-
Journal of the Mechanical Behavior of... Jun 2023Titanium alloys have gained popularity as a bioimplant material due to their biocompatibility, low modulus of elasticity, and increased strength. However, other issues,...
Titanium alloys have gained popularity as a bioimplant material due to their biocompatibility, low modulus of elasticity, and increased strength. However, other issues, such as corrosion resistance, and infections can reduce the implant's lifespan. This paper aims to fabricate a new Ti-30Nb-3Ag at% alloy with enhanced in vitro corrosion and antibacterial properties by mechanical alloying (MA) followed by powder consolidation. XRD, SEM/EDX, and Vickers microhardness analyses were used to examine the phases compositions, microstructure, and microhardness, respectively. The in vitro corrosion performance of Ti-30Nb-3Ag alloy was inspected in a simulated body medium and artificial saliva. The alloy's antibacterial properties were evaluated in the gram-positive and negative bacterial medium. The results showed that after MA for 60 h, nanocrystalline β-Ti (BCC) and α-Ti (HCP) solid solutions were formed with crystallite sizes of 7.44 and 3.47 nm, respectively. The sintered sample exhibited densifications of 97%, with a microstructure composed of β-Ti, α-Ti, and a minor quantity of ultrafine TiAg phase. The microhardness result showed that Ti-30Nb-3Ag alloy possesses HV 491.5. Ti-30Nb-3Ag alloy has a potent antibacterial capability of 85.75% and 88.81% relative to Ti-6Al-4V alloy and CP-Ti, respectively. In vitro corrosion results revealed that the Ti-30Nb-3Ag alloy exhibited the widespread passive area in the investigated anodic regions and presented the highest impedance values in comparison with the commercial alloys, confirming its improved corrosion resistance performance in both studied mediums. Ti-30Nb-3Ag alloy possibly be a competitive bioimplant material for orthopedic and dental uses owing to its enhanced biocorrosion and antibacterial properties compared to commercial Ti-6Al-4V alloy and CP-Ti.
Topics: Titanium; Corrosion; Alloys; Anti-Bacterial Agents; Surface Properties; Materials Testing
PubMed: 37068434
DOI: 10.1016/j.jmbbm.2023.105851 -
Journal of Prosthodontics : Official... Jul 2023This study aimed to explore the antimicrobial properties of graphene coated Ti-6Al-4V to oral pathogens.
PURPOSE
This study aimed to explore the antimicrobial properties of graphene coated Ti-6Al-4V to oral pathogens.
MATERIALS AND METHODS
Graphene directly synthesized on Ti-6Al-4V alloy was characterized by scanning electron microscopy (SEM) and Raman spectroscopy. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, live/dead fluorescent staining and SEM were used to analyze the antimicrobial properties of graphene coated Ti-6Al-4V alloy to Porphyromonas gingivalis (P. gingivalis), Fusobacterium nucleatum (F. nucleatum), and Candida albicans (C. albicans). Reactive oxygen species (ROS) generation was monitored to reveal the antimicrobial mechanism.
RESULTS
Graphene coated Ti-6Al-4V alloy caused a significant reduction in the presence of both bacterial and fungal pathogens as compared to uncoated Ti-6Al-4V alloy. P. gingivalis, F. nucleatum, and C. albicans on graphene coated Ti-6Al-4V alloy were less active than on uncoated Ti-6Al-4V alloy, and tended to become shrunk and deformed. Meanwhile, graphene coated Ti-6Al-4V alloy induced more generation of ROS in the pathogens than uncoated Ti-6Al-4V alloy.
CONCLUSIONS
Graphene coated Ti-6Al-4V alloy exhibited antimicrobial properties against oral pathogens, the induction of oxidative stress might be involved in its antimicrobial mechanisms.
Topics: Materials Testing; Antifungal Agents; Graphite; Reactive Oxygen Species; Surface Properties; Alloys; Titanium; Anti-Bacterial Agents
PubMed: 35988055
DOI: 10.1111/jopr.13595 -
Scientific Reports Feb 2023The performance of current biomedical titanium alloys is limited by inflammatory and severe inflammatory conditions after implantation. In this study, a novel...
The performance of current biomedical titanium alloys is limited by inflammatory and severe inflammatory conditions after implantation. In this study, a novel Ti-Nb-Zr-Si (TNZS) alloy was developed and compared with commercially pure titanium, and Ti-6Al-4V alloy. Electrochemical parameters of specimens were monitored during 1 h and 12 h immersion in phosphate buffered saline (PBS) as a normal, PBS/hydrogen peroxide (HO) as an inflammatory, and PBS/HO/albumin/lactate as a severe inflammatory media. The results showed an effect of the HO in inflammatory condition and the synergistic behavior of HO, albumin, and lactate in severe inflammatory condition towards decreasing the corrosion resistance of titanium biomaterials. Electrochemical tests revealed a superior corrosion resistance of the TNZS in all conditions due to the presence of silicide phases. The developed TNZS was tested for subsequent cell culture investigation to understand its biocompatibility nature. It exhibited favorable cell-materials interactions in vitro compared with Ti-6Al-4V. The results suggest that TNZS alloy might be a competitive biomaterial for orthopedic applications.
Topics: Titanium; Niobium; Hydrogen Peroxide; Biocompatible Materials; Alloys; Albumins; Corrosion; Lactic Acid; Materials Testing; Surface Properties
PubMed: 36759646
DOI: 10.1038/s41598-023-29553-5 -
Nature Materials Oct 2022Rare earth (RE) addition to steels to produce RE steels has been widely applied when aiming to improve steel properties. However, RE steels have exhibited extremely...
Rare earth (RE) addition to steels to produce RE steels has been widely applied when aiming to improve steel properties. However, RE steels have exhibited extremely variable mechanical performances, which has become a bottleneck in the past few decades for their production, utilization and related study. Here in this work, we discovered that the property variation of RE steels stems from the presence of oxygen-based inclusions. We proposed a dual low-oxygen technology, and keeping low levels of oxygen content in steel melts and particularly in the raw RE materials, which have long been ignored, to achieve impressively stable and favourable RE effects. The fatigue life is greatly improved by only parts-per-million-level RE addition, with a 40-fold improvement for the tension-compression fatigue life and a 40% enhancement of the rolling contact fatigue life. We find that RE appears to act by lowering the carbon diffusion rate and by retarding ferrite nucleation at the austenite grain boundaries. Our study reveals that only under very low-oxygen conditions can RE perform a vital role in purifying, modifying and micro-alloying steels, to improve the performance of RE steels.
Topics: Alloys; Carbon; Oxygen; Steel
PubMed: 36075967
DOI: 10.1038/s41563-022-01352-9 -
Biomedical Physics & Engineering Express May 2022With changing lifestyles, the demand for bone implantation has been increasing day by day. The deficiency of nutritious elements within the human body results in certain... (Review)
Review
With changing lifestyles, the demand for bone implantation has been increasing day by day. The deficiency of nutritious elements within the human body results in certain diseases like osteoporosis, rickets, and other skeletal disorders; lack of physical activities; and the increasing number of accidents are the primary reasons for bone damage/fracture. Metallic implants made up of chrome steel, cobalt-based alloys, and titanium-based alloys are being majorly used worldwide owing to their high strength and high corrosion resistance which makes them permanent orthopedic bioimplant materials, however, they display a stress-shielding effect and it also requires an implant removal surgery. Thus, these problems can be addressed through the employment of biodegradable materials. Among the available biodegradable metallic materials, Mg alloys have been identified as a prospective orthopedic implant material. These alloys are biodegradable as well as biocompatible, however, they experience a relatively higher rate of degradation limiting their usability as implant material. This study attempts to comprehensively assess the effects of various alloying elements such as Ca, Zn, Sn, Mn, Sr and Rare earth elements (REEs) on the mechanical and degradation behavior (bothand) of Mg alloys. Since the microstructure, mechanical properties and degradation response of the Mg alloys are dependent on the processing route, hence detailed processing- property database of different Mg alloys is provided in this paper.
Topics: Alloys; Biocompatible Materials; Corrosion; Humans; Magnesium; Prospective Studies
PubMed: 35523119
DOI: 10.1088/2057-1976/ac6d81 -
Small (Weinheim An Der Bergstrasse,... Sep 2021The past decade has witnessed a rapidly growing interest toward sodium ion battery (SIB) for large-scale energy storage in view of the abundance and easy accessibility... (Review)
Review
The past decade has witnessed a rapidly growing interest toward sodium ion battery (SIB) for large-scale energy storage in view of the abundance and easy accessibility of sodium resources. Key to addressing the remaining challenges and setbacks and to translate lab science into commercializable products is the development of high-performance anode materials. Anode materials featuring combined conversion and alloying mechanisms are one of the most attractive candidates, due to their high theoretical capacities and relatively low working voltages. The current understanding of sodium-storage mechanisms in conversion-alloying anode materials is presented here. The challenges faced by these materials in SIBs, and the corresponding improvement strategies, are comprehensively discussed in correlation with the resulting electrochemical behavior. Finally, with the guidance and perspectives, a roadmap toward the development of advanced conversion-alloying materials for commercializable SIBs is created.
Topics: Alloys; Electrodes; Sodium
PubMed: 34331406
DOI: 10.1002/smll.202101137 -
Journal of Nanoscience and... Jul 2021In the context of biology and medicine, nanotechnology encompasses the materials, devices, and systems whose structure and function are relevant for small length scales,...
In the context of biology and medicine, nanotechnology encompasses the materials, devices, and systems whose structure and function are relevant for small length scales, from nanometers through microns. The purpose of this study was to compare the microstructures and resultant biocompatibility of three commercially available soft milled cobalt-chromium (Co-Cr) alloys (Ceramill Sintron, CS; Sintermetall, SML; and Soft Metal, SM). Disc-shaped specimens were prepared by milling the soft blanks and subsequent post-sintering. The crystal and microstructures of the three different alloys were studied using optical microscopy, X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy, and electron backscatter diffraction. The amounts of Co, Cr, and molybdenum (Mo) ions released from the alloys were evaluated using inductively coupled plasma-mass spectroscopy. The effect of ion release on the viability of L929 mouse fibroblasts was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The SML alloy showed a finer grain size (approx. 5 and a larger pore size (approx. 5 than the CS and SM alloys, and its XRD pattern exhibited a slightly higher ε phase peak intensity than that of the phase. In the CS and SML alloys, the average crystallite sizes of the nano-sized CrC carbide were 21.6 and 19.3 nm, respectively. The SML alloy showed higher concentrations of Cr and Mo in the grain boundaries than the other two alloys. The SML alloy showed significantly higher Co and Mo ion releases (p < 0.001) and significantly lower cell viability (p < 0.05) than the CS and SM alloys. The combined results of this study suggest that the three soft milled Co-Cr alloys had different crystal and microstructures and, as a result, different levels of biocompatibility.
Topics: Alloys; Animals; Chromium; Chromium Alloys; Cobalt; Dental Alloys; Materials Testing; Mice; Molybdenum; Spectrometry, X-Ray Emission
PubMed: 33715723
DOI: 10.1166/jnn.2021.19170 -
Acta Biomaterialia Oct 2022Zinc (Zn) alloys are a promising biodegradable material for vascular stent applications. This study aimed to fabricate biodegradable Zn-2.0Cu-0.5Mn alloy micro-tubes and...
Zinc (Zn) alloys are a promising biodegradable material for vascular stent applications. This study aimed to fabricate biodegradable Zn-2.0Cu-0.5Mn alloy micro-tubes and vascular stents with high dimensional accuracy and suitable mechanical properties, and to investigate their microstructure, texture, mechanical properties and corrosion behavior. The micro-tubes and vascular stents were successfully fabricated by a combined process of extrusion, drawing, laser cutting and electrochemical polishing. The microstructures of as-extruded and as-drawn micro-tubes consisted of Zn matrix with near-equiaxed grains (average grain size: ∼2 µm) and second phases of ε (CuZn) and MnZn with different sizes. The texture evolved from basal planes approximately paralleling to deformation direction for as-extruded micro-tube to approximately perpendicular to deformation direction for as-drawn micro-tube, because predominant deformation mechanisms changed from basal dislocation slip during tube extrusion to prismatic dislocation, pyramidal
dislocations, and {101¯2} twins during tube drawing. As-drawn micro-tube exhibited suitable mechanical properties with an ultimate tensile strength of about 298 MPa and elongation of about 26% as a stent material. Moreover, the processed stent with a thickness of about 125 µm possessed sufficient radial strength of about 150 kPa and good balloon expandability. In addition, as-drawn tube exhibited an in vitro corrosion rate of about 158 µm/year with a basically uniform corrosion morphology. These results indicated that biodegradable Zn-2.0Cu-0.5Mn alloy is a promising vascular stent material candidate, and the procedure for processing the micro-tube and stent is practical and effective. STATEMENT OF SIGNIFICANCE: Fabrication of micro-tubes followed by laser cutting and polishing is a common way to prepare metallic vascular stents. However, it is quite challenging to fabricate Zn-based stents using this standard method, and there is a lack of studies reporting processing details in the past. Biodegradable Zn-2.0Cu-0.5Mn alloy micro-tubes and vascular stents with high dimensional accuracy and suitable mechanical properties were successfully fabricated by a combined process in this study. As-drawn micro-tube exhibited an ultimate tensile strength of about 298 MPa and elongation of about 26%. The stent possessed sufficient radial strength of about 150 kPa and good balloon expandability. We demonstrated a practical method to fabricate biodegradable Zn-based micro-tubes and stents with high dimensional accuracy and mechanical properties. Topics: Absorbable Implants; Alloys; Biocompatible Materials; Corrosion; Materials Testing; Stents; Zinc
PubMed: 35917908
DOI: 10.1016/j.actbio.2022.07.049 -
Journal of Biomedical Materials... Aug 2019Magnesium (Mg) has emerged as an ideal alternative to the permanent implant materials owing to its enhanced properties such as biodegradation, better mechanical... (Review)
Review
Magnesium (Mg) has emerged as an ideal alternative to the permanent implant materials owing to its enhanced properties such as biodegradation, better mechanical strengths than polymeric biodegradable materials and biocompatibility. It has been under investigation as an implant material both in cardiovascular and orthopedic applications. The use of Mg as an implant material reduces the risk of long-term incompatible interaction of implant with tissues and eliminates the second surgical procedure to remove the implant, thus minimizes the complications. The hurdle in the extensive use of Mg implants is its fast degradation rate, which consequently reduces the mechanical strength to support the implant site. Alloy development, surface treatment, and design modification of implants are the routes that can lead to the improved corrosion resistance of Mg implants and extensive research is going on in all three directions. In this review, the recent trends in the alloying and surface treatment of Mg have been discussed in detail. Additionally, the recent progress in the use of computational models to analyze Mg bioimplants has been given special consideration. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1970-1996, 2019.
Topics: Absorbable Implants; Alloys; Animals; Humans; Magnesium; Materials Testing
PubMed: 30536973
DOI: 10.1002/jbm.b.34290 -
Bio-medical Materials and Engineering 2022Magnesium (Mg) alloy have biodegradation and mechanical properties that are similar to those of human bone, making it a promising candidate material for inclusion in...
BACKGROUND
Magnesium (Mg) alloy have biodegradation and mechanical properties that are similar to those of human bone, making it a promising candidate material for inclusion in implantable medical devices.
OBJECTIVE
The osteointegration effect of Mg alloy scaffolds with different corrosion rates were studied and evaluated in large bone defect models.
METHOD
Mg-Sr and Mg-Ca alloy scaffolds with a 20-μm Micro-arc oxidation (MAO) coating were used to repair critical bone defects for subsequent assessment of each alloy's degradation and osteointegration by X-ray, Micro-CT, fluorescence and histological examination.
RESULTS
At 12 weeks post-implantation, each defect was found to be effectively reconstructed by either of the Mg alloys based on X-ray and Micro-CT images. The corrosion rate (CR) of each Mg alloy - as calculated based on micro-computed tomography information - demonstrated that the MAO coating could provide effective protection for only 4 weeks post-surgery. From weeks 8 to 12, the CR of the Mg-Ca alloy scaffold increased from 1.34 ± 0.23 mm/y to 1.57 ± 0.16 mm/y. In contrast, the CR of the Mg-Sr alloy scaffold decreased from 0.58 ± 0.14 mm/y to 0.54 ± 0.16 mm/y. However, fluorescence and histological examination revealed more mature, closely and regularly arranged newborn osteocytes at the Mg-Ca scaffold-fracture interface e from weeks 8 to 12 after surgery.
CONCLUSION
The Mg-Sr scaffold was more corrosion resistant and the Mg-Ca scaffold yielded a better overall repair, which indicates that the CR of magnesium alloys matches the rate of new bone formation and is the key to repair bone defects as a bone substitute.
Topics: Alloys; Coated Materials, Biocompatible; Corrosion; Humans; Magnesium; Osteocytes; Osteogenesis; X-Ray Microtomography
PubMed: 34744060
DOI: 10.3233/BME-211300