Biocompatibiliry and biological performance of marine sponging associated to hydroxiapatite and bioglass used as bone grafts

Abstract

Fractures of difficult consolidation and large bone defects are associated with substantial disability to the affected individuals and the high socioeconomic costs, constituting a major challenge to the medical clinic. Thus, the developing technologies that promote bone repair and accelerate tissue regeneration are extremely important, decreasing costs and reducing morbidity and mortality related to complications during this process. Among them, can be cited the bioactive glasses and natural components from marine specimens, highlighting the spongin, the main organic component of the fibrous skeleton of sponges (Demospongiae class). Given this context, this study intends to develop spongin/Hydroxyapatite and sponging/Biosilicate composites as promising alternatives to accelerate bone repair. Thus, the objectives of this study are to characterize, evaluate the biocompatibility and biological effects of spongin from the sponge Aplysina caissara isolated or associated with hydroxyapatite or Biosilicate. For this purpose, the composites will characterize by scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). For the in vitro tests, the cytotoxicity and genotoxicity of the composites will be evaluated by Alamar Blue and Comet assay and using L929 and MC3T3 cells after 24, 72 and 120h. For the in vivo tests, 80 Wistar rats will be submitted to a surgical procedure in order to induce a tibial bone defect which will be filled with the biomaterial. The animals will be divided into 6 groups: control, hydroxyapatite, sponging, spongin/hydroxyapatite, Biosilicate and sponging/Biosilicate. Each experimental group will be divided into 2 subgroups, euthanized after 15 and 45 days post-surgery. To verify the effects of the biomaterials, the follow analysis will be performed: histopathology, morphometry, immunohistochemistry analysis, microtomography and biomechanical test. It is expected that the present project will contribute to the development of new biomaterials to be used as bone grafts, resulting in new approaches to the treatment of bone fractures. (AU)