Swollen-induced facile in situ preparation of silver nanoparticles incorporated into UV-curable silicone rubber for durable antimicrobial activity

Abstract

Silicone rubber plays a significant role in medical applications. However, its poor antibacterial characteristics often lead to related infections. Moreover, the presence of heavy metal residues in silicone rubber from conventional fabrication processes limits its application in medical devices. In this study, we developed a novel and straightforward approach for the preparation of UV-curable silicone rubber composites (PDMS@AgNPs) with durable antibacterial properties through a rapid and facile swollen-induced in situ reduction method without any heavy metal catalysts. The UV-curable silicone rubbers (PDMS-SH) were prepared using poly[(mercaptopropyl)methylsiloxane] (PMMS) and vinyl silicone, where the excessive thiol groups in PMMS not only facilitate a uniform cross-link network formation but also act as a reducing agent for silver nanoparticles (AgNPs). The mechanical properties, including hardness and swelling ratio, were found to be influenced by the molar ratio of sulfhydryl to vinyl groups. Remarkably, PDMS@AgNPs exhibited excellent antibacterial activity against S. aureus and E. coli, maintaining high efficacy even after 5 days of immersion, attributed to the stable incorporation of AgNPs within the cross-linked matrix. Furthermore, the composites exhibited low hemolysis rates and minimal cytotoxicity, indicating their potential as biocompatible materials for medical applications.