Antibacterial and anti-inflammatory activities of chitosan/copper complex coating on medical catheters: In vitro and in vivo

Copper ions (Cu) grafted chitosan coating was prepared using the pneumatic spraying method on the silicone rubber surface. Coating's surface properties, morphology, composition, Cu releasing behavior, antibacterial, and anti-inflammatory activities are investigated and discussed. Surface properties, composition, and morphology were investigated by scanning electron microscopy (SEM) and contact angle measurements. The antibacterial activity has been tested with Escherichia coli and Staphylococcus aureus suspensions in vitro. Besides, the morphology of the biofilm was inspected with a field emission SEM. To evaluate the anti-inflammatory activity and biosafety of the coating in vivo, the optimized coating samples and control groups were implanted subcutaneously into the back of mice. The bacterial environment model was established by injection of the bacterial suspension. The morphology and bacterial adhered on the surface of catheters and the surrounding tissues were analyzed after 5 days of implantation. As in vitro results, the number of adhered bacterial on the surface of the silicon rubber surface was decreased, and the anti-inflammatory rate was increased by the intensify of the Cu content in chitosan coating. As for in vivo results, after 5 days of implantation, there was no evident inflammation in the surrounding tissues of all catheters in all without the S. aureus injected group. In the injected chitosan/Cu coated group; the inflammation, the number of the adhered bacteria were observed less than other injected samples without Cu; no inflammation were noticeable. Results indicate that the Cu-modified chitosan coating can confer excellent antibacterial and anti-inflammatory activity as applied on medical catheters.

Automated summary

In this study, copper ion-grafted chitosan coating was prepared on the silicone rubber surface using the pneumatic spraying method. The surface properties, morphology, composition, copper releasing behavior, antibacterial, and anti-inflammatory activities of the coating were investigated. The results showed that the copper-modified chitosan coating exhibited excellent antibacterial and anti-inflammatory activities when applied on medical catheters.