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Journal of Biomedical Materials... Jan 2022Biosafety of AZ31B magnesium (Mg) alloy and the effect of its degradation products on tissues, organs, and whole systems are highly needed to be evaluated before...
Biosafety of AZ31B magnesium (Mg) alloy and the effect of its degradation products on tissues, organs, and whole systems are highly needed to be evaluated before clinical application. This study serves a wide variety of safety evaluations of biodegradable AZ31B alloy on nerve cells. As a result of this in vitro study, the maximum aluminum (Al) ion and Mg ion concentrations in the medium were estimated to be 22 μmol/L and 2.75 mmol/L, respectively, during degradation. In addition, the corresponding cell mortality was observed to be 36% and lower than 5% according to the resistance curves of the cell to Mg and Al ions. Furthermore, the maximum Al ion and Mg ion concentrations in serum and cerebrospinal fluid were detected to be 26.1 μmol/L and 1.2 mmol/L, respectively, for 5 months implantation. Combining the result of in vivo dialysis with the result of ion tolerance assay experiments, the actual death rate of nerve cells is estimated between 4 and 10% in vivo, which is lower than the result of in vitro cytotoxicity evaluation. Moreover, no psychomotor disability during clinical studies is observed. Consequently, stent made of AZ31B alloy with surface treatment is feasible for carotid artery stenosis, and it is safe in terms of cell viability on the nervous system.
Topics: Alloys; Carotid Arteries; Containment of Biohazards; Magnesium; Materials Testing; Stents
PubMed: 34236133
DOI: 10.1002/jbm.b.34907 -
Acta Biomaterialia Oct 2019Absorbable metals have the potential to serve as the next generation of temporary medical implant devices by safely dissolving in the human body upon vascular tissue... (Review)
Review
Absorbable metals have the potential to serve as the next generation of temporary medical implant devices by safely dissolving in the human body upon vascular tissue healing and bone regeneration. Their implementation in the market could greatly reduce the need of costly and risky additional surgeries for either implant replacement or removal, often required in current permanent implants. Despite the extensive research done over the last two decades on magnesium (Mg) and iron (Fe) based alloys, they have not generally shown a satisfactory combination of mechanical properties, biocompatibility and controlled degradation rate in the physiological environment. Consequently, zinc (Zn) based alloys were introduced in the last few years as alternative materials to overcome the limitations of Fe and Mg-based alloys. The blend of different alloying elements and processing conditions have led to a wide variety of Zn-based alloys having tunable mechanical properties and corrosion rates. This review provides the most recent progress in the development of absorbable Zn-based alloys for biomedical implant applications, primarily for cardiovascular and orthopedic devices. Their biocompatibility, processability and metallurgical aspects, as well as their mechanical behavior and corrosion properties are presented and discussed, including their opportunities, limitations and future research directions. STATEMENT OF SIGNIFICANCE: Temporary orthopedic bioimplants have become increasingly popular as they offer an alternative to prevent complications, like infections or secondary surgeries, often related to the implantation of permanent devices. Iron and magnesium alloys were extensively studied as candidates for absorbable medical applications, but they generally failed to provide a desirable mechanical performance and corrosion characteristics in the physiological environment. Zinc was introduced in the last decade as a potential implant material after showing outstanding biocompatibility and biodegradability. This review summarizes the research advances to date and provides a thorough discussion of the future challenges of absorbable zinc alloys to satisfy the demanding clinical benchmarks for absorbable medical applications. Their biocompatibility, mechanical, and corrosion aspects, both in vitro and in vivo, are comprehensively reviewed and assessed accordingly.
Topics: Absorbable Implants; Alloys; Biocompatible Materials; Corrosion; Humans; Iron; Magnesium; Zinc
PubMed: 31351253
DOI: 10.1016/j.actbio.2019.07.034 -
Journal of Prosthodontic Research Jan 2020In recent years, the application of restorations and fixed dental prostheses to molars by computer-aided design-computer-aided manufacturing (CAD/CAM) with composite... (Review)
Review
PURPOSE
In recent years, the application of restorations and fixed dental prostheses to molars by computer-aided design-computer-aided manufacturing (CAD/CAM) with composite resin has been increasing. Titanium and titanium alloy having a high tissue affinity and good biocompatibility are suitable for cases where CAD/CAM fabrications are inadequate, such as allergic reaction to metal. Many studies have reported methods of production with titanium and titanium alloys. The purpose of this review is to survey the clinical application of titanium and titanium alloy restorations and fixed dental prostheses with various fabrication systems.
STUDY SELECTION
A literature search in PubMed was performed for various fabrication systems of titanium and titanium alloy from 2010 through 2019. The search keywords were "titanium", "titanium alloy", "CAD/CAM", "cast", "fabrication system", "marginal gap", "internal gap", and "clinical performance". Only relevant studies are summarized and discussed in this review.
RESULTS
With any fabrication system, titanium and titanium alloy restorations and fixed dental prostheses fabricated with various systems were within the clinically acceptable ranges of marginal gap and internal fit. Additionally, these restorations were considered to have less effect on the periodontal issues. Although metal-ceramic restoration has clinical performance problems, such as ceramic fracture, fabrications with only titanium and titanium alloy were reported to have good clinical performance.
CONCLUSIONS
Regardless of the fabrication system, titanium and titanium alloy restorations and fixed dental prostheses can be applied clinically. Titanium and titanium alloys are thought to be a promising alternative to the dental metals currently used.
Topics: Alloys; Computer-Aided Design; Dental Marginal Adaptation; Dental Prosthesis Design; Metal Ceramic Alloys; Titanium
PubMed: 31711856
DOI: 10.1016/j.jpor.2019.07.008 -
International Journal of Molecular... Sep 2021Many current-generation biomedical implants are fabricated from the Ti-6Al-4V alloy because it has many attractive properties, such as low density and biocompatibility....
Many current-generation biomedical implants are fabricated from the Ti-6Al-4V alloy because it has many attractive properties, such as low density and biocompatibility. However, the elastic modulus of this alloy is much larger than that of the surrounding bone, leading to bone resorption and, eventually, implant failure. In the present study, we synthesized and performed a detailed analysis of a novel low elastic modulus Ti-based alloy (Ti-28Nb-5Zr-2Ta-2Sn (TNZTS alloy)) using a variety of methods, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and tensile test. Additionally, the in vitro biocompatibility of the TNZTS alloy was evaluated using SCP-1, SaOs-2, and THP-1 cell lines and primary human osteoblasts. Compared to Ti-6Al-4V, the elastic modulus of TNZTS alloy was significantly lower, while measures of its in vitro biocompatibility are comparable. O plasma treatment of the surface of the alloy significantly increased its hydrophilicity and, hence, its in vitro biocompatibility. TNZTS alloy specimens did not induce the release of cytokines by macrophages, indicating that such scaffolds would not trigger inflammatory responses. The present results suggest that the TNZTS alloy may have potential as an alternative to Ti-6Al-4V.
Topics: Alloys; Biocompatible Materials; Elastic Modulus; Humans; Hydrophobic and Hydrophilic Interactions; Materials Testing; Niobium; Osteoblasts; Prostheses and Implants; Surface Properties; THP-1 Cells; Tantalum; Tensile Strength; Tin; Titanium; Zirconium
PubMed: 34638960
DOI: 10.3390/ijms221910611 -
Journal of Neurosurgery Jul 2023Bioresorbable flow diverters (BRFDs) could significantly improve the performance of next-generation flow diverter technology. In the current work, magnesium and iron...
OBJECTIVE
Bioresorbable flow diverters (BRFDs) could significantly improve the performance of next-generation flow diverter technology. In the current work, magnesium and iron alloy BRFDs were prototyped and compared in terms of porosity/pore density, radial strength, flow diversion functionality, and resorption kinetics to offer insights into selecting the best available bioresorbable metal candidate for the BRFD application.
METHODS
BRFDs were constructed with braided wires made from alloys of magnesium (MgBRFD) or iron (FeBRFD). Pore density and crush resistance force were measured using established methods. BRFDs were deployed in silicone aneurysm models attached to flow loops to investigate flow diversion functionality and resorption kinetics in a simulated physiological environment.
RESULTS
The FeBRFD exhibited higher pore density (9.9 vs 4.3 pores/mm2) and crush resistance force (0.69 ± 0.05 vs 0.53 ± 0.05 N/cm, p = 0.0765, n = 3 per group) than the MgBRFD, although both crush resistances were within the range previously reported for FDA-approved flow diverters. The FeBRFD demonstrated greater flow diversion functionality than the MgBRFD, with significantly higher values of established flow diversion metrics (mean transit time 159.6 ± 11.9 vs 110.9 ± 1.6, p = 0.015; inverse washout slope 192.5 ± 9.0 vs 116.5 ± 1.5, p = 0.001; n = 3 per group; both metrics expressed as a percentage of the control condition). Last, the FeBRFD was able to maintain its braided structure for > 12 weeks, whereas the MgBRFD was almost completely resorbed after 5 weeks.
CONCLUSIONS
The results of this study demonstrated the ability to manufacture BRFDs with magnesium and iron alloys. The data suggest that the iron alloy is the superior material candidate for the BRFD application due to its higher mechanical strength and lower resorption rate relative to the magnesium alloy.
Topics: Humans; Intracranial Aneurysm; Magnesium; Iron; Absorbable Implants; Alloys
PubMed: 36681964
DOI: 10.3171/2022.11.JNS222213 -
Acta Biomaterialia Oct 2019To date, more than fifty articles have been published on the feasibility studies of zinc and its alloys as biodegradable metals. These preliminary in vitro and in vivo... (Review)
Review
To date, more than fifty articles have been published on the feasibility studies of zinc and its alloys as biodegradable metals. These preliminary in vitro and in vivo studies showed acceptable biodegradability and reasonable biocompatibility in bone and blood microenvironments for the experimental Zn-based biodegradable metals and, for some alloy systems, superior mechanical performance over Mg-based biodegradable metals. For instance, the Zn-Li alloys exhibited higher UTS (UTS), and the Zn-Mn alloys exhibited higher elongation (more than 100%). On the one hand, similar to Mg-based biodegradable metals, insufficient strength and ductility, as well as relatively low fatigue strength, may lead to premature failure of medical devices. On the other hand, owing to the low melting point of the element Zn, several new uncertainties with regard to the mechanical properties of biomedical zinc alloys, including low creep resistance, high susceptibility to natural aging, and static recrystallization (SRX), may lead to device failure during storage at room temperature and usage at body temperature. This paper comprehensively reviews studies on these mechanical aspects of industrial Zn and Zn alloys in the last century and biomedical Zn and Zn alloys in this century. The challenges for the future design of biomedical zinc alloys as biodegradable metals to guarantee 100% mechanical compatibility are pointed out, and this will guide the mechanical property design of Zn-based biodegradable metals. STATEMENT OF SIGNIFICANCE: Previous studies on mechanical properties of industrial Zn and Zn alloys in the last century and biomedical Zn and Zn alloys in this century are comprehensively reviewed herein. The challenges for the future design of zinc-based biodegradable materials considering mechanical compatibility are pointed out. Common considerations such as strength, ductility, and fatigue behaviors are covered together with special attention on several new uncertainties including low creep resistance, high susceptibility to natural aging, and static recrystallization (SRX). These new uncertainties, which are not significantly observed in Mg-based and Fe-based materials, are largely due to the low melting point of the element Zn and may lead to device failure during storage at room temperature and clinical usage at body temperature. Future studies are urgently needed on these topics.
Topics: Absorbable Implants; Alloys; Biocompatible Materials; Humans; Materials Testing; Tensile Strength; Zinc
PubMed: 31349057
DOI: 10.1016/j.actbio.2019.07.038 -
Materials Science & Engineering. C,... Nov 2021Biodegradable zinc (Zn) and Zn-based alloys have been recognized as promising biomaterials for biomedical implants. Sterilization is an essential step in handling...
Biodegradable zinc (Zn) and Zn-based alloys have been recognized as promising biomaterials for biomedical implants. Sterilization is an essential step in handling Zn-based implants before their use in clinical practice and there are various sterilization methods are available. However, how these treatments influence the Zn-based biomaterials remains unknown and is of critical relevance. In this study, three commonly-applied standard sterilization methods, namely gamma irradiation, hydrogen peroxide gas plasma and steam autoclave, were used on pure Zn and Zn3Cu (wt%) alloy. The treated Zn and ZnCu alloy were investigated to compare the different influences of sterilizations on surface characteristics, transient and long-term degradation behavior and cytotoxicity of Zn and Zn alloy. Our results indicate that autoclaving brought about apparently a formation of inhomogeneous zinc oxide film whereas the other two methods produced no apparent alterations on the material surfaces. Consequently, the samples after autoclaving showed significantly faster degradation rates and more severe localized corrosion, especially for the ZnCu alloy, owing to the incomplete covering and unstable zinc oxide layer. Moreover, the autoclave-treated Zn and ZnCu alloy exhibited apparent cytotoxic effects towards fibroblasts, which may be due to the excessive Zn ion releasing and its local concentration exceeds the cellular tolerance capacity. In contrast, gamma irradiation and hydrogen peroxide gas plasma had no apparent adverse effects on the biodegradability and cytocompatibility of Zn and ZnCu alloy. Our findings may have significant implications regarding the selection of suitable sterilization methods for Zn-based implant materials among others.
Topics: Absorbable Implants; Alloys; Biocompatible Materials; Corrosion; Materials Testing; Sterilization; Zinc
PubMed: 34702515
DOI: 10.1016/j.msec.2021.112430 -
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 -
Analytical Chemistry Dec 2022Electrochemistry has been used for decades to study materials' degradation in situ in corrosive environments, whether it is in room-temperature chemically aggressive... (Review)
Review
Electrochemistry has been used for decades to study materials' degradation in situ in corrosive environments, whether it is in room-temperature chemically aggressive solutions containing halide ions or in high-temperature oxidizing media such as pressurized water, liquid metals, or molten salts. Thus, following the recent surge in high-throughput techniques in materials science, it seems quite natural that high-throughput electrochemistry is being considered to study materials' degradation in extreme environments, with the objective to reduce corrosion resistant alloy development time by orders of magnitude and identify complex degradation mechanisms. However, while there has been considerable interest in the development of high-throughput methods for accelerating the discovery of corrosion resistant materials in different environments, these extreme environments propose formidable and exciting challenges for high-throughput electrochemical instrumentation, characterization, and data analysis. It is the objective of this paper to highlight those challenges, to present relatively new efforts to tackle them, and to develop research perspectives on the future of this exciting field. This Perspective is articulated around four main interconnected topics, which must be conjointly considered to enable corrosion resistant alloy design using high-throughput electrochemical methods: (1) high-throughput processing methods to develop material libraries, (2) high-throughput electrochemical methods for corrosion testing and evaluation, (3) high-throughput machine-learning augmented electrochemical data analysis, and (4) high-throughput autonomous electrochemistry representing the future of accelerated electrochemistry research.
Topics: Electrochemistry; Materials Testing; Corrosion; Alloys; Extreme Environments; Surface Properties
PubMed: 36419231
DOI: 10.1021/acs.analchem.2c03325 -
Environmental Science & Technology Jun 2023Vanadium is an element that is little known except to those who manufacture high-performance iron alloys and other widely used metal products that are indispensable for...
Vanadium is an element that is little known except to those who manufacture high-performance iron alloys and other widely used metal products that are indispensable for creating improved product performance across a variety of final-use sectors. We report here on deriving a detailed material flow cycle for vanadium in the United States for 1992-2021, the most recent year for which detailed data are available. The steels [tool steel, alloy steels, and high-strength low-alloy (HSLA) steels] are responsible for about half of the cumulative vanadium demand (167 Gg), with significantly smaller fractions being used to create catalysts, titanium-vanadium alloys, and several smaller product groups. These products flow to five end-use sectors, transport (61 Gg) and industrial machinery (62 Gg) being the largest. At end of product life, the vanadium-containing tool steels and catalysts are largely recycled, while most of the vanadium in carbon steels, alloy steels, HSLA steels, and other vanadium use sectors is functionally lost.
Topics: United States; Vanadium; Alloys; Steel; Titanium; Carbon
PubMed: 37285165
DOI: 10.1021/acs.est.3c01009