Engineered probiotics biofilm enhances osseointegration via immunoregulation and anti-infection.

Abstract

Preventing multidrug-resistant bacteria-related infection and simultaneously improving osseointegration are in great demand for orthopedic implants. However, current strategies are still limited to a combination of non-U.S. Food and Drug Administration-approved antibacterial and osteogenic agents. Here, we develop a food-grade probiotic-modified implant to prevent methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) infection and accelerate bone integration. <i>Lactobacillus casei</i> is cultured on the surface of alkali heat-treated titanium (Ti) substrates and inactivated by ultraviolet irradiation to avoid sepsis induced by viable bacteria. This inactivated <i>L. casei</i> biofilm shows excellent 99.98% antibacterial effectiveness against MRSA due to the production of lactic acid and bacteriocin. In addition, the polysaccharides in the <i>L. casei</i> biofilm stimulate macrophages to secrete abundant osteogenic cytokines such as oncostatin M and improve osseointegration of the Ti implant. Inactivated probiotics modification can be a promising strategy to endow implants with both excellent self-antibacterial activity and osteointegration ability.