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Journal of Biomedical Materials... Apr 2023The aim of this study was to develop a novel biodegradable magnesium (Mg) alloy for bone implant applications. We used scandium (Sc; 2 wt %) and strontium (Sr;...
The aim of this study was to develop a novel biodegradable magnesium (Mg) alloy for bone implant applications. We used scandium (Sc; 2 wt %) and strontium (Sr; 2 wt %) as alloying elements due to their high biocompatibility, antibacterial efficacy, osteogenesis, and protective effects against corrosion. In the present work, we also examined the effect of a heat treatment process on the properties of the Mg-Sc-Sr alloy. Alloys were manufactured using a metal casting process followed by heat treatment. The microstructure, corrosion, mechanical properties, antibacterial activity, and osteogenic activity of the alloy were assessed in vitro. The results showed that the incorporation of Sc and Sr elements controlled the corrosion, reduced the hydrogen generation, and enhanced mechanical properties. Furthermore, alloying with Sc and Sr demonstrated a significantly enhanced antibacterial activity and decreased biofilm formation compared to control Mg. Also, culturing Mg-Sc-Sr alloy with human bone marrow-derived mesenchymal stromal cells showed a high degree of biocompatibility (>90% live cells) and a significant increase in osteoblastic differentiation in vitro shown by Alizarin red staining and alkaline phosphatase activity. Based on these results, the Mg-Sc-Sr alloy heat-treated at 400°C displayed optimal mechanical properties, corrosion rate, antibacterial efficacy, and osteoinductivity. These characteristics make the Mg-Sc-Sr alloy a promising candidate for biodegradable orthopedic implants in the fixation of bone fractures such as bone plate-screws or intramedullary nails.
Topics: Humans; Osteogenesis; Magnesium; Alloys; Corrosion; Absorbable Implants; Strontium; Anti-Bacterial Agents; Materials Testing
PubMed: 36494895
DOI: 10.1002/jbm.a.37476 -
PloS One 2019Metallic Zn alloys have recently gained interest as potential candidates for developing platforms of bioresorbable vascular stents (BVS). Previous studies revealed that...
Metallic Zn alloys have recently gained interest as potential candidates for developing platforms of bioresorbable vascular stents (BVS). Previous studies revealed that Mg alloys used for BVS can degrade too early, whereas PLLA materials may fail to provide effective scaffolding properties. Here we report on results of a new bioresorbable, metallic stent made from a Zn-Ag alloy studied in a porcine animal model of thrombosis and restenosis. While the tensile strength (MPa) of Zn-3Ag was higher than that of PLLA and resembled Mg's (WE43), fracture elongation (%) of Zn-3Ag was much greater (18-fold) than the PLLA's or Mg alloy's (WE43). Zn-3Ag exposed to HAoSMC culture medium for 30 days revealed degradation elements consisting of Zn, O, N, C, P, and Na at a 6 nm surface depth. Platelet adhesion rates and blood biocompatibility did not differ between Zn-3Ag, PLLA, Mg (WE43), and non-resorbable Nitinol (NiTi) stent materials. Balloon-expandable Zn-3Ag alloy BVS implanted into iliofemoral arteries of 15 juvenile domestic pigs were easily visible fluoroscopically at implantation, and their bioresorption was readily detectable via X-ray over time. Histologically, arteries with Zn-3Ag BVS were completely endothelialized, covered with neointima, and were patent at 1, 3, and 6 months follow-up with no signs of stent thrombosis. Zn-3Ag alloy appears to be a promising material platform for the fabrication of a new generation of bioresorbable vascular stents.
Topics: Absorbable Implants; Alloys; Animals; Drug-Eluting Stents; Polyesters; Swine; Thrombosis; Zinc
PubMed: 30601854
DOI: 10.1371/journal.pone.0209111 -
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 -
BioMed Research International 2023Biodegradable iron alloy implants have become one of the most ideal possible candidates because of their biocompatibility and comprehensive mechanical properties. Iron...
Biodegradable iron alloy implants have become one of the most ideal possible candidates because of their biocompatibility and comprehensive mechanical properties. Iron alloy's impact on chondrocytes is still unknown, though. This investigation looked at the biocompatibility and degradation of the Fe30Mn0.6N alloy as well as how it affected bone formation and chondrocyte autophagy. In vivo implantation of Fe30Mn0.6N and Ti6Al4V rods into rabbit femoral cartilage and femoral shaft was carried out to evaluate the degradation of the alloy and the cartilage and bone response at different intervals. After 8 weeks of implantation, the cross-sectional area of the Fe30Mn0.6N alloys lowered by 50.79 ± 9.59%. More Ca and P element deposition was found on the surface Fe30Mn0.6N rods by using energy dispersive spectroscopy (EDS) and scanning electron microscopy ( < 0.05). After 2, 4, and 8 weeks of implantation, no evident inflammatory infiltration was seen in peri-implant cartilage and bone tissue of Fe30Mn0.6N and Ti6Al4V alloys. Also, implantation of Fe30Mn0.6N alloy promoted autophagy in cartilage by detecting expression of LC3-II compared with Ti6Al4V after implantation ( < 0.05). Fe30Mn0.6N alloy also stimulated early osteogenesis at the peri-implant interface compared with Ti6Al4V after implantation ( < 0.05). In the in vitro test, we found that low concentrations of Fe30Mn0.6N extracts had no influence on cell viability. 15% and 30% extracts of Fe30Mn0.6N could upregulate autophagy compared to the control group by detecting beclin-1, LC3, Atg3, and P62 on the basis of WB and IHC ( < 0.05). Also, the PI3K-AKT-mTOR signaling pathway mediated in the upregulation of autophagy of chondrocytes resulting in exposure to extract of Fe30Mn0.6N alloy. It is concluded that Fe30Mn0.6N showed degradability and biocompatibility in vivo and upregulated autophagy activity in chondrocytes.
Topics: Animals; Rabbits; Osteogenesis; Phosphatidylinositol 3-Kinases; Femur; Alloys; Absorbable Implants; Cartilage
PubMed: 36714031
DOI: 10.1155/2023/3626776 -
Journal of Biomedical Materials... Feb 2023Magnesium (Mg) alloy-based porous bio-nanocomposite bone scaffolds were developed by powder metallurgy route. Selective alloying elements such as calcium (Ca), zinc (Zn)...
Magnesium (Mg) alloy-based porous bio-nanocomposite bone scaffolds were developed by powder metallurgy route. Selective alloying elements such as calcium (Ca), zinc (Zn) and strontium (Sr) were incorporated to tune the mechanical integrity while, bioactive fluorcanasite nano-particulates were introduced within the alloy system to enhance the bone tissue regeneration. Green compacts containing carbamide were fabricated and sintered using two-stage heat treatment process to achieve the targeted porosities. The microstructure of these fabricated magnesium alloy-based bio-nanocomposites was examined by Field emission scanning electron microscope (FE-SEM) and x-ray micro computed tomography (x-ray μCT), which revealed gradient porosities and distribution of alloying elements. X-ray diffraction (XRD) studies confirmed the presence of major crystalline phases in the fabricated samples and the evolution of the various combinations of intermetallic phases of Ca, Mg, Zn and Sr which were anticipated to enhance the mechanical properties. Further, XRD studies revealed the presence of apatite phase for the immersed samples, a conducive environment for bone regeneration. The fabricated samples were evaluated for their mechanical performance against uniaxial compression load. The tunability of compressive strengths and modulus values could be established with variation in porosities of fabricated samples. The retained compressive strength and Young's modulus of the samples following immersion in phosphate buffered saline (PBS) solution was found to be in line with that of natural human cancellous bone, thereby establishing the potential of the fabricated magnesium-alloy-based nanocomposite as a promising scaffold candidate for bone tissue engineering.
Topics: Humans; Alloys; Magnesium; X-Ray Microtomography; Porosity; Nanocomposites; Strontium; Tissue Scaffolds
PubMed: 36208413
DOI: 10.1002/jbm.b.35166 -
Molecules (Basel, Switzerland) Feb 2019Here we report a TiV-10 wt.% C alloy with a unique lattice and microstructure for hydrogen storage development. Different from a traditionally synthesized TiV alloy...
Here we report a TiV-10 wt.% C alloy with a unique lattice and microstructure for hydrogen storage development. Different from a traditionally synthesized TiV alloy prepared by a melting method and having a body-centered cubic (BCC) structure, this TiV-C alloy synthesized by a mechanical alloying method is with a face-centered cubic (FCC) structure (space group: No. 225). The crystalline size is 60 nm. This alloy may directly absorb hydrogen near room temperature without any activation process. Mechanisms of the good kinetics from lattice and microstructure aspects were discussed. Findings reported here may indicate a new possibility in the development of future hydrogen storage materials.
Topics: Alloys; Carbon; Hydrogen; Kinetics; Materials Testing; Surface Properties; Titanium; Vanadium
PubMed: 30717403
DOI: 10.3390/molecules24030552 -
Materials Science & Engineering. C,... Mar 2020To instill pure Ti with an antibacterial effect, Cu was added by metallurgical alloying to produce Ti-5 wt% Cu alloy (Ti-5Cu alloy). The precipitation of the likes of...
To instill pure Ti with an antibacterial effect, Cu was added by metallurgical alloying to produce Ti-5 wt% Cu alloy (Ti-5Cu alloy). The precipitation of the likes of TiCu in a Ti-Cu alloy is one of the factors that influences its antibacterial property. However, in the present study, Ti-5Cu alloy precipitates with different microstructures were obtained by applying heat treatment at different temperatures and for different durations. After the heat treatment, metallographic, microstructure, and element analyses were performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDS). The antibacterial property of the Ti-5Cu alloy was assessed by the plated-count method using Escherichia coli (E. coli). The microstructure analysis revealed that the solution-treated alloy had no precipitation, while the aged alloy contained precipitations of intermetallic TiCu compound. The aged alloy exhibited better antibacterial performance as the duration of the aging treatment increased. The optimal heat treatment for Ti-5Cu was found to be aging at 700 °C for 4 h, at which point the nucleation formation of the TiCu particles would assume an acicular morphology. These acicular precipitates exhibit a high Cu content which, in turn, influences the antibacterial performance.
Topics: Alloys; Anti-Bacterial Agents; Escherichia coli
PubMed: 31923945
DOI: 10.1016/j.msec.2019.110433 -
Biotechnology and Bioengineering Apr 2022Cobalt-chromium-molybdenum (CCM) alloys possess high corrosion-resistant properties as well as good mechanical properties. Hence, the alloys are employed in medical...
Cobalt-chromium-molybdenum (CCM) alloys possess high corrosion-resistant properties as well as good mechanical properties. Hence, the alloys are employed in medical implants such as artificial knee and hip joints, coronary stents, and removable partial dentures. To improve the biocompatibility of CCM alloys, we reported that CCM-binding peptide (CBP) linked to cell-adhesive motif Arg-Gly-Asp (RGD) improved the attachment of endothelial cells on CCM alloys. However, the stability of CBP adsorption on the alloy and its effect on osteoblast compatibility are still unclear. In this study, we evaluated the stabilization of the adsorption layer of CBP-RGD on CCM alloy surface and investigated the effect of CBP-RGD peptide on the proliferation and differentiation of the osteoblasts. CBP-RGD layer exhibited higher stabilization than the RGD adsorption layer for 7 days. In addition, the proliferation of osteoblast on CBP-RGD adsorbed alloy higher than that on RGD adsorbed alloy. Moreover, the calcification of cells cultured on the CBP-RGD adsorbed alloy was significantly higher than that of the cells on RGD adsorbed alloy. These findings indicate that the CBP binding was stable during the culture of osteoblasts on the CCM alloy.
Topics: Alloys; Cell Proliferation; Endothelial Cells; Materials Testing; Osteoblasts; Peptides; Surface Properties; Vitallium
PubMed: 35067921
DOI: 10.1002/bit.28041 -
Small (Weinheim An Der Bergstrasse,... Jan 2012This review describes the use of chemically modified pure and alloyed metal nanoparticles for chemiresistive sensing applications. Chemically modified metal... (Review)
Review
This review describes the use of chemically modified pure and alloyed metal nanoparticles for chemiresistive sensing applications. Chemically modified metal nanoparticles consist of a pure or alloyed metallic core with some type of chemical coating. Researchers have studied the electronic properties of 1D, 2D, and 3D assemblies of chemically modified metal nanoparticles, and even single individual nanoparticles. The interaction with the analyte alters the conductivity of the sensitive material, providing a signal to measure the analyte concentration. This review focuses on chemiresistive sensing of a wide variety of gas- and liquid-phase analytes with metal nanoparticles coated with organothiols, ions, polymers, surfactants, and biomolecules. Different strategies used to incorporate chemically modified nanoparticles into chemiresistive sensing devices are reviewed, focusing on the different types of metal and alloy compositions, coatings, methods of assembly, and analytes (vapors, gases, liquids, biological materials), along with other important factors.
Topics: Alloys; Biosensing Techniques; DNA; Dendrimers; Electric Conductivity; Gases; Metal Nanoparticles; Metals; Microscopy, Electron, Scanning; Organic Chemicals; Polymers; Static Electricity; Surface-Active Agents
PubMed: 22052721
DOI: 10.1002/smll.201002232 -
Optics Letters Apr 2022Due to their tunable physical and chemical properties, alloys are of fundamental importance in material science. The determination of stoichiometry is crucial for alloy...
Due to their tunable physical and chemical properties, alloys are of fundamental importance in material science. The determination of stoichiometry is crucial for alloy engineering. Classical characterization tools such as energy-dispersive x-ray spectroscopy (EDX) are time consuming and cannot be performed in an ambient atmosphere. In this context, we introduce a new methodology to determine the stoichiometry of alloys from ellipsometric measurements. This approach, based on the analysis of ellipsometric spectra by an artificial neural network (ANN), is applied to electrum alloys. We demonstrate that the accuracy of this approach is of the same order of magnitude as that of EDX. In addition, the ANN analysis is sufficiently robust that it can be used to characterize rough alloys. Finally, we demonstrate that the exploitation of ellipsometric maps with the ANN is a powerful tool to determine composition gradients in alloys.
Topics: Alloys; Neural Networks, Computer; Spectrometry, X-Ray Emission
PubMed: 35427351
DOI: 10.1364/OL.457147