Effects of bio-inspired bioglass/collagen/magnesium composites on bone repair

Abstract

Bone disorders and fractures affect millions of people worldwide. In critical situations, proper healing may not happen which may lead to non-union fractures. Consequently, the development of new clinical approaches is necessary. In this context, the present work developed bioglass/collagen/magnesium composites in order to mimic natural bone, toward the enhancement of material mechanical properties, but keeping bioactivity and performance of bioglass and collagen. So, the aim of this investigation was to explore the biological outcomes of bioglass/collagen/magnesium composites over bone repair, using tibial defect in Wistar rats. For this purpose, histopathological, morphometrical and immunohistochemical analyses, as well as mechanical test, were performed after 15 and 45 days of the composites implantation in rats. Histopathological assessment indicated that the biocompatible composites degraded over time, leading to a progressive new bone formation from the border to the core of the defect. Immunohistochemistry showed that all groups presented runx-2 and Rank-L immunostaining, with improved runx-2 labeling for bioglass/magnesium compared to plain bioglass 45 days post-implantation. Mechanical tests of the tibiae indicated good mechanical properties of these Mg-based materials, but no statistical differences among groups were found. Additional studies should be done to confirm the outcomes of bioglass/collagen/magnesium on bone restoration, using different animal models and new balanced amounts of Mg (3 wt%< Mg\u2009<\u20095 wt%), as well as compromised, long-term and critical bone defect conditions.