The Effect of Biopolymer Coatings on Hernia Meshes in a Rat Model

Abstract

Purpose: To improve biocompatibility and texture of hernia meshes has played a key role in tissue engineering for decades. Biopolymer (Polyethylenimine (PEI) and 3-Glycidoxypropyltrimethoxysilane (GOPS)) coating on Polypropylene (PP) and expanded Polytetrafluoroethylene (ePTFE) mesh showed promising results in fibroblast adhesion and cell growth in an invitro analysis. The objective of this animal study was to evaluate whether this may influence the incorporation into host tissue. Methods: 30 male Lewis rats were divided into 3 groups (n=10): Group 1: ePTFE/PEI, Group 2: ePTFE/GOPS, Group 3: PP/PEI. In each animal, a 3x0.5 cm coated mesh was implanted in the right rectus sheath in sublay position, the uncoated mesh was implanted on the left equally. After 90 days, the rats were sacrificed and each side of the rectus sheath was analyzed separately for adhesions and mechanical strength. Histopathological assessment included Gieson’s stain and haematoxylin-eosin staining. The Wilcoxon test was used for statistical analyses. Results: The GOPS-coated ePTFE tends to cause more adhesions. There was no significant difference in the mechanical strength within and between the groups, but the PEI-coated polypropylene was significantly less extendible (p<0.05) compared to the uncoated PP. In group 2, Gieson’s stain showed a significantly lower surrounding tissue reaction of foreign-body giant cells and scar tissue around the PEI-coated mesh compared to the uncoated ePTFE (p<0.05). Conclusions: It is possible to coat surgical mesh devices with biopolymers. They do not lead to a lack of mechanical strength. The GOPS-coating did not show any general positive effect on the biocompatibility of meshes. The PEIcoating resulted in a lower surrounding tissue reaction and in a less extendible abdominal wall and should therefore be investigated further.