Bacterial cellulose and bacterial cellulose/polycaprolactone composite as tissue substitutes in rabbit corneas

Event Abstract Back to Event Bacterial cellulose and bacterial cellulose/polycaprolactone composite as tissue substitutes in rabbit corneas Paulo Victor S. Queiroz1, Fabrício L. Valente1, Rodrigo V. Sepúlveda1, Renato B. Eleotério1, Hernane S. Barud2, Emily C. Carlo Reis1 and Andréa P. Borges1 1 Universidade Federal de Viçosa, Veterinary Department, Brazil 2 Universidade do Estado de São Paulo, Institute of Chemistry, Brazil Progressive corneal ulcers or deep injuries require emergency intervention to restore eye integrity and prevent complications[1]. Allografts show the best results in keratoplasty, however, they have limited sources and may not be readily available[2]. Thus, studies of biopolymers for corneal tissue replacement to restore the appropriate refractive status of the eye are increasing[3]. Bacterial cellulose (BC) produced by Gluconacetobacter xylinus, and polycaprolactone (PCL) are two biopolymers which form a malleable biomaterial with high transparency when associated to each other[4]. This study aimed to test the performance of bacterial cellulose/polycaprolactone (BC/PCL) composite and pure bacterial cellulose (BC) as tissue substitutes in rabbits’ cornea. The project was previously approved by Ethics Committee on Animal Use , #88/2011. A superficial ulcer (5 mm in diameter and 0.2 mm deep) was produced on the right cornea of 36 rabbits. Then, an interlayer pocket was created in all circumference of the defect. Twelve animals received BC/PCL composite membrane and 12 were treated with BC membranes, both with 8 mm diameter, placed with borders inside the pocket. The remaining rabbits received no treatment, constituting the control group. Three animals of each group were euthanized at three, seven, 21, and 45 days after surgery for histological analysis (H&E and Sirius red) and electron microscopy scanning of the cornea along with the implant. Clinical observation showed signs of moderate inflammatory process, which decreased from day 20 in implanted groups. Corneal edema was present from day one in the control group while in the groups receiving the implant cornea started to turn opaque after three days. This result shows that the membranes protected the ocular surface in the absence of epithelium, preventing entry of fluid, which immediately causes edema, presenting only late opacity, which can result from the infiltration and cellular changes that occur during corneal healing, and not hydric changes in the stroma[5]. Histology showed absence of epithelium on the membranes, fibroplasia near the implants, lymphohistiocytic inflammatory infiltrate with giant cells, collagen disorganization, with a predominance of type III collagen in both implant groups. These results differ from other works that demonstrated BC biocompatibility with no significant inflammation[6]. The presence of type III collagen is a strong indication that a healing process is taking place in the stroma[7]. Electron microscopy revealed the presence of cells and extracellular matrix adhered to the surface of the membranes. Although inflammatory response is acceptable and the biomaterial allowed cell adhesion, these processes, as seen in this study, associated to clinical signs, allowed us to conclude that the membrane did not play a satisfactory role as corneal tissue substitute. CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil; CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico - Brazil; FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais - BrazilReferences:[1] L.J. LAI and G.H. HSIUE, Functional biomedical polymers for corneal regenerative medicine, Reactive & Functional Polymers. Vol. 67, 2007.[2] B.M. PRESSLER, Transplantation in Small Animals, Veterinary Clinics of North America: Small Animal Practice. Vol. 40, 2010.[3] E.M. ESPANA, A.C. ACOSTA, J. STOIBER et al., Long-term follow-up of a supradescemetic keratoprosthesis in rabbits: an immunofluorescence study, Graefe's Archive for Clinical and Experimental Ophthalmology. Vol. 249, 2011.[4] H.S. BARUD, S.J.L. RIBEIRO, C.L.P. CARONE et al., Optically transparent membrane based on bacterial cellulose/polycaprolactone, Polímeros. Vol. 23, 2013.[5] Y. QAZI, G. WONGA, B. MONSONA et al. Corneal transparency: Genesis, maintenance and dysfunction, Brain Research Bulletin. Vol. 81, 2010.[6] G. HELENIUS, H. BÄCKDAHL, A. BODIN et al. In vivo biocompatibility of bacterial cellulose, Journal of Biomedical Materials Research. Vol. 76, 2006.[7] Y.M. MICHELACCI, Collagens and proteoglycans of the corneal extracellular matrix, Brazilian Journal of Medical and Biological Research. Vol. 36, 2003. Keywords: in vivo, Implant, Biocompatibility, polymer Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Biomaterials evaluation in animal models Citation: Queiroz PS, Valente FL, Sepúlveda RV, Eleotério RB, Barud HS, Carlo Reis EC and Borges AP (2016). Bacterial cellulose and bacterial cellulose/polycaprolactone composite as tissue substitutes in rabbit corneas. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.02183 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Paulo Victor S Queiroz Fabrício L Valente Rodrigo V Sepúlveda Renato B Eleotério Hernane S Barud Emily C Carlo Reis Andréa P Borges Google Paulo Victor S Queiroz Fabrício L Valente Rodrigo V Sepúlveda Renato B Eleotério Hernane S Barud Emily C Carlo Reis Andréa P Borges Google Scholar Paulo Victor S Queiroz Fabrício L Valente Rodrigo V Sepúlveda Renato B Eleotério Hernane S Barud Emily C Carlo Reis Andréa P Borges PubMed Paulo Victor S Queiroz Fabrício L Valente Rodrigo V Sepúlveda Renato B Eleotério Hernane S Barud Emily C Carlo Reis Andréa P Borges Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.