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Background: Excessive inflammation is a major cause of implant failure. The surface morphology, hydrophilicity, and loading of biomaterials are major properties modulating anti-inflammatory macrophage activation. This paper investigates the regulatory effects of modifying the surface of Titanium dioxide nanotubes (TNTs) with graphene oxide (GO) on the polarization of mouse monocyte macrophages (RAW264.7). Methods: TNT was produced by the anodic oxidation of titanium. GO was subsequently electrodeposited on the TNT to obtain a TNT–GO composite. The samples were characterised through scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction. RAW264.7 cells were separately seeded onto the surface of three groups of samples: pure Ti, TNT, and TNT–GO. Under the condition of lipopolysaccharide stimulation, the influence of the sample surfaces on the gene expression profiles was investigated through RNA sequence analysis. In addition, cell spreading was observed through SEM, cell adhesion and proliferation were analysed using the CCK8 assay, and the expression of inflammation-related factors was investigated by ELISA and cellular immunofluorescence staining. The production of reactive oxygen species (ROS) in the RAW264.7 cells on the surface of the three groups was detected via immunofluorescence staining. Results: The CCK8 results indicated that the adhesion and proliferation of the RAW264.7 cells were reduced on the TNT and TNT–GO surfaces. ELISA results revealed significant differences in the pro-inflammatory factors tumour necrosis factor-α and interleukin-6 secretion among the three groups at 24 h (p < 0.05). The secretion of pro-inflammatory factors significantly reduced and the expression of anti-inflammatory factor IL-10 increased on the TNT and TNT–GO surfaces. The RNA sequencing, ELISA, and cell immunofluorescence staining test results suggested that the inflammatory response of M1 polarization was reduced and the M2 polarization of macrophages was induced on the TNT–GO surface, which may be attributed to the reduction in ROS production. Conclusions: Under lipopolysaccharide stimulation, the inflammatory response of the RAW264.7 cells was reduced and the M2 polarization of macrophages was promoted on the TNT–GO surface, which may be caused by the reduced ROS production. Consequently, the designed TNT–GO material is promising for implants owing to its excellent inflammation regulation ability. [ABSTRACT FROM AUTHOR]

The immunomodulatory role of monocytes is essential for tissue healing and can influence the osseointegration of implanted materials. Properties such as the surface structure, hydrophilicity, and roughness of the implanted materials can modulate monocyte–macrophage function. In this study, we characterized material-hydrogenated TiO2 nanotubes (H-TNT) with superhydrophilic surfaces to investigate the effect of H-TNT on macrophage polarization and osseointegration. H-TNT were prepared by anodic oxidation and hydrogenation and used in the experimental group, while TNT and smooth pure Ti were employed in the control groups. RAW264.7 cells were selected to observe the immunomodulatory effect of these samples. The cell morphology was observed via scanning electron microscopy, and cytokine expression was detected using an enzyme-linked immunosorbent assay and immunofluorescence staining. After 24 hr of cultivation, the macrophage-conditioned medium was collected and used for indirect coculture with MC3T3-E1 cells. The morphology of MC3T3-E1 cells was observed using fluorescence staining. Cell adhesion and proliferation were measured using the Cell Counting Kit-8 assay. Alkaline phosphatase activity measurement, alizarin red staining, calcium quantification, and reverse transcription polymerase chain reaction were performed to assess the osteogenic differentiation of MC3T3-E1 cells. The results showed that H-TNT promoted the M2-type polarization of macrophages, which in turn influenced the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. These materials can serve as useful candidates for bone implants because they activate macrophages to produce a favorable osteoimmunomodulatory microenvironment. [ABSTRACT FROM AUTHOR]

Titanium-based implants are often utilized in oral implantology and craniofacial reconstructions. However, the biological inertness of machined titanium commonly results in unsatisfactory osseointegration. To improve the osseointegration properties, we modified the titanium implants with nanotubular/superhydrophilic surfaces through anodic oxidation and thermal hydrogenation and evaluated the effects of the machined surfaces (M), nanotubular surfaces (Nano), and hydrogenated nanotubes (H-Nano) on osteogenesis and osseointegration in vitro and in vivo. After incubation of mouse bone marrow mesenchymal stem cells on the samples, we observed improved cell adhesion, alkaline phosphatase activity, osteogenesis-related gene expression, and extracellular matrix mineralization in the H-Nano group compared to the other groups. Subsequent in vivo studies indicated that H-Nano implants promoted rapid new bone regeneration and osseointegration at 4 weeks, which may be attributed to the active osteoblasts adhering to the nanotubular/superhydrophilic surfaces. Additionally, the Nano group displayed enhanced osteogenesis in vitro and in vivo at later stages, especially at 8 weeks. Therefore, we report that hydrogenated superhydrophilic nanotubes can significantly accelerate osteogenesis and osseointegration at an early stage, revealing the considerable potential of this implant modification for clinical applications. [ABSTRACT FROM AUTHOR]

We successfully fabricated the hydrogenated TiO2 nanotubes/Ti foil (H-TNTs/f-Ti) composite via one-step anodization and two-step annealing. H-TNTs/f-Ti composite had a higher visible light-induced photoelectric response and more hydroxyl functional groups compared with Ti foil and unmodified TiO2 nanotubes/Ti foil composite, which contributed to limiting the proliferation of Streptococcus mutans and Porphyromonas gingivalis, promoting the proliferation of MC3T3-E1 cell on the hydroxylated surface, and improving the biocompatibility with osteogenic cells. Our study provides a simple and effective method for significantly improving dental implant efficacy. [ABSTRACT FROM AUTHOR]

Macrophages are attracting increasing attention in promoting implant-mediated osteogenesis by modulating the microenvironment of the implant site. Biomaterial surface properties including topography and wettability regulate macrophage responses to influence tissue repair. The objective of our present study was to investigate the effects of hydrogenated titanium dioxide nanotube surfaces on the immune response of macrophages in vitro. Hydrogenated titanium dioxide nanotubes (TNTs) were synthesized on Ti surfaces by anodic oxidation and hydrogenation to form super-hydrophilic nanotubular surfaces. Macrophages were seeded directly onto three substrates (hydrogenated TNTs (H2-TNTs), air-annealed TNTs, and commercially pure Ti substrates) and grown under standard or lipopolysaccharide-stimulated culture conditions. Cell proliferation and viability were evaluated by Cell Counting Kit-8 and live/dead staining at 24 and 48 h. Secretion and expression of pro- and anti-inflammatory cytokines were evaluated at 24 and 48 h to determine whether the surfaces elicited differential macrophage behaviors. Gene expression of the M1/M2 surface markers of macrophages was analyzed to assess the effect of the H2-TNT surface on macrophage polarization. The results showed that hydrogenation of the TNT surface resulted in a super-hydrophilic substrate, which exhibited markedly improved wettability attributable to the formation of oxygen vacancies in the nanotubes. The H2-TNT group induced a significantly lower macrophage proliferation rate and up-regulated anti-inflammatory cytokines (interleukin-10, bone morphogenetic protein-2, and transforming growth factor-β1) irrespective of lipopolysaccharide stimulation, while alleviating the secretion of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-6, nitric oxide, and macrophage chemotactic protein-1) induced by lipopolysaccharide. Moreover, the H2-TNT surface elicited up-regulated gene expression of M2 surface markers and down-regulation of M1 surface markers. We concluded that the hydrogenated TNT surface modulated macrophage immune responses, which could be useful in accelerating inflammation resolution and facilitating tissue repair. [ABSTRACT FROM AUTHOR]

Photocatalysis has a broad prospect for generating H 2 and reactive oxygen species. In this study, porous nanotubular g-C 3 N 4 /TiO 2 photocatalysts were obtained via electrospinning combined with an innovative vapor deposition approach. The waste foam was used as the precursor material for TiO 2 nanotubes, reducing production cost and benefiting resource recovery. The modification of g-C 3 N 4 onto TiO 2 nanotubes provided extensive active sites with an increased specific surface area and produced the heterojunction to improve charge separation. The g-C 3 N 4 /TiO 2 nanotubes displayed remarkable photocatalytic effects in the degradation of organic dye with a removal efficiency of 93.4% and H 2 evolution reaction performing at 4122 μmol·g−1·h−1 under simulated sunlight. Photocatalytic activation product analyses and density functional theory (DFT) calculations demonstrated a possible photogenerated carriers transfer pathway. This work provides a way to prepare multifunctional porous nanotubes using a facile synthesis method from abandoned resources with implications for environmental remediation and hydrogen generation. [Display omitted] • Waste foam was used as the precursor material for preparing TiO 2 nanotubes. • Porous nanotubular g-C 3 N 4 /TiO 2 photocatalysts were obtained via an innovative vapor deposition approach. • g-C 3 N 4 /TiO 2 displayed remarkable photocatalytic effects for pollutant degradation and hydrogen generation. • Mechanism of photon-generated charges separation and transfer was discussed. [ABSTRACT FROM AUTHOR]

A new hydrogel based on a substituted phenyl glucoside with a Schiff base in the aglycon was synthesized, and the self-assembling characteristics was studied. FTIR spectra, UV–vis absorption spectra and X-ray diffraction (XRD) revealed that π–π interactions between the Schiff base moieties, hydrogen bonds, and the interdigitated interactions between hydrophobic chains had effects on the formation of the self-assembling hydrogel. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) observation showed that the three-dimensional hydrogel network was constructed from nanotubes with inner diameters of ca. 75 nm and wall of ca. 20 nm. [Copyright &y& Elsevier]

The soft tissue sealing at the transmucal portion of implants is vital for the long-term stability of implants. Hydrogenated titanium nanotubes (H2-TNTs) as implant surface treatments were proved to promote the adhesion of human gingival fibroblasts (HGFs) and have broad usage as drug delivery systems. Bovine serum albumin (BSA) as the most abundant albumin in body fluid was crucial for cell adhesion and was demonstrated as a normal loading protein. As the first protein arriving on the surface of the implant, albumin plays an important role in initial adhesion of soft tissue cells, it is also a common carrier, transferring and loading different endogenous and exogenous substances, ions, drugs, and other small molecules. The aim of the present work was to investigate whether BSA-loaded H2-TNTs could promote the early adhesion of HGFs; H2-TNTs were obtained by hydrogenated anodized titanium dioxide nanotubes (TNTs) in thermal treatment, and BSA was loaded in the nanotubes by vacuum drying; our results showed that the superhydrophilicity of H2-TNTs is conducive to the loading of BSA. In both hydrogenated titanium nanotubes and non-hydrogenated titanium nanotubes, a high rate of release was observed over the first hour, followed by a period of slow and sustained release; however, BSA-loading inhibits the early adhesion of human gingival fibroblasts, and H2-TNTs has the best promoting effect on cell adhesion. With the release of BSA after 4 h, the inhibitory effect of BSA on cell adhesion was weakened. [ABSTRACT FROM AUTHOR]

Background: Modified titanium substrates with titanium dioxide nanotubes have broad usage as implant surface treatment and as drug- delivery systems. Their performance in most of these applications is highly dependent on there morphology. Macrophage behavior was thought to be regulated by nanostructured titanium which has been considered as a very promising candidates for dental implants. Aim/Hypothesis: To investigate effects of hydrogenated TiO2 nanotubes on macrophage behavior, secretion and expression of pro- inflammatory cytokines and chemokines. Material and Methods: Macrophage- like J744A.1 cells were cultured on three types of Ti surface- hydrogenated TiO2 nanotubes, unmodified TiO2 nanotubes, and Ti substrates (as control) for 4, 24 and 48 hours. Macrophage adhesion and proliferation were assessed using CCK-8 assay. Levels of pro-inflammatory cytokines (TNF- a, IL- 1b and IL- 6) and chemokines (MCP-1 and MIP-1a) secreted into the supernatant were measured using the Cytometric Bead Arrays kit. TNF-a, MCP-1 and MIP- a gene expression were quantitatively analysed by real- time PCR. Results : These show that TiO2 nanotube surfaces, especially hydrogenated TiO2 nanotubes, benefited macrophage adhesion and prolifera-tion, and reduced protein secretion and mRNA expression of pro- inflammatory cytokines and chemokines. Conclusions and Clinical Implications : TiO2 nanotube surfaces, especially hydrogenated TiO2 nanotubes, reduced inflammatory response in vitro, which might induce rapid osseointegration in implants with hydrogenated TiO2 nanotube surfaces in vivo. [ABSTRACT FROM AUTHOR]

Background : Modified titanium substrates with titanium dioxide nanotubes have broad usage as implant surface treatment and drug delivery system. Their performance in most of these application is highly dependent on their morphology, nanotube dimension, and wettability. Aim/Hypothesis : To improve the drug-loading capacity and accelerate bone integration with titanium, in this study, we hydrogenated anodized titanium dioxide nanotubes (TNTs) by a thermal treatment. Material and Methods: Three groups were examined, namely- hydrogenated TNTs (H2-TNTs, test), unmodified TNTs (air- TNTs, control), and Ti substrates (Ti control). Results : Our results showed that oxygen vacancies were present in all the nanotubes. The quantity of -OH groups greatly increased after hydrogenation. Furthermore, the protein adsorption and loading capacity of the H2- TNTs were considerably enhanced as compared with the properties of the air-TNTs ( P < 0.05). Additionally, time-of-flight secondary ion mass spectrometry (TOF- SIMS) was used to investigate the interactions of TNTs with proteins. During the protein- loading process, the H2- TNTs not only enabled rapid protein adsorption, but also decreased the rate of protein elution compared with that of the air-TNTs. We found that the H2-TNTs exhibited better biocompatibility than the air-TNT and Ti groups. Both cell adhesion activity and alkaline phosphatase activity were significantly improved toward MG-63 human osteoblast-like cells as compared with the control groups (P < 0.05). Conclusions and Clinical Implications : Therefore, we conclude that hydrogenated TNTs can greatly improve the loading capacity of bioactive molecules and MG-63 cell proliferation. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a novel method for the preparation of copper sulfide (CuS) nanotubes using hydrogel based on N-lauroylalanine as template under mild condition. The resulting samples are examined by transmission electron microscopy (TEM) FT-IR spectroscopy, X-ray powder diffraction (XRD), UV–vis absorption spectroscopy. It is found that the intermolecular hydrogen bonds play an important role on the formation of the hydrogel and the Cu2+ coordination gel. The formation process of CuS nanotube is also discussed. [Copyright &y& Elsevier]

• Superhydrophilic nanostructure was fabricated for improving soft tissue sealing. • The properties of the surface regulate the behavior of human gingival fibroblasts. • FAK/integrin-mediated adhesion seemed to be induced by the hydrogenated surface. Soft tissue integration is critical for the long-term retention of dental implants. The surface properties including topography and wettability can impact soft tissue sealing. In our work, a thermal hydrogenation technique was applied to modify anodized titanium dioxide nanotubes (TNTs). However, the effects of the hydrogenated surface on soft-tissue cells remain unclear. The aim of the present study was to investigate the bioactivities of human gingival fibroblasts (HGFs) on structured surfaces, which determine the early formation of soft tissue sealing. Three groups were examined: commercially pure titanium (Ti), anodized TNTs (air-TNTs) and hydrogenated TNTs (H 2 -TNTs). Scanning electron microscopy showed the nanotubular topography on the titanium surfaces after anodization. Then, hydrogenation ensured that the H 2 -TNTs were superhydrophilic with a contact angle of 3.5 ± 0.8°. In vitro studies such as cell adhesion assays, cell morphology, immunocytochemistry, wound healing assays, real-time PCR and enzyme-linked immunosorbent assays displayed enhanced adhesion, migration, relative gene expression levels, and extracellular matrix synthesis of the HGFs on H 2 -TNTs. Interestingly, focal adhesion kinase activation and integrin-mediated adhesion seemed to be induced by the H 2 -TNT surface. Our results revealed that a superhydrophilic nanostructure modified by anodization and hydrogenation can improve the bioactivity of HGFs and connective tissue regeneration, which will further promote and expand the application of titanium dioxide nanotubes in dental implants. [ABSTRACT FROM AUTHOR]