Efficacy of Streptomyces achromogenes MAA01-influenced hydroxyapatite/graphene oxide nanocomposites for bone...

This study investigates hydroxyapatite (HAp) nanocomposites infused with Streptomyces achromogenes MAA01-pretreated graphene oxide (GO) for bone tissue engineering. Hydrothermally synthesized HAp/GO (HH-G) nanocomposites showed rod with sheetlike structures with nano level crystallite size, and appropriate bioactivity and degradability. Raman spectroscopy confirmed the successful reduction of GO to reduced graphene oxide (rGO), enhancing antibacterial properties and cellular interactions. Among various formulations, the HH-G0.5 (1:0.5 ratio) nanocomposite demonstrated superior performance, promoting in vitro osteoblast proliferation, upregulating osteogenic gene markers (COL1, OCN, and ALP) in 2 folds, and exhibiting an appropriate Ca/P ratio (1.67) for optimal bone mineralization, as confirmed by in vivo analysis. The Streptomyces MAA01 pre-treatment notably improved antioxidant capacity and maintained a non-toxic profile. Histopathological evaluations showed non-significant toxicity or organ accumulation in liver and kidney tissues. In vivo implantation studies in Wistar rats further confirmed that HH-G0.5 significantly enhanced bone regeneration compared to pure GO or HAp. These results suggest that HH-G0.5 is a promising and safe and highly effective candidate for future clinical applications in bone tissue regeneration and repair.