Currently, the development of biomaterials has focused on having a low Young’s modulus, biocompatibility, corrosion resistance, and antibacterial properties. Ti–Nb alloys have higher research value due to their excellent corrosion resistance and low Young’s modulus. In recent years, the antibacterial properties of materials have been enhanced by the addition of Ag and Cu. Therefore, the corrosion resistance and antibacterial properties of the Ti–12Nb–1Ag alloy formulated in the current study were investigated and compared to those of commonly used Ti alloys, G2 pure Ti (ASTM B348 CP Grade 2), and Ti–6Al–4V, via electrochemical and E. coli antibacterial tests. Meanwhile, we also carried out a microstructural analysis to investigate the composition of the alloy. The results were as follows: (1) The electrochemical test demonstrated that Ti–12Nb–1Ag had a higher corrosion resistance than Ti–6Al–4V, which is similar to the properties of pure Ti. (2) The E. coli antibacterial test demonstrated that the sterilization rate of Ti–12Nb–1Ag was higher than that of the Ti–6Al–4V alloy and pure Ti. (3) The microstructural analysis revealed that Ti–12Nb–1Ag had an acicular martensite structure, with nano-Ag precipitates observed. Based on the results of the E. coli antibacterial test and the principles of sterilization of nano-precipitates and Ag, we inferred that the nano-Ag precipitates of Ti–12Nb–1Ag enhanced the antibacterial properties of the newly developed biomaterial, which is, namely, the Ti–12Nb–1Ag alloy.

Titanium alloys are widely employed for the fabrication of biomedical devices. In this study, we designed and developed a Ti-5Al-2.5Cu alloy, which exhibited antibacterial properties. Microstructure and elemental analyses were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). We evaluated the alloy’s antibacterial properties using Escherichia coli in the plate-count method. The cytotoxicity was examined using the MG-63 cell response by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Microstructural analysis revealed that Ti-5Al-2.5Cu exhibited an equiaxed α’ martensite structure after short-term annealing. The heterogeneous and homogeneous α → α + Ti₂Cu phase transitions occurred at ~840 and 920 °C, respectively. The antibacterial property for Ti-5Al-2.5Cu was varied by volume fraction in the Ti₂Cu and Cu-rich phase, which was obtained using different heat treatments. The high volume fraction of the Ti₂Cu and Cu-rich phase was observed after long-term annealing at 720–840 °C and thus exhibited a higher antibacterial rate. The relationship between phase distribution and the antibacterial property could be satisfied by a positive linear regression equation. Cytotoxicity results showed that heat treatments at different temperatures for Ti-5Al-2.5Cu alloys had no effect on cell viability. The optimal heat treatment for Ti-5Al-2.5Cu alloy was annealing at 760 °C for 24 h. After, the alloy exhibited both promising antibacterial performance and good cytocompatibility.

Autologous bone remains the gold standard for surgical bone reconstruction but presents clinical challenges like donor site complications and operational difficulties. We investigate the osteogenic effects of a newly designed, ceramic and collagen-based, submicron-processed Flexible Hydrated-Hardening Bone Graft (FHBG), using both murine and human mesenchymal stem cells. We also compare the efficacy and safety of FHBG with a commercially available (CA) graft in New Zealand white rabbits with cranial bone defects. Rabbits were divided into three groups: no graft, CA, and FHBG, and evaluated using Micro-CT and histological analysis at three and six weeks post-surgery. Safety was assessed through blood samples. In vitro, FHBG promoted osteogenesis and upregulated osteogenic-associated genes in mesenchymal stem cells. In vivo, FHBG significantly enhanced bone regeneration, showing approximately 25% and 30% more improvement than the control at three and six weeks post-surgery. FHBG also had about half the residual content compared to the CA group. Blood analysis showed no hepatotoxicity or nephrotoxicity associated with the graft. FHBG significantly promotes bone regeneration both in vitro and in vivo. Additionally, FHBG has been demonstrated to be safe, with fewer residuals remaining in the body compared to currently in-use clinical bone grafts. This study validates the ability of the newly designed FHBG to facilitate osteogenesis in vitro and demonstrates its efficacy and safety in new bone formation in vivo. The lower residual material further suggests a reduced long-term impact and associated risk with the graft.