Estudo por microtomografia computadorizada e histomorfometria do reparo ósseo com o uso do compósito de hidroxiapatita com alginato e gelatina

Abstract

Introduction: Critical bone defects represent a recurrent clinical problem. In these situations, bone repair capacity becomes limited and susceptible to errors. The use of synthetic biomaterials in the regeneration of bone tissue, as an option to grafts, reduces the risk of contamination and minimizes damage to healthy tissues. The hydroxyapatite (HA) combination with biodegradable polymers (collagen, alginate, gelatin) is a promising strategy for the development of optimal bone replacements. Objectives: To contextualize the use of alginate and gelatin composites applied to the repair of bone tissue (article 1). Evaluate computed microtomography (μCT) and histomorphometry of critical bone defect repair, after the implantation of alginate and gelatin hydroxyapatite composite (HAAlgGel), comparing it to the Bio-Oss ® (article 2). Materials and Methods: This was a systematic review of the literature, searches were carried out in the PubMed database, inclusion and exclusion criteria were used and articles published between 2013 and 2018 in the English language (article 1). The sample consisted of 24 male adult Wistar rats randomly assigned to compose 3 groups with 08 animals each: HAAlgGel group - critical bone defect filled with granules of the hydroxyapatite composite with 1% alginate and 1% gelatin ; Bio-Oss® group - critical bone defect filled with BioOss® granules; Control group - empty critical bone defect. Samples were evaluated by μCT at biological points: 1 day (base line), 15 days, 45 days and 90 days and histomorphometric analysis at 90 days (article 2). Results: 16 were selected, being 15 original articles and 1 literature review (article 1). The morphometric analysis by μCT showed that the HAAlgGel group maintained the percentage of bone tissue constant throughout the study; already in the Bio-Oss® and Control groups, this percentage increased over the period evaluated. Histological analysis revealed border-restricted bone neoformation in all experimental groups at 90 days (article 2). Conclusion: It is concluded that the association of the alginate or gelatin composite with other biomaterials, especially hydroxyapatite, may potentiate its effect on bone repair (article 1). The biomaterials did not favor the regeneration of the critical bone defect. Prevalence of fibrosis repair in all groups evaluated. The μCT made it possible to follow the bone repair throughout the study, without the need for animal sacrifice, in several biological points (article 2).