The top international journal "Biomaterials" reported an exciting research result. Professor Chen Shanshan's team at the Institute of Metal Research, Chinese Academy of Sciences, successfully developed a high-performance chitosan-grafted copper ion (Cs&Cu) functional coating, which systematically solved the challenges of "excessive degradation" and "incomplete endothelialization" of magnesium alloy stents. It is worth mentioning that in the critical surface pretreatment step of this research, the team used the CPC-B-13.56 plasma cleaning machine provided by CIF to activate the stent base, laying a solid foundation for the subsequent strong bonding and functional performance of the coating.
According to the detailed description in the paper, before spraying the Cs&Cu functional coating, the research team needed to perform surface treatment on the existing polybutylene adipate-terephthalate (PBAT) inner protective coating. Using CIF's CPC-B-13.56 plasma cleaner, the sample was plasma treated for 60 seconds in an oxygen (O₂) atmosphere at 60W power. This treatment step is crucial. The plasma activates the surface of the PBAT coating, significantly enhancing its hydrophilicity and surface energy, allowing the subsequently sprayed chitosan-copper solution to better wet, spread, and firmly adhere to the surface of the stent, thereby forming a uniform, stable, and bioactive functional coating.
After countless rounds of formula optimization and experimental verification, the final coating demonstrated exciting comprehensive performance: 1. Rapid endothelialization: In vitro experiments showed that the coating can greatly promote the adhesion, spreading, and proliferation of vascular endothelial cells, resulting in healthy cell morphology and networked connections. Even more surprising, in a rabbit carotid artery implantation model, the stent surface was essentially completely covered with endothelial cells in just one week, achieving rapid endothelialization and buying valuable time for vascular repair. 2. Effective degradation control: After three months of in vivo experiments, the results showed that the degradation rate of the stent with the functional coating was significantly reduced by 50% compared to the control group. This means that the stent can provide more durable and safe mechanical support for diseased blood vessels, avoiding the risks of premature degradation. 3. Excellent blood compatibility: The coating exhibits an extremely low hemolysis rate and can effectively reduce platelet adhesion and activation, prolong clotting time, and demonstrate excellent anti-coagulant properties, reducing the risk of thrombosis at the source. 4. Actively regulate the immune environment: Studies have found that the coating can actively guide macrophages in the body to polarize toward the anti-inflammatory M2 type, reducing the inflammatory response after implantation, and effectively inhibiting excessive proliferation of the endothelium by precisely regulating the expression of endothelial function-related proteins (such as upregulating p-eNOS and downregulating FDPS), providing double protection for long-term vascular patency.
