the mechanical performance of the composites in terms of eliminating the imperfections inside, enhancing interfacial affinity, surface roughness, and enriching surface oxidative chemical bonds. After plasma treatment, the viscosity and tensile strength of the fibers decrease, but the surface chemical bonds are enriched and surface roughness is increased. The composites with 15-min plasma-treated fibers and 2 h heat treatment exhibit the highest tensile strength of 46 MPa, i.e., very close to that of PLLA (48 MPa), which is usually used as biodegradable stent material. Moreover, the tensile modulus of the above composite is 1711 MPa, which is only 34% of PLLA's modulus (4985 MPa). Therefore, novel composites with sufficient tensile strength and better flexibility are obtained as promising cardiovascular stent material. POLYM. ENG. SCI., 52:741-750, 2012. © 2011 Society of Plastics Engineers
INTRODUCTION With cardiovascular incidents increasing nowadays, minimally invasive treatments such as balloon angioplasty have become more and more attractive to the patients due to their minimal trauma without major cardiosurgery [...]