Translational status of biomedical Mg devices in China

Novel ternary Zn–Ca–Cu alloys were studied for the development of absorbable wound closure device material due to Ca and Cu's therapeutic values to wound healing. The influence of Ca and Cu on the microstructure, mechanical and degradation properties of Zn were investigated in the as-cast state to establish the fundamental understanding on the Zn–Ca–Cu alloy system. The microstructure of Zn-0.5Ca-0.5Cu, Zn-1.0Ca-0.5Cu, and Zn0.5Ca-1.0Cu is composed of intermetallic phase CaZn 13 distributed within the Zn–Cu solid solution. The presence of CaZn 13 phase and Cu as solute within the Zn matrix, on the one hand, exhibited a synergistic effect on the grain refinement of Zn, reducing the grain size of pure Zn by 96%; on the other hand, improved the mechanical properties of the ternary alloys through solid solution strengthening, second phase strengthening, and grain refinement. The degradation properties of Zn–Ca–Cu alloys are primarily influenced by the micro-galvanic corrosion between Zn–Cu matrix and CaZn 13 phase, where the 0.5% and 1.0% Ca addition increased the corrosion rate of Zn from 11.5 μm/y to 19.8 μm/y and 29.6 μm/y during 4 weeks immersion test.

Section: Introductionmentioning

confidence: 99%

The influence of Ca and Cu additions on the microstructure, mechanical and degradation properties of Zn–Ca–Cu alloys for absorbable wound closure device applications

Yang

Balasubramani

Venezuela

et al. 2021

“…In most Mg alloys, it was almost impossible to promote overall performance including strength and corrosion resistance, and biocompatibility for biomedical by adding alloy elements. Some researchers and companies had to choose HPM without any alloying elements for clinical application to ensure biosafety and a stable degradation, although scarified the mechanical property [ 38 ]. In present work, the novel lean alloy of bulk Z2 with particular nanocrystals could coordinate the contradiction among strength, corrosion resistance, and biocompatibility.…”

Section: Discussionmentioning

confidence: 99%

A novel lean alloy of biodegradable Mg–2Zn with nanograins

Wang

Blawert

Zan

et al. 2021

Self Cite

Lean alloy (low alloyed) is beneficial for long-term sustainable development of metal materials. Creating a nanocrystalline microstructure is a desirable approach to improve biodegradability and mechanical properties of lean biomedical Mg alloy, but it is nearly impossible to realize. In the present study, the bulk nanocrystalline Mg alloy (average grain size: ~70 nm) was successfully obtained by hot rolling process of a lean Mg-2wt.%Zn (Z2) alloy and both high strength ((223 MPa (YS) and 260 MPa (UTS)) and good corrosion resistance (corrosion rate in vivo: 0.2 mm/year) could be achieved. The microstructure evolution during the rolling process was analyzed and discussed. Several factors including large strain, fine grains, strong basal texture, high temperature and Zn segregation conjointly provided the possibility for the activation of pyramidal slip to produce nanocrystals. This finding could provide a new development direction and field of application for lean biomedical Mg alloys.

“…However, large volume of bone loss caused by serious trauma, infection, tumor resection and other injuries, might exceed the self-repair capacity, leading to bone defects [ 4 ]. Autogeous bone graft has been the “gold standard” for bone defect treatment, given its excellent performance in osteogenesis, osteoconduction and osteoinduction [ [5] , [6] , [7] , [8] ]. However, the wide application is limited by the incidence of infection, pain and hematoma at the defect site [ 9 ].…”

Section: Introductionmentioning

confidence: 99%

Biodegradable metals for bone defect repair: A systematic review and meta-analysis based on animal studies

Zhang

Jiang

Shang

et al. 2021

Biodegradable metals are promising candidates for bone defect repair. With an evidence-based approach, this study investigated and analyzed the performance and degradation properties of biodegradable metals in animal models for bone defect repair to explore their potential clinical translation. Animal studies on bone defect repair with biodegradable metals in comparison with other traditional biomaterials were reviewed. Data was carefully collected after identification of population, intervention, comparison, outcome, and study design (PICOS), and following the inclusion criteria of biodegradable metals in animal studies. 30 publications on pure Mg, Mg alloys, pure Zn and Zn alloys were finally included after extraction from a collected database of 2543 publications. A qualitative systematic review and a quantitative meta-analysis were performed. Given the heterogeneity in animal model, anatomical site and critical size defect (CSD), biodegradable metals exhibited mixed effects on bone defect repair and degradation in animal studies in comparison with traditional non-degradable metals, biodegradable polymers, bioceramics, and autogenous bone grafts. The results indicated that there were limitations in the experimental design of the included studies, and quality of the evidence presented by the studies was very low. To enhance clinical translation of biodegradable metals, evidence-based research with data validity is needed. Future studies should adopt standardized experimental protocols in investigating the effects of biodegradable metals on bone defect repair with animal models.