Functional Biomaterials for Vascular Healing After Percutaneous Coronary Intervention: From Surface Engineering to Clinical Translation

Percutaneous coronary intervention (PCI) creates a dynamic blood–material–tissue interface in which thrombosis, inflammation, smooth muscle cell proliferation, and endothelial recovery evolve simultaneously. This narrative review examines coronary biomaterials using a healing-centered translational framework that links material properties to molecular and cellular responses, tissue-level healing, measurable structural and functional phenotypes, and clinical outcomes. We review the evolution from bare-metal and drug-eluting stents to polymer-free systems, drug-coated balloons (DCBs), bioresorbable scaffolds, and bioactive or biomimetic surfaces. Particular emphasis is placed on strut geometry, polymer chemistry and degradation, drug-release kinetics, surface properties, corrosion behavior, endothelial barrier function, macrophage responses, thrombogenicity, and neointimal growth. Structural coverage on intravascular imaging is distinguished from functional endothelial recovery, which requires complementary biological or physiological assessment. Randomized evidence is interpreted at the level of the tested device, formulation, lesion, and procedural strategy; newer platforms are not assumed to confer class-wide superiority. Future progress will require multifunctional, healing-responsive platforms that integrate antithrombotic, pro-endothelial, immunomodulatory, and controlled-delivery functions while demonstrating mechanical durability, comparative clinical effectiveness, manufacturability, and cost-effective scalability.