Enhanced physicochemical and biological properties of C/Cu dual ions implanted medical titanium.

It is increasingly popular for titanium and its alloys to be utilized as the medical implants. However, their bio-inert nature and lack of antibacterial ability limit their applications. In this work, by utilizing plasma immersion ion implantation and deposition (PIII&D) technology, the titanium surface was modified by C/Cu co-implantation. The mechanical property, corrosion resistance, antibacterial ability and cytocompatibility of modified samples were studied. Results indicate that after C/Cu co-implantation, copper nanoparticles were observed on the surface of titanium, and titanium carbide existed on the near surface region of titanium. The modified surface displayed good mechanical property and corrosion resistance. The Cu/C galvanic corrosion existed on the titanium surface implanted by C/Cu dual ions, and release of copper ions can be effectively controlled by the galvanic corrosion effect. Moreover, improved antibacterial performance of titanium surface can be achieved without cytotoxicity.

Dose-response relationships between copper and its biocompatibility/antibacterial activities.

BACKGROUND: Copper has already been widely used in the modification of biomaterials because it possesses multifunctional biological effects like osteogenic, angiogenic and antibacterial activities. However, it is still not clear how different cell lines and bacteria will respond to different concentrations of Cu2+, which is very critical to the application of copper-doped implants. METHODS: This study aimed to explore the dose-response relationships of Cu2+ and its biological effects in vitro. Rat bone marrow mesenchymal stem cell (rBMSCs), mouse osteoblastic cell line (MC3T3-E1), and human umbilical vein endothelial cells (HUVECs) were used to evaluate cellular behaviors. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were used to evaluate bacterial behaviors. RESULTS: Results showed that the HUVECs exhibited significantly higher tolerance to copper ions than MC3T3-E1 and rBMSCs. The IC50 values of copper for HUVECs, MC3T3-E1 and HUVECs were approximated to 327.9 µM, 134.6 µM, and 0.7 µM, respectively. Besides, the threshold concentration of copper for effective inhibition against bacteria growth is 37 µM. When the concentration exceeded the threshold value, antibacterial activity could increase dramatically. CONCLUSIONS: These results altogether establish a technological foundation for the application of copper-doped biomaterials in bone growth and remodeling.

Vacuum Thermal Treated Ni-CeO2/SBA-15 Catalyst for CO2 Methanation.

Ni-CeO2/SBA-15-V catalyst was prepared by the impregnation method with vacuum thermal treatment and used for CO2 methanation reaction. Compared with Ni-CeO2/SBA-15-air catalyst with thermal treatment in air, the reduced Ni-CeO2/SBA-15-V catalyst with vacuum thermal treatment exhibited higher Ni dispersion and smaller Ni particle size. In CO2 methanation reaction, the Ni-CeO2/SBA-15-V catalyst was more active and selective than the Ni-CeO2/SBA-15-air catalyst. The good activity and selectivity of Ni-CeO2/SBA-15-V catalyst should be due to highly dispersed Ni in contact with small CeO2 particles.

Synergistic Effects of N/Cu Dual Ions Implantation on Stimulating Antibacterial Ability and Angiogenic Activity of Titanium.

Titanium and its alloys have been commonly used as implant materials. However, the inherent bioinert nature hinders its good osseointegration which limits its permanent clinical applications. In this work, nitrogen (N) and copper (Cu) dual ions were implanted into titanium by plasma immersion ion implantation and deposition (PIII&D) technology. The corrosion resistance, mechanical property, antibacterial ability, and angiogenic activity of the modified titanium surfaces were investigated. Experimental results show that titanium nitride (TiN) film embedded with Cu nanoparticles (Cu NPs) forms on the surface of the N/Cu dual ions implanted titanium. The N/Cu dual ions implanted titanium exhibits excellent corrosion resistance and mechanical property. The galvanic corrosion of Cu/TiN can effectively control copper ion release to enhance the antibacterial and angiogenic performances of the Ti surface.