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Journal of Biomaterials Applications May 2021Niobium (Nb), Titanium (Ti), and Zirconium (Zr) have attracted much attention as implant materials due to it's excellent mechanical properties and biocompatibility....
Niobium (Nb), Titanium (Ti), and Zirconium (Zr) have attracted much attention as implant materials due to it's excellent mechanical properties and biocompatibility. However, little attention has been paid to high Nb-containing biomedical alloys. Here, the 50 wt.%Nb-XTi-Zr ternary alloy(x = 20wt.%, 30 wt.%, 40 wt.%) with relative density over 90% was prepared by powder metallurgy method. The massive α(Zr) distributed along the grain boundaries and lamellar β(Zr) appeared in the grains of β(Nb) in the 50 wt.%Nb-20wt.%Ti-Zr alloy. The acicular α phase is mainly distributed in the β-grain of 50 wt.%Nb-30wt.%Ti-Zr alloy. And α(Ti)-colonies in the β-grains and continuous α(Ti) at β-grain boundary can be observed in the 50 wt.%Nb-40wt.%Ti-Zr alloy. Comparing with Nb-20wt.%Ti-Zr alloy and 50 wt.%Nb-40wt.%Ti-Zr alloy, the 50 wt.%Nb-30wt.%Ti-Zr alloy showed lower Vickers hardness and elastic modulus. Furthermore, the as-sintered 50 wt.%Nb-XTi-Zr alloy promoted the cell proliferation and cell adhesion of MG-63 cells on the surface of alloys. In conclusion, the 50 wt.%Nb-XTi-Zr alloy combines excellent mechanical and biological properties, and the 50 wt.%Nb-30wt.%Ti-Zr alloy with lower elastic modulus (close to the bone) is a more promising candidate for bone implant material.
Topics: Alloys; Biocompatible Materials; Cell Adhesion; Cell Line; Cell Proliferation; Elastic Modulus; Hardness; Humans; Niobium; Prostheses and Implants; Titanium; Zirconium
PubMed: 33148099
DOI: 10.1177/0885328220970756 -
ACS Sensors Feb 2022Low melting point metals and alloys are the group of materials that combine metallic and liquid properties, simultaneously. The fascinating characteristics of liquid... (Review)
Review
Low melting point metals and alloys are the group of materials that combine metallic and liquid properties, simultaneously. The fascinating characteristics of liquid metals (LMs) including softness and high electrical and thermal conductivity, as well as their unique interfacial chemistry, have started to dominate various research disciplines. Utilization of LMs as responsive interfaces, enabling sensing in a flexible and versatile manner, is one of the most promising traits demonstrated for LMs. In the context of LMs-enabled sensors, gallium (Ga) and its alloys have emerged as multipurpose functional materials with many compelling physical and chemical properties. Responsiveness to different stimuli and easy-to-functionalize interfaces of Ga-based LMs make them ideal candidates for a variety of sensing applications. However, despite the vast capabilities of Ga-based LMs in sensing, applications of these materials for developing different sensors have not been fully explored. In the present review, we provide a comprehensive overview regarding the applications of Ga-based LMs in a wide range of sensing approaches that cover different physical and chemical sensors. The unique features of Ga-based LMs, which make them promising materials for sensing, are discussed in subsections followed by relevant case studies. Finally, challenges as well as the prospected future and developing motifs are highlighted for each type of LM-based sensors.
Topics: Alloys; Gallium
PubMed: 35119830
DOI: 10.1021/acssensors.1c02606 -
Biomaterials Dec 2021Shape memory alloys (SMAs) have a wide range of potential novel medical applications due to their superelastic properties and ability to restore and retain a 'memorised'... (Review)
Review
Shape memory alloys (SMAs) have a wide range of potential novel medical applications due to their superelastic properties and ability to restore and retain a 'memorised' shape. However, most SMAs are permanent and do not degrade in the body when used in implantable devices. The use of non-degrading metals may lead to the requirement for secondary removal surgery and this in turn may introduce both short and long-term health risks, or additional waste disposal requirements. Biodegradable SMAs can effectively eliminate these issues by gradually degrading inside the human body while providing the necessary support for healing purposes, therefore significantly alleviating patient discomfort and improving healing efficiency. This paper reviews the current progress in biodegradable SMAs from the perspective of biodegradability, mechanical properties, and biocompatibility. By providing insights into the status of SMAs and biodegradation mechanisms, the prospects for Mg- and Fe-based biodegradable SMAs to advance biodegradable SMA-based medical devices are explored. Finally, the remaining challenges and potential solutions in the biodegradable SMAs area are discussed, providing suggestions and research frameworks for future studies on this topic.
Topics: Alloys; Biocompatible Materials; Humans; Metals; Prostheses and Implants; Shape Memory Alloys
PubMed: 34736144
DOI: 10.1016/j.biomaterials.2021.121215 -
Sensors (Basel, Switzerland) Sep 2022Ever since its discovery, the applications of Shape Memory Alloys (SMA) can be found across a range of application domains, from structural design to medical technology.... (Review)
Review
Ever since its discovery, the applications of Shape Memory Alloys (SMA) can be found across a range of application domains, from structural design to medical technology. This is based upon the unique and inherent characteristics such as thermal Shape Memory Effect (SME) and Superelasticity (or Pseudoelasticity). While thermal SME is used for shape morphing applications wherein temperature change can govern the shape and dimension of the SMA, Superelasticity allows the alloy to withstand a comparatively very high magnitude of loads without undergoing plastic deformation at higher temperatures. These unique properties in wearables have revolutionized the field, and from fabrics to exoskeletons, SMA has found its place in robotics and cobotics. This review article focuses on the most recent research work in the field of SMA-based smart wearables paired with robotic applications for human-robot interaction. The literature is categorized based on SMA property incorporated and on actuator or sensor-based concept. Further, use-cases or conceptual frameworks for SMA fiber in fabric for '' and SMA springs in the shoe soles for '' are proposed. The conceptual frameworks are built upon existing technologies; however, their utility in a smart factory concept is emphasized, and algorithms to achieve the same are proposed. The integration of the two concepts with the Industrial Internet of Things (IIoT) is discussed, specifically regarding minimizing hazards for the worker/user in Industry 5.0. The article aims to propel a discussion regarding the multi-faceted applications of SMAs in human-robot interaction and Industry 5.0. Furthermore, the challenges and the limitations of the smart alloy and the technological barriers restricting the growth of SMA applications in the field of smart wearables are observed and elaborated.
Topics: Alloys; Humans; Plastics; Robotics; Shape Memory Alloys; Wearable Electronic Devices
PubMed: 36146151
DOI: 10.3390/s22186802 -
Regulatory Toxicology and Pharmacology... Aug 2022Stainless steels are widely used iron-based alloys that contain chromium and, typically, other alloying elements. The chromium(III)-rich surface oxide of stainless... (Review)
Review
Stainless steels are widely used iron-based alloys that contain chromium and, typically, other alloying elements. The chromium(III)-rich surface oxide of stainless steels efficiently limits the release (bioaccessibility) of their metal constituents in most physiological environments, influencing the toxicity of the alloy. Of the constituents and impurities of stainless steels, nickel and cobalt are of particular interest, primarily due to skin sensitization and repeated-dose inhalation toxicity of nickel, and (inhalation) carcinogenicity of cobalt. A review of the available toxicological data on stainless steels, and the toxicological, mechanistic, and bioaccessibility data on their constituent metals supports the low toxicity and non-carcinogenicity of stainless steels. The comparative metal release, rather than the bulk composition of stainless steels, needs to be considered when assessing their health hazard classification according to the UN Globally Harmonized System, and the corresponding EU CLP regulation. As an illustrative example, a 28-day inhalation toxicity study on stainless steel powder showed no signs of lung toxicity at exposure levels at which significant toxicity would have been expected on the basis of its bulk nickel content. This finding is associated with the low bioaccessibility of nickel from the alloy in the lungs.
Topics: Alloys; Chromium; Cobalt; Nickel; Stainless Steel; Steel
PubMed: 35817207
DOI: 10.1016/j.yrtph.2022.105227 -
Frontiers in Cellular and Infection... 2021Implants are widely used in orthopedic surgery and are gaining attention of late. However, their use is restricted by implant-associated infections (IAI), which... (Review)
Review
Implants are widely used in orthopedic surgery and are gaining attention of late. However, their use is restricted by implant-associated infections (IAI), which represent one of the most serious and dangerous complications of implant surgeries. Various strategies have been developed to prevent and treat IAI, among which the closest to clinical translation is designing metal materials with antibacterial functions by alloying methods based on existing materials, including titanium, cobalt, tantalum, and biodegradable metals. This review first discusses the complex interaction between bacteria, host cells, and materials in IAI and the mechanisms underlying the antibacterial effects of biomedical metals and alloys. Then, their applications for the prevention and treatment of IAI are highlighted. Finally, new insights into their clinical translation are provided. This review also provides suggestions for further development of antibacterial metals and alloys.
Topics: Alloys; Anti-Bacterial Agents; Metals; Titanium
PubMed: 34277473
DOI: 10.3389/fcimb.2021.693939 -
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 -
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 -
Acta Biomaterialia May 2016With a continuously increasing aging population and the improvement of living standards, large demands of biomaterials are expected for a long time to come. Further... (Review)
Review
UNLABELLED
With a continuously increasing aging population and the improvement of living standards, large demands of biomaterials are expected for a long time to come. Further development of novel biomaterials, that are much safer and of much higher quality, in terms of both biomedical and mechanical properties, are therefore of great interest for both the research scientists and clinical surgeons. Compared with the conventional crystalline metallic counterparts, bulk metallic glasses have unique amorphous structures, and thus exhibit higher strength, lower Young's modulus, improved wear resistance, good fatigue endurance, and excellent corrosion resistance. For this purpose, bulk metallic glasses (BMGs) have recently attracted much attention for biomedical applications. This review discusses and summarizes the recent developments and advances of bulk metallic glasses, including Ti-based, Zr-based, Fe-based, Mg-based, Zn-based, Ca-based and Sr-based alloying systems for biomedical applications. Future research directions will move towards overcoming the brittleness, increasing the glass forming ability (GFA) thus obtaining corresponding bulk metallic glasses with larger sizes, removing/reducing toxic elements, and surface modifications.
STATEMENT OF SIGNIFICANCE
Bulk metallic glasses (BMGs), also known as amorphous alloys or liquid metals, are relative newcomers in the field of biomaterials. They have gained increasing attention during the past decades, as they exhibit an excellent combination of properties and processing capabilities desired for versatile biomedical implant applications. The present work reviewed the recent developments and advances of biomedical BMGs, including Ti-based, Zr-based, Fe-based, Mg-based, Zn-based, Ca-based and Sr-based BMG alloying systems. Besides, the critical analysis and in-depth discussion on the current status, challenge and future development of biomedical BMGs are included. The possible solution to the BMG size limitation, the brittleness of BMGs has been proposed.
Topics: Alloys; Biocompatible Materials; Biomedical Technology; Glass; Metals; Prostheses and Implants
PubMed: 27045349
DOI: 10.1016/j.actbio.2016.03.047