Abstract

The incorporation of nanoparticles into metallic biomaterials has been recognized as a significant approach to improve their bioactivity for biomedical applications. In this study, friction stir processing (FSP) was employed to incorporate TiO 2 nanoparticles as bioactive reinforcement into the β titanium alloy Ti–35Nb–2Ta–3Zr (TNTZ) matrix to construct an integrated micro-nano composite layer. The effect of different TiO 2 contents on the osteogenic capacity of rat bone marrow stromal stem cells (BMSCs) was studied. The TiO 2 /TNTZ composite layer exhibited a refined grain structure with a mean grain size of approximately 10 μm and a characteristic surface morphology of pronounced peaks and valleys with enhanced R Skw and R Kur values. Moreover, TiO 2 /TNTZ significantly promoted the adhesion, proliferation, and spreading of BMSCs, upregulated the expression of genes related to osteogenesis ( ALP and Runx2 ) up to nearly 1.5 times, and enhanced the expression of ALP and OCN ( P  < 0.05). The novel FSPed TiO 2 /TNTZ micro-nano composite possesses excellent surface characteristics and favorable biological activities, manifesting vast potential for upcoming clinical applications.