Preparation and In-Vitro Analysis of a Polyethylenimine Coating on Hernia Meshes

Background: Certain coatings such as titanium may improve the biocompatibility of hernia meshes. The coating with biopolymers such as polyethylenimine (PEI) can also improve the material characteristics of implants. This approach has, however, not yet been explored. Thus, it was the aim of the present work to clarify if and how hernia meshes with their three-dimensional structure can be successfully coated with PEI and with which technique this coating can be best analysed. Methods: Commercially available meshes made from polypropylene, polyester and ePTFE have been coated with PEI. The coating was analysed via cell proliferation test (mouse fibroblasts), electron microscopy, X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. Cell viability and cytotoxicity were tested by the MTT test. Results: With the PEI surface modification, mouse fibroblasts grow faster and in greater numbers on the mesh surface. XPS as well as fluorescence microscopy show weaknesses in their applicability and meaningfulness because of the three-dimensional mesh structure while XPS showed overall better results. Optical proof in the electron microscope after cell fixation was not unambiguously accomplished with the techniques used here. In the MTT test, no cellular damage from the PEI coating was detected after 24 hours. Conclusion: The present results show for the first time that PEI coating of hernia meshes is possible and effective. The PEI coating can be achieved in a fast and cost-efficient way. Further investigations are necessary with respect to coating quality and cytotoxicity before such a coating may be used in the clinical routine. In conclusion, PEI is a promising polymer that warrants further research as a coating for medical implants.