Effects Of Chitosan Coatings On Polypropylene Mesh For Pelvic Floor Reconstruction
Pelvic floor reconstruction is usually accompanied with the implantation of a surgical mesh, which frequently results in a foreign body response with associated complications. An ideal surgical mesh that allows force generation of muscle tissues without significant granulation tissue and/or fibrosis is of significant clinical interest. In this dissertation, the in vitro and in vivo responses of a chitosan coating on high molecular weight polypropylene mesh (Ch-PPM) in comparison with commercially available meshes were explored. In the first study, we found that application of a 0.5% (w/v) Ch-PPM elicited preferential attachment of myoblasts over fibroblast attachment in vitro. Therefore, we tested the hypothesis that 0.5% Ch-PPM will encourage skeletal muscle tissue ingrowth and decrease fibrosis formation in vivo. In the second topic of investigation, we implanted 0.5% Ch-PPM, collagen-coated polypropylene mesh (PelvitexTM; C.R. Bard), and polypropylene (Avaulta Solo®; C.R. Bard) alone using a rat abdominal defect model. Force generation capacity and inflammatory response of each mesh were evaluated 2, 4, and 12 weeks post-implantation. We found that chitosan coating is associated with the restoration of functional skeletal muscle with histomorphologic characteristics that resemble native muscle and an early macrophage phenotypic response that has previously been shown to lead to more functional outcomes. Finally, we tested the mesh types in the same in vivo rat abdominal defect model to: 1) establish a relationship between the ratio of collagen types I/III and mechanical strength, and 2) determine the collagen deposition and mechanical strength of a chitosan-coated polypropylene mesh. By characterizing the inflammatory response, muscle contractility, and structural properties of mesh types after introduction in a small animal model, we hope to provide more insight for clinicians to reach a more educated decision for selection of a particular material for pelvic floor repair.
biomechanics; tissue engineering; pelvic floor; skeletal muscle; abdominal wall model
Bonassar, Lawrence; Chu, Chih-Chang
Ph. D., Mechanical Engineering
Doctor of Philosophy
dissertation or thesis