Potentiality of Antibacterial Gels for the Prophylactic Coating of Hernia Repair Prosthetic Materials

Prosthetic mesh infection constitutes one of the major postsurgical complications following abdominal hernia repair. Antibacterial coatings represent a prophylactic strategy to reduce the risk of infection. This study assessed the in vitro response of two antibacterial gels made of 1% carboxymethylcellulose (CMC) functionalized with an antiseptic (chlorhexidine, CHX) or an antibiotic (rifampicin, RIF), developed for the coating of polypropylene (PP) meshes for hernia repair. Fragments of a lightweight PP mesh (1 cm²) presoaked in the unloaded or drug-loaded CMC (0.05% CHX; 0.13 mg/mL RIF) were challenged with 10⁶ CFU/mL Staphylococcus aureus (Sa) and methicillin-resistant S. aureus (MRSA). Agar diffusion tests, sonication, turbidimetry, crystal violet staining, scanning electron microscopy and cell viability assays (fibroblasts, mesothelial cells) were performed to evaluate the response of the gels. Both compounds-especially the RIF-loaded gel-exerted a biocidal effect against gram-positive bacteria, developing wide inhibition halos, precluding adhesion to the mesh surface, and hampering bacterial survival in culture. The antibiotic gel proved innocuous, while lower viability was found in cells exposed to the antiseptic (p < 0.05). Together with their fast, affordable, convenient processing and easy application, the results suggest the potential effectiveness of these drug-loaded CMC gels in providing meshes with an antibacterial coating exhibiting great biocide performance.