Infection prevention using affinity polymer-coated, synthetic meshes in a pig hernia model

Abstract

Background Given concern for hernia mesh infection, surgeons often use biologic mesh which may provide reduced risk of infection but at the cost of decreased repair durability. We evaluated mesh coating to provide sustained release of antibiotics to prevent prosthetic mesh infection and also allow a durable repair. Materials and methods Cyclodextrin-based polymer was crosslinked onto multifilament polyester mesh and loaded with vancomycin (1.75 mg/cm2). Pigs received modified meshes (n =6) or normal, untreated meshes (n =4), which were implanted into acute 10 × 5 cm ventral hernia, then directly inoculated with 106 colony-forming unit (CFU) of methicillin-resistant Staphylococcus aureus (MRSA). These were compared to animals receiving normal, uninfected mesh. All mesh was secured in an underlay bridge manner, and after 30 d, the abdominal wall was removed for quantitative bacterial culture and biomechanical analysis. Results All animals survived 30 d. All six animals with coated mesh cleared MRSA infection. The four control animals did not clear MRSA (P =0.005). Quantitative bacterial load was higher in standard mesh versus drug-delivery mesh group (2.34×104 versus 80.9 CFU/gm). These data were log10-transformed and analyzed by Welch’s t-test (P = 0.001). Minimum number of CFUs detectable by assay (300) was used instead of zero. Biomechanical analysis of controls (1.82 N/mm infected; 1.71 N/mm uninfected) showed no difference to the modified meshes (1.31 N/mm) in tissue integration (P = 0.15). Conclusions We successfully prevented synthetic mesh infection in a pig model using a cyclodextrin-based polymer to locally deliver vancomycin to the hernia repair site and clearing antibiotic-resistant bacteria. Polymer coating did not impact the strength of the hernia repair.

Elucidating the Structure-Function Relationship of Solvent and Cross-Linker on Affinity-Based Release from Cyclodextrin Hydrogels

“…Degradation and host response to implanted materials can significantly alter release behavior. To date, no excessive host response has been found in rodents [15] or pigs [24] out to 30 days and preliminary data in pigs at 60 d shows no change from 30 d (unpublished data). The degradation products of pCD are glucose and do not elicit acidification or inflammatory response.…”

Cyclodextrin polymer coatings resist protein fouling, mammalian cell adhesion, and bacterial attachment

“…We envision that pCD might be applied as coatings for medical devices, such as textile implants. Specifically, CD-based polymer coatings have previously been investigated for use as surgical mesh coatings that could enable controlled antibiotic/drug release 65,87,[120][121][122][123] , but it would also be noteworthy to explore the potential of these materials to prevent post-surgical adhesions. The formation of tissue adhesions on a surgical fabric surface is preceded by two events that CDbased polymers are shown to be capable of mitigating: 1.)…”

Infections associated with mesh repairs of abdominal wall hernias: Are antimicrobial biomaterials the longed-for solution?

“…to ±0.30 mg/cm 2 of prosthesis). Using a higher vancomycin loading (1.75 mg/cm 2 ) on similar bioactive mesh allowed to clear infection in an infected pig model [89].…”