The role of TGF-beta1 as a determinant of foreign body reaction to alloplastic materials in rat fibroblast cultures: comparison of different commercially available polypropylene meshes for hernia repair

BACKGROUND: Animal experiments on hernia repair demonstrated better biocompatibility of light-weight polypropylene meshes. However, implanted medical devices trigger a variety of adverse tissue responses, such as inflammation, fibrosis, infection and thrombosis, but the mechanisms involved in such responses remain largely unknown. This study aimed to determine the effect of transforming growth factor beta1 (TGF-beta1) on host tolerance by quantification of foreign body reaction in cultured fibroblasts depending on the amount and composition of implanted material used for hernia repair. MATERIALS AND METHODS: An NRK-49F fibroblast culture was incubated in the presence of 4 commercially available meshes approved for hernia repair. A mesh-free cell suspension served as a control group, in which the influence of TGF-beta1 on fibroblasts was evaluated. Levels of TGF-beta1 in the supernatant were dynamically measured in a time interval of 6 to 96 h and cell proliferation rates were assessed colorimetrically using MTT test. RESULTS: A dose-dependent suppression of fibroblasts proliferation by TGF-beta1 was observed. All meshes suppressed the secretion of TGF-beta1 and conversely increased significantly cell proliferation in comparison to the control group (p<0.01) in the first 24 to 48 h of incubation. That effect was more pronounced in meshes partially containing absorbable material when compared to samples of pure polypropylene meshes (p<0.05) and to the control group (p<0.001). CONCLUSION: Our experiment revealed that early biological reaction of connective tissue cells towards polypropylene meshes and their variants depended much more on the composition and type of the material than on its absolute amount. The assumption that material weight reduction alone might affect the foreign body reaction of mesh implants could not be confirmed by our in vitro study.