Novel laser-textured grooves extended to the sidewall edges of CoCr surfaces for rapid and selective endothelialization following coronary artery stenting

The long-term performance of coronary stents is often compromised by delayed endothelialization and late thrombosis, particularly in drug-eluting stents (DES) that impair vascular healing. To address these challenges, we report a novel micro-hierarchical surface modification that integrates sidewall edge structuring into grid patterns on cobalt-chromium (CoCr) stents, enhancing endothelial cell (EC) interactions without compromising mechanical integrity. Laser fabrication was used to create microgrooves (5-30 μm) with extended sidewall edges, designed to promote rapid EC adhesion and proliferation. Comprehensive in vitro evaluations, including EC viability, adhesion, and platelet aggregation assays, demonstrated that stents with grid pattern and sidewall edge structuring on an already fabricated stent enhanced EC viability approximately six-fold compared to the non-patterned controls, reaching 2276 ± 220 cells/ml by day three of culture. The sidewall edges provided possible promising stable anchoring sites and gateway channels, improving EC attachment and selective alignment, while also substantially reducing platelet deposition in grooved regions. To ensure these surface modifications did not affect mechanical performance, comprehensive three-point bending and radial compression tests were conducted. No significant differences were observed compared to coronary stents, confirming that the micro-hierarchical texture with sidewall edges maintains essential mechanical properties. Together, these findings highlight the potential of sidewall edge-integrated grid patterns to accelerate endothelialization and reduce thrombogenic risks, offering a promising strategy for improving the design and long-term performance of next-generation coronary stents.