Implementation of nanographene oxide combined with mineral trioxide aggregate and hydroxyapatite biopolymer in regeneration of critical-sized bone defect in rats.

Critical-sized bone defects (CSBDs) are causing a significant challenge in orthopedic surgery for their inability to heal spontaneously, demanding innovative biomaterials to enhance bone formation. Current therapies, as autografts and allografts, are restricted by donor site morbidity and immune rejection. The current study presents a novel, biocompatible composite material formed of nano-graphene oxide (nGO), mineral trioxide aggregate (MTA), and hydroxyapatite (HAp) and designed to synergistically control the unique characters of each component. The novelty of this composite is due to its composition as it formed via the combination of nGO for enhancement of the mechanical strength and the cell proliferation, MTA for its higher bioactivity and its ability for cement formation, while the HAp having optimum biocompatibility and osteoconductivity, this synergistic interaction was not previously explored for CSBD repair. The current study utilized a rat model of critical-sized radial bone defects. The nGO/MTA/HAp composite was manufactured by consuming a modified Hummer’s method for nGO, combined with commercially available MTA and HAp. Radiographic and computed tomography (CT) evaluation at 2-, 4-, and 8-weeks post-operation elaborating the progressive bone formation in the treated group compared to minimal changes in the untreated group. Histopathological examination demonstrated strong composite integration, massive cellular infiltration, and strong signs of osteoblast differentiation, causing approximately 75–85% defect closure at the 8th week. The current study highlights the potential of the nGO/MTA/HAp composite as a biocompatible and osteoinductive composite for CSBD repair, presenting enhanced mechanical strength, bioactivity, and osteoconductivity.