Polycaprolactone-based fused deposition modeled mesh for delivery of antibacterial agents to infected wounds

Infections represent a significant source of site morbidity following tissue trauma. Scarring and tissue adhesion remain the challenging issues yet to be solved. Prolonged inflammation and morphology of the re-epithelisated layer are important considerations. We hypothesized that the solution lies not only in the biochemistry of biomaterial but also the micro-architecture of the scaffold used as the matrix for wound healing. Targeted delivery of antibiotics may provide an efficacious means of infection control through adequate release. Here, we study the use of 3-dimensional polycaprolactone–tricalcium phosphate (PCL–TCP) mesh for the delivery of gentamicin sulphate (GS) fabricated using a solvent-free method. PCL–TCP meshes incorporated with varying loads of GS were evaluated in vitro for elution profile, antimicrobial efficacy and cytotoxicity. Results showed that PCL–TCP meshes incorporated with 15wt% GS (PT15) efficiently eliminate bacteria within 2 h and demonstrate low cytotoxicity. Subsequently, PT15 meshes were evaluated using an infected full thickness wound mice model, and observed to eliminate bacteria in the wounds effectively. Additionally, mice from the PT15 treatment group (TG) showed no observable signs of overall infection through neutrophil count by day 7 and displayed efficient wound healing (94.2% wound area reduction) by day 14. Histology also showed significantly faster healing in TG through neo-collagen deposition and wound re-epithelisation. The meshes from TG were also observed to be expelled from wounds while gauze fibers from CG were integrated into wounds during healing.