Improved mechanical properties of poly(l-lactic acid) stent coated by poly(d, l-lactic acid) and poly(l-lactic-co-glycolic acid) biopolymer blend

Biopolymer coating is widely used in stent for drug delivery while few researches relate to its effect on mechanical properties. The strategy of blending poly(d, l-lactic acid) (PDLLA) and poly(l-lactic-co-glycolic acid) (PLGA) (100/0, 80/20, 50/50, wt/wt) was adopted in this study to explore solutions. Experiments on radial force, bending stiffness and surface morphology of poly(L-lactic acid) stents were carried out to study the comprehensive influence of coatings with different formulations on the mechanical properties of stents. Results suggested that stents coated with PDLLA/PLGA (80/20) have shown the most superior radial supporting performance and axial flexibility. Moreover, scanning electron microscopic image of surface morphology of stents showed reliable adhesion between the coatings and stents. This study can provide a feasible method for improving the mechanical properties of bioresorbable vascular stents.