Antibiotic-releasing mesh coating to reduce prosthetic sepsis: an in vivo study.

BACKGROUND: Mesh related infections are a major challenge with few adequate prevention and treatment options. We evaluate the ability of a slow affinity based drug-releasing polymer to prevent a Staphylococcus aureus mesh infection using an in vivo animal model.
METHODS: A surgical wound infection model was used to evaluate a vancomycin (VM) drug loaded polymer. Fifty animals underwent creation of a dorsal subcutaneous pocket, insertion of a standard piece of polyester mesh and an inoculum of a clinical strain of green fluorescent protein (GFP) labeled S. aureus (SA) (10(4) CFU/mL). Animals were then randomly allocated to different treatment groups [saline flush (n = 10), VM flush (n = 20), VM polymer coated mesh (n = 20)]. Local tissue and mesh were evaluated at 2 (n = 25) and 4 wk (n = 25) via standard culture studies.
RESULTS: Median GFP SA growth from tissue-mesh homogenates were as follows: 2 wk: saline flush = 2.2 × 10(7) CFU/g; VM flush = 1.6 × 10(6) CFU/g; VM polymer = sterile cultures [P value 0.0001]; 4 wk: saline flush = 1.5 × 10(6) CFU/g; VM flush = 1.6 × 10(3) CFU/g; VM polymer = sterile cultures [P value 0.001].
CONCLUSION: Mesh infections pose a significant challenge in hernia surgery with suboptimal treatment modalities and little innovation. Using an in vivo wound infection model our novel affinity based drug delivering polymer was able to effectively prevent a SA mesh infection with efficacy demonstrated at 2 and 4 wk.