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Molecules (Basel, Switzerland) Oct 2022Nanotechnology has acquired significance in dental applications, but its safety regarding human health is still questionable due to the chemicals utilized during various...
Nanotechnology has acquired significance in dental applications, but its safety regarding human health is still questionable due to the chemicals utilized during various synthesis procedures. Titanium nanoparticles were produced by three novel routes, including Bacillus subtilis, Cassia fistula and hydrothermal heating, and then characterized for shape, phase state, size, surface roughness, elemental composition, texture and morphology by SEM, TEM, XRD, AFM, DRS, DLS and FTIR. These novel titanium nanoparticles were tested for cytotoxicity through the MTT assay. L929 mouse fibroblast cells were used to test the cytotoxicity of the prepared titanium nanoparticles. Cell suspension of 10% DMEM with 1 × 104 cells was seeded in a 96-well plate and incubated. Titanium nanoparticles were used in a 1 mg/mL concentration. Control (water) and titanium nanoparticles stock solutions were prepared with 28 microliters of MTT dye and poured into each well, incubated at 37 °C for 2 h. Readings were recorded on day 1, day 15, day 31, day 41 and day 51. The results concluded that titanium nanoparticles produced by Bacillus subtilis remained non-cytotoxic because cell viability was >90%. Titanium nanoparticles produced by Cassia fistula revealed mild cytotoxicity on day 1, day 15 and day 31 because cell viability was 60−90%, while moderate cytotoxicity was found at day 41 and day 51, as cell viability was 30−60%. Titanium nanoparticles produced by hydrothermal heating depicted mild cytotoxicity on day 1 and day 15; moderate cytotoxicity on day 31; and severe cytotoxicity on day 41 and day 51 because cell viability was less than 30% (p < 0.001). The current study concluded that novel titanium nanoparticles prepared by Bacillus subtilis were the safest, more sustainable and most biocompatible for future restorative nano-dentistry purposes.
Topics: Mice; Animals; Humans; Titanium; Nanoparticles; Cell Line; Fibroblasts; Water
PubMed: 36296564
DOI: 10.3390/molecules27206972 -
Journal of Materials Science. Materials... May 2022This study investigated the corrosion susceptibility of pure titanium under uric acid exposure for 7 days based on surface analysis. The prepared pure titanium...
This study investigated the corrosion susceptibility of pure titanium under uric acid exposure for 7 days based on surface analysis. The prepared pure titanium specimens, exposed to different concentrations of uric acid, were examined for surface microstructure, surface element composition and surface wettability using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and static contact angle measurement, respectively. The corrosion behaviors of titanium specimens were measured by open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The titanium ion release from the prepared specimens, which were immersed in Hank's balanced salt solution (HBSS) containing different amount of uric acid, was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). More irregular pitting holes were observed on titanium surfaces exposed to a high concentration of uric acid, and XPS analyses revealed that the amount of titanium dioxide (TiO) decreased. Titanium surfaces pre-treated with high uric acid became more hydrophobic. Furthermore, the results of OCP and potentiodynamic polarization tests showed increased corrosion susceptibility of titanium samples, while EIS data indicated more active corrosion behavior of titanium materials. The high concentration of uric acid also induced titanium ion release. High concentration of uric acid negatively influenced the surface characteristics and corrosion properties of titanium materials, which destroyed the titanium oxide film barrier. High uric acid exposure increased corrosion susceptibility of pure titanium specimens and accelerated titanium ion release. Graphical abstract.
Topics: Corrosion; Materials Testing; Photoelectron Spectroscopy; Surface Properties; Titanium; Uric Acid
PubMed: 35575837
DOI: 10.1007/s10856-022-06667-2 -
Archivum Immunologiae Et Therapiae... Aug 2012This review focuses on the antibacterial activities of visible light-responsive titanium dioxide (TiO(2)) photocatalysts. These photocatalysts have a range of... (Review)
Review
This review focuses on the antibacterial activities of visible light-responsive titanium dioxide (TiO(2)) photocatalysts. These photocatalysts have a range of applications including disinfection, air and water cleaning, deodorization, and pollution and environmental control. Titanium dioxide is a chemically stable and inert material, and can continuously exert antimicrobial effects when illuminated. The energy source could be solar light; therefore, TiO(2) photocatalysts are also useful in remote areas where electricity is insufficient. However, because of its large band gap for excitation, only biohazardous ultraviolet (UV) light irradiation can excite TiO(2), which limits its application in the living environment. To extend its application, impurity doping, through metal coating and controlled calcination, has successfully modified the substrates of TiO(2) to expand its absorption wavelengths to the visible light region. Previous studies have investigated the antibacterial abilities of visible light-responsive photocatalysts using the model bacteria Escherichia coli and human pathogens. The modified TiO(2) photocatalysts significantly reduced the numbers of surviving bacterial cells in response to visible light illumination. They also significantly reduced the activity of bacterial endospores; reducing their toxicity while retaining their germinating abilities. It is suggested that the photocatalytic killing mechanism initially damages the surfaces weak points of the bacterial cells, before totally breakage of the cell membranes. The internal bacterial components then leak from the cells through the damaged sites. Finally, the photocatalytic reaction oxidizes the cell debris. In summary, visible light-responsive TiO(2) photocatalysts are more convenient than the traditional UV light-responsive TiO(2) photocatalysts because they do not require harmful UV light irradiation to function. These photocatalysts, thus, provide a promising and feasible approach for disinfection of pathogenic bacteria; facilitating the prevention of infectious diseases.
Topics: Anti-Bacterial Agents; Bacteria; Catalysis; Disinfectants; Disinfection; Humans; Light; Microbial Viability; Photochemical Processes; Photosensitizing Agents; Spores, Bacterial; Titanium
PubMed: 22678625
DOI: 10.1007/s00005-012-0178-x -
Cells Oct 2022Titanium-based implants are often utilized in oral implantology and craniofacial reconstructions. However, the biological inertness of machined titanium commonly results...
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.
Topics: Mice; Animals; Osseointegration; Titanium; Surface Properties; Nanotubes
PubMed: 36359812
DOI: 10.3390/cells11213417 -
Particle and Fibre Toxicology Jul 2019Titanium dioxide (TiO) nanoparticles are among the most manufactured nanomaterials in the industry, and are used in food products, toothpastes, cosmetics and paints....
BACKGROUND
Titanium dioxide (TiO) nanoparticles are among the most manufactured nanomaterials in the industry, and are used in food products, toothpastes, cosmetics and paints. Pregnant women as well as their conceptuses may be exposed to TiO nanoparticles; however, the potential effects of these nanoparticles during pregnancy are controversial, and their internal distribution has not been investigated. Therefore, in this study, we investigated the potential effects of oral exposure to TiO nanoparticles and their distribution during pregnancy. TiO nanoparticles were orally administered to pregnant Sprague-Dawley rats (12 females per group) from gestation days (GDs) 6 to 19 at dosage levels of 0, 100, 300 and 1000 mg/kg/day, and then cesarean sections were conducted on GD 20.
RESULTS
In the maternal and embryo-fetal examinations, there were no marked toxicities in terms of general clinical signs, body weight, food consumption, organ weights, macroscopic findings, cesarean section parameters and fetal morphological examinations. In the distribution analysis, titanium contents were increased in the maternal liver, maternal brain and placenta after exposure to high doses of TiO nanoparticles.
CONCLUSION
Oral exposure to TiO during pregnancy increased the titanium concentrations in the maternal liver, maternal brain and placenta, but these levels did not induce marked toxicities in maternal animals or affect embryo-fetal development. These results could be used to evaluate the human risk assessment of TiO nanoparticle oral exposure during pregnancy, and additional comprehensive toxicity studies are deemed necessary considering the possibility of complex exposure scenarios and the various sizes of TiO nanoparticles.
Topics: Administration, Oral; Animals; Brain; Dose-Response Relationship, Drug; Female; Liver; Maternal Exposure; Nanoparticles; Organ Specificity; Placenta; Pregnancy; Rats; Tissue Distribution; Titanium
PubMed: 31319864
DOI: 10.1186/s12989-019-0313-5 -
International Journal of Molecular... May 2022Titanium matrix composites (TMCs) with excellent mechanical properties, reinforced by graphene, is deemed the lightweight and high strength structural materials. In this...
Titanium matrix composites (TMCs) with excellent mechanical properties, reinforced by graphene, is deemed the lightweight and high strength structural materials. In this study, TC11 titanium alloy powder and graphene nanosheets (GNPs) were used as raw materials, and the composite powder with good uniformity and fluidity was obtained through non-interventional homogeneous mixing by a planetary mixer. The microstructure and mechanical properties of the GNPs-TC11 composites and TC11 alloy were compared. The results showed that the microstructure of TC11 and the composites was acicular martensite α' phase under the process parameters of 280 W laser power, 1200 mm/s scanning speed, and 0.1 mm hatch spacing. The GNPs in addition, in the composites, reduced the acicular martensite particle size and expanded the proportion of low-angle grain boundaries. The tensile strength and percentage elongation after the fracture of the TC11 titanium alloy were 1265 MPa and 4.3%, respectively. Because of addition of the GNPs, the strength and percentage elongation after the fracture of the composite increased to 1384 MPa and 8.1%, respectively, at a GNPs mass content of 0.2%. The enhancement of mechanical properties can be attributed to grain refinement, dislocation strengthening, Orowan strengthening, and load transfer strengthening.
Topics: Alloys; Graphite; Lasers; Powders; Surface Properties; Titanium
PubMed: 35682812
DOI: 10.3390/ijms23116134 -
International Journal of Molecular... Aug 2021Titanium has been used in osteosynthesis for decades and its compatibility and safety is unquestioned. Studies have shown that there is release and collection of...
BACKGROUND
Titanium has been used in osteosynthesis for decades and its compatibility and safety is unquestioned. Studies have shown that there is release and collection of titanium in the organ systems with little note of toxicity. The gold standard is considered to be titanium osteosynthesis plate produced by milling methods. The use of customized titanium plates produced with 3D printing, specifically direct metal laser sintering, have found increasing use in recent years. It is unknown how much titanium is released in these printed titanium implants, which is known to be potentially porous, depending on the heat settings of the printer. We hypothesize that the amount of titanium released in printed titanium implants may be potentially more or equal compared to the gold standard, which is the implant produced by milling.
METHODS
We studied the biosafety of this technology and its products by measuring serum and organ titanium levels after implantation of 3D-printed versus traditionally fabrication titanium plates and screws in a pilot study using the rabbit model. A total of nine rabbits were used, with three each in the control, milled and printed titanium group. The animals were euthanized after six months. Serum and organs of the reticuloendothelial system were harvested, digested and assayed for titanium levels.
RESULTS
Organ and serum titanium levels were significantly higher in rabbit subjects implanted with titanium implants (milled and printed) compared to the control group. However, there was no significant difference in organ and serum titanium levels of subjects implanted with milled and traditionally fabricated titanium implants.
CONCLUSIONS
The biosafety of use of 3D-printed titanium implants and traditionally fabricated titanium implants are comparable. With this in mind, 3D-printed custom implants can not only replace, but will very possibly surpass traditionally fabricated titanium implants in the mode and extent of use.
Topics: Animals; Biocompatible Materials; Bone Plates; Lasers; Male; Pilot Projects; Printing, Three-Dimensional; Rabbits; Titanium
PubMed: 34445182
DOI: 10.3390/ijms22168480 -
Brazilian Dental Journal 2023The present study evaluated the influence of carvacrol, terpinene-4-ol, and chlorhexidine on the physical-chemical properties of titanium surfaces, cell viability,...
The present study evaluated the influence of carvacrol, terpinene-4-ol, and chlorhexidine on the physical-chemical properties of titanium surfaces, cell viability, proliferation, adhesion, and spreading of fibroblasts and osteoblasts in vitro. Titanium surfaces (Ti) were treated with Carvacrol (Cvc), Terpinen-4-ol (T4ol), Chlorhexidine (CHX), DMSO, and ultrapure water (Control group). Physical-chemical modifications were evaluated by surface wettability, the surface free energy (SFE) calculated from the contact angle values using the Owens-Wendt-Rabel-Kaeble (OWRK) equation, scanning electron microscopy (SEM) and energy dispersive spectrometry probe (EDS) system. Cells were seeded onto Ti-treated surfaces and incubated for 24 h and 72 h, then evaluated by Alamar blue assay and fluorescence microscopy. Surfaces treated with Cvc and T4ol showed the presence of Na, O, and Cl. All surfaces showed hydrophilic characteristics and SFE values between 5.5 mN/m and 3.4 mN/m. On the other hand, EDS peaks demonstrated the presence of O and Cl after CHX treatment. A reduction of cell viability and adhesion was noted on titanium surfaces treated with CHX after 24 and 72h. In conclusion, the results indicate that the decontamination with Cvc and T4ol on Ti surfaces does not alter the surface proprieties and allows an adequate interaction with cells involved in the re-osseointegration process such as fibroblasts and osteoblasts.
Topics: Surface Properties; Titanium; Chlorhexidine; Wettability; Osteoblasts; Microscopy, Electron, Scanning; Cell Adhesion; Cell Proliferation
PubMed: 38133473
DOI: 10.1590/0103-6440202305582 -
Molecules (Basel, Switzerland) Dec 2022Recent studies on the removal of pollutants via adsorption include the use of carbon-based adsorbents, due to their high porosity and large surface area; however, such...
Recent studies on the removal of pollutants via adsorption include the use of carbon-based adsorbents, due to their high porosity and large surface area; however, such materials lack photoactive properties. This study evaluates the synergistic effect of integrated mesoporous carbon xerogel (derived from resorcinol formaldehyde) and titanium dioxide (TiO) for combined adsorption and photodegradation application. The complex formed between carbon xerogel and TiO phase was investigated through FTIR, proving the presence of a Ti-O-C chemical linkage. The physicochemical properties of the synthesised adsorbent-photocatalyst were probed using FESEM, BET analysis and UV-Vis analysis. The kinetics, equilibrium adsorption, effect of pH, and effect of adsorbent dosage were investigated. The expansion of the absorbance range to the visible range was verified, and the corresponding band gap evaluated. These properties enabled a visible light response when the system was exposed to visible light post adsorption. Hence, an assistive adsorption-photodegradation phenomenon was successfully executed. The adsorption performance exhibited 85% dye degradation which improved to 99% following photodegradation. Further experiments showed the reduction of microorganisms under visible light, where no microbial colonies were observed after treatment, indicating the potential application of these composite materials.
Topics: Environmental Pollutants; Photolysis; Titanium; Adsorption; Carbon; Catalysis
PubMed: 36500576
DOI: 10.3390/molecules27238483 -
International Journal of Molecular... Feb 2022Titanium dioxide is one of the best described photosensitive materials used in photocatalysis, solar cells, self-cleaning coatings, and sunscreens. The scientific and...
Titanium dioxide is one of the best described photosensitive materials used in photocatalysis, solar cells, self-cleaning coatings, and sunscreens. The scientific and industrial attention has been focused on the highly photoactive crystalline phase of titanium dioxide (TiO). It is commonly accepted that the smaller TiO particles, the higher photoactivity they present. Therefore, titanium dioxide nanoparticles are massively produced and widely used in everyday products. The amorphous phase of titanium dioxide has been treated with neglect, as the lack of its photocatalytic properties is assumed in advance. In this work, the complex experimental proof of the UV-protective properties of the nano-sized amorphous TiO phase is reported. Amorphous n-TiO is characterized by photocatalytic inactivity and, as a consequence, low cytotoxicity to fibroblast cells. When exposed to UV radiation, cells with amorphous TiO better survive under stress conditions. Thus, we postulate that amorphous n-TiO will be more beneficial and completely safe for cosmetic applications. Moreover, the results from in situ FTIR studies let us correlate the low toxicity of amorphous samples with low ability to form hydroperoxo surface species.
Topics: Cosmetics; Nanoparticles; Titanium; Ultraviolet Rays
PubMed: 35269599
DOI: 10.3390/ijms23052460