Improved collagen type I/III ratio at the interface of gentamicin-supplemented polyvinylidenfluoride mesh materials

Abstract

Formation of recurrent inguinal and incisional hernia shows an underlying defect in the wound-healing process with an insufficient quality of scar formation. Even after mesh repair an altered collagen formation and insufficient mesh integration has been found as main reason for recurrences. Therefore, the development of bioactive mesh materials to achieve a local modification of the scar formation to improve patients outcome is advisable. A polyvinylidenfluoride mesh material (PVDF) was constructed and surface modified by plasma-induced graft polymerization of acrylic acid (PVDF + PAAc). Surface supplementation was sought by binding of gentamicin to the provided active sites of the grafted mesh surfaces (PVDF+PAAc+Gentamicin). In vivo modulation of collagen formation was evaluated in a standardized animal model where an abdominal wall replacement was performed in 45 Sprague-Dawley rats. Seven, 21, and 90 days after mesh implantation, collagen/protein ratio and the collagen type I/III ratio as well as the expression of type I alpha 1 collagen mRNA (SYBR Green real-time RT-PCR) were analyzed at the perifilamentary region. Additionally, expression of matrix metalloproteinases (MMP-8/-13) has been investigated immunohistochemically. Implantation of the PVDF + PAAc + Gentamicin mesh induced a significantly decreased expression of MMP-8 and MMP-13 at the interface 21 and 90 days after implantation compared to the other groups. Whereas no significant effect was observed comparing the overall collagen/protein ratio, the quality of collagen formation expressed by the collagen type I/III ratio showed significantly higher ratios around the PVDF + PAAc + Gentamicin mesh 21 and 90 days after implantation. Correspondingly, an up to 5.3-fold expression of type I alpha 1 collagen mRNA was found. The present data confirm that a surface modification of PVDF mesh samples using plasma-induced graft polymerization of acrylic acid and supplementation of gentamicin is able to improve scar quality and mesh integration.