Dual-Function Sol–Gel Antibacterial Materials with Biphasic Octenidine Release for Decontamination and Long-Term Protection

In this research, a novel eco-friendly method for developing antibacterial sol-gel materials with microbial porous-forming templates is proposed. This approach compliments traditional surfactants with sustainable microbial templates, which are accessible, inexpensive, morphologically reproducible, and do not possess a toxic effect on the environment. Here, we synthesized a series of sol-gel materials using yeast and bacterial cells as templates. The best material based on the encapsulated bacteria <i>Paracoccus yeei</i> VKM B-3302 in methyltriethoxysilane and tetraethoxysilane in a ratio of 50/50 vol% after heat treatment at 800 °C was established after studying the parameters of release of the well-known cationic antiseptic octenidine dihydrochloride. It was shown that the release of octenidine from the formed silicon-containing materials occurred in two phases: rapid local release and subsequent prolonged action. This biphasic release enables a dual-function effect: rapid initial antiseptic action for immediate microbial decontamination, followed by sustained release for long-term microbial protection. The antibacterial properties were evaluated by inhibiting the growth of the phytopathogen <i>Rhodococcus fascians</i> VKM Ac-1462. The diameter of the inhibition zone was 12 mm and decreased to 11 mm within 25 days. The most effective material was loaded into the silicone sealant. A mixture containing 3-10% antibacterial material maintained the inhibition zone above 10 mm for 25 days, which emphasizes the high potential of the obtained material for medical applications such as implant treatments, antiseptic wound surfaces and industrial applications including medical filters and membranes. This study demonstrates the use of whole microbial cells as biotemplates for fabricating environmentally friendly sol-gel matrices with tunable porosity for the controlled release of antiseptics.