Fabrication and characterization of PLLA/PCL/Mg‐Zn‐Y alloy composite stent

Abstract

Bioresorbable polymeric stents (BPS) can become a promising alternative over permanent stents, as it reduce in‐stent thrombosis, endothelial dysfunction, and thrombogenicity. Although, a few limitations like uncontrolled degradation, inadequate strength, and lack of radiopacity restrict its application. Thus, a novel bioresorbable radiopaque Mg‐Zn‐Y Alloy (BRM) of high effective atomic number (Zeff) was developed to reinforce and attenuate X‐rays in the polymers. After that, the optimized BRM microparticles were blended with radiolucent poly (L‐lactide)/poly (ε‐caprolactone) (PLLA/PCL) polymer and extruded into biaxially expanded (BAE) tubes. Further, in this work, BAE tubes of PLLA/PCL/BRM and PLLA/PCL were cut using the optimized Femtosecond laser machine (FSLM) parameters for fabricating cardiovascular stents. These stent materials were assessed to sustain the angioplasty procedure, such as radial strength, crimping, recoil, expansion process, and performance under cycling loading.Highlights A novel biodegradable radiopaque Mg‐Zn‐Y alloy was developed. Adding Mg alloy (5% wt.) in PLLA/PCL imparts X‐ray visibility. Composite stents show better compressive radial strength and flexibility. It also reveals low crimping recoil, expansion recoil, and foreshortening. Composite stents can withstand arterial vasomotion better than PLLA/PCL.