Research Progress of Coatings for Implantable and Interventional Medical Devices

Implantable medical devices refer to medical devices (such as bone nail, artificial joint, etc.) that are surgically implanted and left in the body for a long time to support daily life activities. Interventional medical devices are medical devices (such as guide wire, catheter, etc.) that enter human organs or natural cavities for local examination and treatment during interventional surgeries. However, when implantable and interventional medical devices come into direct contact with human tissues and blood, the body may produce a rejection reaction leading to various side effects such as inflammation, vasospasm, and thrombosis. These complications pose surgical risks and can hinder the therapeutic effect. To address these issues, the work aims to explore one effective approach of applying biocompatible coating on the surface of implantable and interventional medical devices. In recent years, with the rapid development of materials science and coating preparation technology, various coatings with different functions have emerged. In this study, the research progress of five types of coatings for implantable and interventional medical devices, including hydrophilic, hydrophobic, antibacterial, anticoagulant and drug-loaded coatings was presented. Accordingly, the impact of the material composition and surface structure on the functionality of the coating was discussed. Hydrophilic coating is a lubricating coating with a water contact angle less than 90° and low friction. Its hydrophilic properties mainly depend on the hydrophilic chemical composition and surface roughness. Similarly, hydrophobic coating is a surface coating with water-repellent, anti-adhesion and self-cleaning properties that has a water contact angle greater than 90°. It is mainly achieved by constructing micro-nano composite structures with low surface energy materials. Antimicrobial coating is a hybrid coating that can effectively inhibit or kill microorganisms such as bacteria and fungi, which can reduce the risk of infection from implantable and interventional medical devices. On the one hand, antibacterial coating reduces the adhesion of microorganisms by using hydrophilic or hydrophobic materials to change the surface energy; on the other hand, antibacterial coating directly inhibits the growth of microorganisms by loading antibacterial agents. Anticoagulant coating is the medical device coatings used to prevent blood clotting and thrombosis, and has attracted increasing attention in recent years. It can be roughly divided into four categories according to different anticoagulant components: bioactive coating, bioinert coating, endothelial-specific growth factor coating and composite coating. Drug-loaded coating is a coating on the surface of implantable and interventional medical devices that can locally release active drugs, such as anti-tumor drug and anti-vascular endothelial proliferation drug, thereby improving the effect of surgical treatment and reducing side effects. Commonly used drug carrier materials include biodegradable polymers and nanoparticles, which can stably load and gradually release drugs. Furthermore, different forms of drug release and treatment strategies can be achieved by changing the ratio and structure of the drug carrier components in the coating. With the development of implantable and interventional medical devices, the demand for functional coatings with improved performance is also increasing. However, the existing coating technologies still have some shortcomings and challenges, such as poor long-term use of the coating, low durability, high preparation costs, and complicated processes. In the future, it is still necessary to develop novel functional materials and improve material preparation and production technologies to further improve the performance of implantable and interventional medical devices and provide better clinical application value for doctors and patients. © 2024 Chongqing Wujiu Periodicals Press. All rights reserved.