Ni-Ti-O nanoporous film with pore diameters of 60–75nm are produced anodically on NiTi in ethylene glycol containing 5–10vol% H2O and 0.15–0.3M NaCl at 10–20V. The film fabricated in the ...NaCl-containing electrolyte are much thinner than those prepared in the HCl-containing electrolyte under similar experimental conditions, implying proper amount of H+ in the electrolyte accelerates formation of the nanopores. Moreover, the experimental conditions to grow Ni-Ti-O nanoporous film on NiTi are not proper for pure Ti and Ni. The film of 1.9μm in thickness exhibits good cytocompatibility thus is suitable for biomedical applications.
•Ni-Ti-O nanoporous film (NPF) is fabricated by anodizing NiTi alloy.•The electrolyte to generate the NPF is ethylene glycol containing H2O and NaCl.•Presence of H+ in the electrolyte may accelerate the growth of the NPF.•The conditions for growth of the NPF on NiTi alloy are not proper for pure Ti and Ni.•The NPF of 1.9μm in thickness exhibit good cytocompatibility.
Bacterial infection and loosening of orthopedic implants remain two disastrously postoperative complications. Angiogenesis is critical important to facilitate implant osseointegration in vivo. TiO2 ...nanotubes arrays (NTAs) with proper dimensions possess good osseointegration ability. Accordingly, the present work incorporated copper (Cu) into TiO2 NTAs (Cu-Ti-O NTAs) to enhance their antibacterial ability and angiogenesis activity, which was realized through anodizing magnetron-sputtered TiCu coatings with different Cu contents on pure titanium (Ti). Our results show ordered Cu-Ti-O NTAs can be produced under proper Cu content (<15.14%) in TiCu coatings. The NTAs possess excellent long-term antibacterial ability against Staphylococcus aureus (S. aureus), which may be ascribed to sustained release of Cu2+. The cytotoxicity of Cu-Ti-O NTAs to endothelial cells (ECs) could be negligible and can even promote cell proliferation as revealed by live/dead staining and MTT. Meanwhile, Cu-Ti-O NTAs can up-regulate nitric oxide (NO) synthesis and vascular endothelial growth factors (VEGF) secretion of ECs on the sample surfaces compared with that of pure TiO2 NTAs (control). Furthermore, the angiogenic activity is also enhanced in ionic extracts of Cu-Ti-O NTAs compared with the control. The excellent long-term antibacterial ability and favorable angiogenic activity render Cu-Ti-O NTAs to be promising implant coatings.
•Cu-Ti-O NTAs possess long-term antibacterial ability against Staphylococcus aureus.•Cu-Ti-O NTAs can up-regulate nitric oxide synthesis and vascular endothelial growth factors secretion of endothelial cells.•Cu-Ti-O NTAs can enhance in vitro angiogenesis activity of endothelial cells.
Stent implantation has become one of the most widely used methods for the treatment of cardiovascular diseases. However, endothelial dysfunction and abnormal inflammatory response following ...implantation may lead to delayed re-endothelialization, resulting in vascular restenosis and stent thrombus. To address the concerns, we constructed nanospindles composed of TiO2 and Ti4Ni2O through hydrothermal treatment of amorphous Ni-Ti-O nanopores anodically grown on NiTi alloy. The results show the treatment can significantly improve hydrophilicity and reduce Ni ion release, essentially independent of hydrothermal duration. The nanospindle surfaces not only promote the expression of endothelial functionality but also activate macrophages to induce a favorable immune response, downregulate pro-inflammatory M1 markers and upregulate pro-healing M2 markers. Moreover, nitric oxide (NO) synthesis, VEGF secretion, and migration of endothelial cells are enhanced after cultured in macrophage conditioned medium. The nanospindles thus are promising as vascular stent coatings to promote re-endothelization.
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•The nanospindles can be fabricated by hydrothermal treatment of Ni-Ti-O nanopores.•Nanospindle surfaces directly upregulate EC functionality.•Nanospindle surfaces can upregulate EC functionality through immunomodulation.
In the present work, nickel-titanium-oxygen nanopores with different length (0.55–114 μm) were anodically grown on nearly equiatomic nickel-titanium (NiTi) alloy. Length-dependent corrosion behavior, ...nickel ion (Ni2+) release, cytocompatibility, and antibacterial ability were investigated by electrochemical, analytical chemistry, and biological methods. The results show constructing nanoporous structure on the NiTi alloy improve its corrosion resistance. However, the anodized samples release more Ni2+ than that of the bare NiTi alloy, suggesting chemical dissolution of the nanopores rather than electrochemical corrosion governs the Ni2+ release. In addition, the Ni2+ release amount increases with nanopore length. The anodized samples show good cytocompatibility when the nanopore length is <11 μm. Encouragingly, the length scale covers the one (1–11 μm) that the nanopores showing favorable antibacterial ability. Consequently, the nanopores with length in the range of 1–11 μm are promising as coatings of biomedical NiTi alloy for anti-infection, drug delivery, and other desirable applications.
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•Ni-Ti-O nanopores with different length (0.55–114 μm) were anodically grown on NiTi alloy.•The release of Ni2+ from the nanopores is governed by chemical dissolution.•The release amount of Ni2+ increases with nanopore length.•The nanopores with proper length (1–11 μm) show good cytocompatibility and antibacterial ability.
The present work reports on the hydrothermal synthesis of nanosheets on biomedical NiTi alloy in pure water. The results show rhombohedral NiTiO
nanosheets with thickness of 6 nm can be grown at ...200 °C. Hydrothermal treatment enhances the corrosion resistance of the NiTi alloy. 30 min of the treatment significantly reduces Ni ion release, while prolonged hydrothermal time results in increased Ni ion release because of the growth of the nanosheets with large specific surface area. Excitingly, the nanosheets can well support cell growth, which suggests the release amount can be well tolerated. Good corrosion resistance and cytocompatibility combined with large specific surface area render the nanosheets promising as safe and efficient drug carriers of the biomedical NiTi alloy.
The present work reports on the hydrothermal synthesis of nanosheets on biomedical NiTi alloy in pure water. The results show rhombohedral NiTiO3 nanosheets with thickness of 6 nm can be grown at ...200 °C. Hydrothermal treatment enhances the corrosion resistance of the NiTi alloy. 30 min of the treatment significantly reduces Ni ion release, while prolonged hydrothermal time results in increased Ni ion release because of the growth of the nanosheets with large specific surface area. Excitingly, the nanosheets can well support cell growth, which suggests the release amount can be well tolerated. Good corrosion resistance and cytocompatibility combined with large specific surface area render the nanosheets promising as safe and efficient drug carriers of the biomedical NiTi alloy.
•NiTiO3 nanosheets were hydrothermally synthesized on NiTi alloy in pure water at 200 °C.•Hydrothermal treatment enhances the corrosion resistance of the NiTi alloy.•The nanosheets can well support cell growth.
In the present work, nickel-titanium-oxygen nanopores with different length (0.55–114 μm) were anodically grown on nearly equiatomic nickel-titanium (NiTi) alloy. Length-dependent corrosion behavior, ...nickel ion (Ni2+) release, cytocompatibility, and antibacterial ability were investigated by electrochemical, analytical chemistry, and biological methods. The results show constructing nanoporous structure on the NiTi alloy improve its corrosion resistance. However, the anodized samples release more Ni2+ than that of the bare NiTi alloy, suggesting chemical dissolution of the nanopores rather than electrochemical corrosion governs the Ni2+ release. In addition, the Ni2+ release amount increases with nanopore length. The anodized samples show good cytocompatibility when the nanopore length is <11 μm. Encouragingly, the length scale covers the one (1–11 μm) that the nanopores showing favorable antibacterial ability. Consequently, the nanopores with length in the range of 1–11 μm are promising as coatings of biomedical NiTi alloy for anti-infection, drug delivery, and other desirable applications.
Anodization is used to fabricate Ni–Ti–O nanotube (NT) electrodes for non-enzymatic glucose detection. The morphology, microstructure and composition of the materials are characterized by field ...emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Our results show amorphous and highly ordered NTs with diameter of 50nm, length of 800nm, and Ni/Ti ratio (at %) of 0.35 can be fabricated in ethylene glycol electrolyte supplemented with 0.2 wt.% NH4F and 0.5 vol.% H2O at 30°C and 25V for 1h. Electrochemical experiments indicate that at an applied potential of 0.60V vs. Ag/AgCl, the electrode exhibits a linear response window for glucose concentrations from 0.002mM to 0.2mM with a response time of 10s, detection limit of 0.13μM (S/N=3), and sensitivity of 83μAmM−1cm−2. The excellent performance of the electrode is attributed to its large specific area and fast electron transfer between the NT walls. The good electrochemical performance of the Ni–Ti–O NTs as well as their simple and low-cost preparation method make the strategy promising in non-enzymatic glucose detection.
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•Highly ordered Ni–Ti–O nanotubes have been fabricated by one-step anodization.•We find H2O contents in the electrolyte is critical to successful fabrication of the NTs.•The Ni–Ti–O nanotubes are ideal electrode materials for non-enzymatic glucose detection.
Human serum albumin （HSA） is an abundant protein in plasma that can bind and transport many small molecules, and the corresponding affinity-controlled drug delivery shows great advantage in the ...biological system. Peptide SA06 is a reported ligand comprising 20 amino acids, and is known to non-covalently bind with HSA to extend the lifetime and improve the pharmacokinetic performance. The structural information of the HSA-peptide complex is keen for obtainingmolecular insight of the binding mechanism. We studied the secondary structural change and structure-affinity relations of Peptide SA06 with HSA by using circular dichroism （CD） spectroscopy in solution. Noticeable allosteric effect can be identified by compositional increase of a-helix structures when the peptide was co-incubated with HSA. Furthermore, the equilibrium dissociation constant of Peptide SA06 with HSA can be determined by CD-baged method. This work provides structural evidence on the allosteric interaction between peptide ligand and HSA, and sheds light on optimization of therapeutic properties in the affinity-controlled delivery systems.
In the present work, nickel-titanium-oxygen nanopores with different length (0.55-114 μm) were anodically grown on nearly equiatomic nickel-titanium (NiTi) alloy. Length-dependent corrosion behavior, ...nickel ion (Ni
) release, cytocompatibility, and antibacterial ability were investigated by electrochemical, analytical chemistry, and biological methods. The results show constructing nanoporous structure on the NiTi alloy improve its corrosion resistance. However, the anodized samples release more Ni
than that of the bare NiTi alloy, suggesting chemical dissolution of the nanopores rather than electrochemical corrosion governs the Ni
release. In addition, the Ni
release amount increases with nanopore length. The anodized samples show good cytocompatibility when the nanopore length is <11 μm. Encouragingly, the length scale covers the one (1-11 μm) that the nanopores showing favorable antibacterial ability. Consequently, the nanopores with length in the range of 1-11 μm are promising as coatings of biomedical NiTi alloy for anti-infection, drug delivery, and other desirable applications.
