Recent Developments in Hemocompatible Surface Coatings

Hemocompatible coatings are critical for improving the performance and safety of blood-contacting cardiovascular devices. This review provides a comprehensive overview of the current landscape of surface modifications, focusing on heparinized coatings, diamond-like carbon (DLC) layers, zwitterionic hydrogels, and endothelial-mimetic nitric oxide (NO)-releasing surfaces. We analyze the mechanisms of action, design strategies, immobilization approaches, advantages and limitations, and recommended metrics for evaluating coating performance under physiological shear and flow conditions. Clinical and preclinical evidence from stents, vascular prostheses, catheters, extracorporeal circuits, mechanical valves, and ventricular assist devices (VADs) is summarized, highlighting the translational relevance of each technology. Hybrid coatings, combining active anticoagulant function with passive antifouling or tribological enhancements, emerge as the most promising strategy for long-term hemocompatibility. Key gaps in the field include the lack of standardized evaluation protocols, limited long-term clinical validation, and insufficient comparative studies across device types and coating technologies. We propose a decision framework linking device type, flow regime, and coating strategy, alongside an integrated hemocompatible index to facilitate quantitative comparison and guide future development. This synthesis provides researchers and clinicians with a practical reference for selecting and evaluating hemocompatible surfaces, emphasizing the balance between mechanical durability, biological function, and clinical applicability.