Heparin-mediated antibiotic delivery from an electrochemically-aligned collagen sheet.

BACKGROUND Implantable medical devices and hardware are prolific in medicine, but hardware associated infections remain a major issue. OBJECTIVE To develop and evaluate a novel, biologic antimicrobial coating for medical implants. METHODS Electrochemically compacted collagen sheets with and without crosslinked heparin were synthesized per protocol developed by our group. Sheets were incubated in antibiotic solution (gentamicin or moxifloxacin) overnight, and in vitro activity was assessed with five-day diffusion assays against Pseudomonas aeruginosa. Antibiotic release overtime from gentamicin infused sheets was determined using in vitro elution and high performance liquid chromatography (HPLC). RESULTS Collagen-heparin-antibiotic sheets demonstrated larger growth inhibition zones against P. aeruginosa compared to collagen-antibiotic alone sheets. This activity persisted for five days and was not impacted by rinsing sheets prior to evaluation. Rinsed collagen-antibiotic sheets did not show any inhibition zones. Elution of gentamicin from collagen-heparin-gentamicin sheets was slow and remained above the minimal inhibitory concentration for gentamicin sensitive organisms for 29 days. Conversely, collagen-gentamicin sheets eluted their antibiotic payload within 24 hours. Overall, heparin associated sheets demonstrated larger inhibition zones against P. aeruginosa and prolonged elution profile via HPLC. CONCLUSION We developed a novel, local antibiotic delivery system that could be used to coat medical implants/hardware in the future and reduce post-operative infections.