International Journal of Nanomedicine (Dec 2022)
Nanofiber Fractionalization Stimulates Healing of Large Intestine Anastomoses in Rabbits
Abstract
Martin Kralovic,1,2 Michal Vjaclovsky,3 Zbynek Tonar,4 Martina Grajciarova,4 Jana Lorenzova,5 Martin Otahal,6 Alois Necas,5 Jiri Hoch,3,7 Evzen Amler1,2 1Quality of Indoor Environment, University Centre for Energy Efficient Buildings, Czech Technical University in Prague, Bustehrad, Czech Republic; 2Department of Biophysics, Second Medical Faculty, Charles University in Prague, Prague, Czech Republic; 3Department of Surgery, Motol University Hospital, Prague, Czech Republic; 4Department of Histology and Embryology and Biomedical Centre, Faculty of Medicine in Pilsen, Charles University, Prague, Czech Republic; 5Section of Small Animal Diseases, Faculty of Veterinary Medicine, University of Veterinary Sciences Brno, Brno, Czech Republic; 6Department of Natural Sciences, Faculty of Biomedical Engineering in Kladno, Czech Technical University in Prague, Prague, Czech Republic; 7Department of Surgery, Second Medical Faculty, Charles University in Prague, Prague, Czech RepublicCorrespondence: Martin Kralovic, Quality of Indoor Environment, University Centre for Energy Efficient Buildings, Czech Technical University in Prague, Trinecka 1024, Bustehrad, 273 43, Czech Republic, Tel +420 224 356 701, Email [email protected]: A current topic of ma jor interest in regenerative medicine is the development of novel materials for accelerated healing of sutures, and nanofibers seem to be suitable materials for this purpose. As various studies have shown, nanofibers are able to partially substitute missing extracellular matrix and to stimulate cell proliferation and differentiation in sutures. Therefore, we tested nanofibrous membranes and cryogenically fractionalized nanofibers as potential materials for support of the healing of intestinal anastomoses in a rabbit model.Materials and Methods: We compared cryogenically fractionalized chitosan and PVA nanofibers with chitosan and PVA nanofiber membranes designed for intestine anastomosis healing in a rabbit animal model. The anastomoses were biomechanically and histologically tested.Results: In strong contrast to nanofibrous membranes, the fractionalized nanofibers did show positive effects on the healing of intestinal anastomoses in rabbits. The fractionalized nanofibers were able to reach deep layers that are key to increased mechanical strength of the intestine. Moreover, fractionalized nanofibers led to the formation of collagen-rich 3D tissue significantly exceeding the healing effects of the 2D flat nanofiber membranes. In addition, the fractionalized chitosan nanofibers eliminated peritonitis, significantly stimulated anastomosis healing and led to a higher density of microvessels, in addition to a larger fraction of myofibroblasts and collagen type I and III. Biomechanical tests supported these histological findings.Conclusion: We concluded that the fractionalized chitosan nanofibers led to accelerated healing for rabbit colorectal anastomoses by the targeted stimulation of collagen-producing cells in the intestine, the smooth muscle cells and the fibroblasts. We believe that the collagen-producing cells were stimulated both directly due to the presence of a biocompatible scaffold providing cell adhesion, and indirectly, by a proper stimulation of immunocytes in the suture.Keywords: cryogenic grinding, electrospinning, colorectal anastomoses, microvessels, collagen
