Antimicrobial Silicon Rubber Crosslinked with Bornyl-Siloxane.

Silicone rubber (SiR) has a wide range of medical applications, but it lacks antimicrobial properties, leading to potential infection issues with related implants or medical devices. Most studies focus on adding anti-bacterial agents or surface modification, which usually result in composites with anti-bacterial properties, rather than synthesizing SiR with intrinsically antimicrobial performances. To tackle this issue, a double substituted bornyl-siloxane crosslinker (BC) is designed. This crosslinker can react with hydroxy-terminated polydimethylsiloxane (PDMS) at room temperature to yield SiR with borneol side groups. The process is simple without using additional solvents. Antimicrobial assay on SiR cured with different ratios of BC/PDMS showed that 20 wt.% BC cross-linked network exhibited outstanding anti-bacterial adhesion (Escherichia coli 99.4%, Staphylococcus aureus 97.3%) performance and long-lasting anti-mold (Aspergillus niger over 99% for 30 days) adhesion properties. Moreover, the subcutaneous implantation model in mice demonstrated its excellent anti-infection, biocompatibility and safety. Therefore, this material is promising for widespread adoption in the medical field, especially in silicon-based products or coatings.