Fabrication of antibacterial silicone composite by an antibacterial agent deposition, solution casting and crosslinking technique

摘要

The key problems faced in developing indwelling catheters are how to incorporate antibacterial agents into the substrate and how to improve the antibacterial effectiveness. In this study, an antibacterial composite coating layer is inversely in situ formed on the silicone substrate by a novel technique involving deposition of an antibacterial agent, solution casting and crosslinking of a silicone resin. The antibacterial particles were strongly bonded to the matrix silicone and evenly dispersed on the coating surface. Moreover, energy-dispersive X-ray analysis revealed the gradient distribution of the antibacterial agent, perpendicular to the composite surface. The co-instantaneous crosslinking within the coating layer and polymer substrate as well as the graded structure formed lead to good adhesion between the two parts. The silicone composite shows a highly efficient antibacterial activity with no cytotoxicity to HL-60 cells. Compared with the commonly used methods of incorporating antibacterial agents into the silicone substrate, such as multiple dip-coating, surface grafting or simple blending, the proposed process is easily operated and is promising for forming a percutaneous or subcutaneous device with the capacity for efficient sterilization in an economical way.