The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform

Yufeng Zheng - One of the best experts on this subject based on the ideXlab platform.

  • zn0 8li0 1sr a Biodegradable Metal with high mechanical strength comparable to pure ti for the treatment of osteoporotic bone fractures in vitro and in vivo studies
    Biomaterials, 2021
    Co-Authors: Zechuan Zhang, Bo Jia, Hongtao Yang, Yu Han, Kerong Dai, Yufeng Zheng
    Abstract:

    Abstract The first in vivo investigation of Zn-based Biodegradable Metal aiming to treat osteoporotic bone fractures, a soaring threat to human health, is reported in this paper. Among the newly developed Biodegradable Metal system (ZnLiSr), Zn0.8Li0.1Sr exhibits excellent comprehensive mechanical properties, with an ultimate tensile strength (524.33 ± 18.01 MPa) comparable to pure Ti (the gold standard for orthopaedic implants), and a strength-ductility balance over 10 GPa%. The in vitro degradation tests using simulated body fluid (SBF) shows that Zn0.8Li0.1Sr manifests a uniform degradation morphology and smaller corrosion pits , with a degradation rate of 10.13 ± 1.52 μm year −1. Real-time PCR and western blotting illustrated that Zn0.8Li0.1Sr successfully stimulated the expression of critical osteogenesis-related genes (ALP, COL-1, OCN and Runx-2) and proteins. Twenty-four weeks’ in vivo implantations within ovariectomized (OVX) rats were conducted to evaluate the osteoporotic-bone-fracture-treating effects of Zn0.8Li0.1Sr, with pure Ti as control group. Micro-CT, histological and immunohistochemical evaluations all revealed that Zn0.8Li0.1Sr possesses a similar biosafety level to, while significantly superior osteogenesis-inducing and osteoporotic-bone-fracture-treating effects than pure Ti. ZnLiSr Biodegradable alloys manifest excellent comprehensive mechanical properties, good biosafety and osteoporotic-bone-fracture-treating effects, which would provide preferable choices for future medical applications, especially in load-bearing positions.

  • Biodegradable Metal derived magnesium and sodium enhances bone regeneration by angiogenesis aided osteogenesis and regulated biological apatite formation
    Chemical Engineering Journal, 2021
    Co-Authors: Ling Qin, Yang Liu, Jessica Terbush, Mohan Setty, Shaokang Guan, Thanh D Nguyen, Yufeng Zheng
    Abstract:

    Abstract Biodegradable Metals have great attraction to become orthopaedic implants. Here, we demonstrated a Biodegradable magnesium alloy incorporated with essential element sodium through Sn-Na master alloying technique. The designed MgSnZnNa alloy presented better hardness and corrosion resistance due to the uniform distribution of Na in Mg2Sn second phase and solid soluble Zn in Mg matrix. The co-release of Mg and Na ions resulted in advanced upregulation of osterix and osteocalcin expression in adipose derived stem cells in vitro. It significantly promoted the rat calvarial defect bone regeneration through osteogenesis and angiogenesis, attributed to the co-release of Na and Mg ions, by increasing the expression of calcitonin gene-related peptide, osteocalcin as well as vascular endothelial growth factor. The current study provided an innovative approach by using master alloy to incorporate essential elements (such as Na or K) for fabricating Biodegradable Mg alloys with reduced galvanic corrosion and enhanced biological functions.

  • enhanced cytocompatibility and antibacterial property of zinc phosphate coating on Biodegradable zinc materials
    Acta Biomaterialia, 2019
    Co-Authors: Kai Wang, Yufeng Zheng, Julia Gao, Yong Yang, Yixian Qin, Donghui Zhu
    Abstract:

    Zinc (Zn) has recently emerged as a promising Biodegradable Metal thanks to its critical physiological roles and promising degradation behavior. However, cytocompatibility and antibacterial property of Zn is still suboptimal, in part, due to the excessive Zn ions released during degradation. Inspired by the calcium phosphate-based minerals in natural bone tissue, zinc phosphate (ZnP) coatings were prepared on pure Zn using a chemical conversion method in this study. The coating morphology was then optimized through controlling the pH of coating solution, resulting in a homogeneous micro-/nano-ZnP coating structure. The ZnP coating significantly increased the cell viability, adhesion, and differentiation of pre-osteoblasts and vascular endothelial cells, while significantly reduced the adhesion of the platelets and E. coli. Additionally, ZnP coating significantly reduced the Zn ion release from the bulk material during degradation process, resulting in a much lower Zn2+ concentration and pH change in the surrounding environment. The improved hemocompatibility, cytocompatibility and antibacterial performance of ZnP coated Zn biomaterials could be mainly attributed to the controlled Zn ion release and micro-/nano-scaled coating structure. Taken together, ZnP coating on Zn-based biomaterial appears to be a viable approach to enhance its biocompatibility and antibacterial property as well as to control its degradation rate. Statement of Significance Zn and its alloys are promising Biodegradable implant materials for orthopedic and cardiovascular applications. However, notable cytotoxicity has been reported due to degradation products accumulated in the local environment, largely overdosed Zn2+. Thus, controlling burst Zn2+ release is the key to minimize the toxicity of Zn implants. To achieve this goal, we prepared a homogenous ZnP coating on Zn Metals thanks to its easy synthesis, stable chemical property, and good biocompatibility. Results showed that ZnP not only improved the cell viability, adhesion and proliferation, but also significantly reduced the attachment of platelet and bacterial. Therefore, ZnP could be a promising approach to improve the functional performance of Zn-based implants, and potentially be applied to many other medical implants.

  • in vitro and in vivo studies on zinc hydroxyapatite composites as novel Biodegradable Metal matrix composite for orthopedic applications
    Acta Biomaterialia, 2018
    Co-Authors: Hongtao Yang, Yufeng Zheng, Xinhua Qu, Cong Wang
    Abstract:

    Abstract Recent studies indicate that there is a great demand to optimize pure Zn with tunable degradation rates and more desirable biocompatibility as orthopedic implants. Metal matrix composite (MMC) can be a promising approach for this purpose. In this study, MMC with pure Zn as a matrix and hydroxyapatite (HA) as reinforcements were prepared by spark plasma sintering (SPS). Feasibility of novel Zn-HA composites to be used as orthopedic implant applications was systematically evaluated. After sintering, HA distributed in the Zn particle boundaries uniformly. Corrosion tests indicated that the degradation rates of Zn-HA composites were adjustable due to the biphasic effects of HA. Zn-HA composites showed significantly improved cell viability of osteoblastic MC3T3-E1 cells compared with pure Zn. Both pure Zn and composites exhibited a low thrombosis risk and hemolysis rates while a Zn ion concentration-dependent effect was found on coagulation time. An effective antibacterial property was observed as well. The volume loss of pure Zn and Zn-5HA composite was 1.7% and 3.2% after 8 weeks’ implantation. Histological analysis found newly formed bone surrounding pure Zn and Zn-5HA composite at week 4 and increased bone mass over time. With prolonged implantation time, Zn-5HA composite was more effective on stimulating new bone formation than pure Zn. In summary, MMC is a feasible way to design Zn based materials with adjustable degradation rates and improved biocompatibility. Statement of Significance Biodegradable zinc materials are promising candidates for the new generation of orthopedic implants. However, the slow degradation rates and unsatisfactory cytocompatibility of pure Zn in bone environments limit its future clinical applications. Generally, alloying is a common way to improve the performance of pure Zn. In this study, Metal matrix composite was chosen as a novel strategy to solve the problems. Hydroxyapatite, as a bioactive component, was added into Zn matrix via spark plasma sintering. We find that Zn-HA composites exhibited adjustable degradation rates and improved biocompatibility both in vitro and in vivo. This study provides exhaustive and significant information including microstructure, mechanical performance, degradation behavior, biocompatibility, hemocompatibility and antibacterial property for the future Zn based implants design.

  • in vitro and in vivo studies on zinc hydroxyapatite composites as novel Biodegradable Metal matrix composite for orthopedic applications
    Acta Biomaterialia, 2018
    Co-Authors: Hongtao Yang, Yufeng Zheng, Donghui Zhu, Kerong Dai, Cong Wang, Wenjiao Lin
    Abstract:

    Abstract Recent studies indicate that there is a great demand to optimize pure Zn with tunable degradation rates and more desirable biocompatibility as orthopedic implants. Metal matrix composite (MMC) can be a promising approach for this purpose. In this study, MMC with pure Zn as a matrix and hydroxyapatite (HA) as reinforcements were prepared by spark plasma sintering (SPS). Feasibility of novel Zn-HA composites to be used as orthopedic implant applications was systematically evaluated. After sintering, HA distributed in the Zn particle boundaries uniformly. Corrosion tests indicated that the degradation rates of Zn-HA composites were adjustable due to the biphasic effects of HA. Zn-HA composites showed significantly improved cell viability of osteoblastic MC3T3-E1 cells compared with pure Zn. Both pure Zn and composites exhibited a low thrombosis risk and hemolysis rates while a Zn ion concentration-dependent effect was found on coagulation time. An effective antibacterial property was observed as well. The volume loss of pure Zn and Zn-5HA composite was 1.7% and 3.2% after 8 weeks’ implantation. Histological analysis found newly formed bone surrounding pure Zn and Zn-5HA composite at week 4 and increased bone mass over time. With prolonged implantation time, Zn-5HA composite was more effective on stimulating new bone formation than pure Zn. In summary, MMC is a feasible way to design Zn based materials with adjustable degradation rates and improved biocompatibility. Statement of Significance Biodegradable zinc materials are promising candidates for the new generation of orthopedic implants. However, the slow degradation rates and unsatisfactory cytocompatibility of pure Zn in bone environments limit its future clinical applications. Generally, alloying is a common way to improve the performance of pure Zn. In this study, Metal matrix composite was chosen as a novel strategy to solve the problems. Hydroxyapatite, as a bioactive component, was added into Zn matrix via spark plasma sintering. We find that Zn-HA composites exhibited adjustable degradation rates and improved biocompatibility both in vitro and in vivo. This study provides exhaustive and significant information including microstructure, mechanical performance, degradation behavior, biocompatibility, hemocompatibility and antibacterial property for the future Zn based implants design.

Ling Qin - One of the best experts on this subject based on the ideXlab platform.

  • Biodegradable Metal derived magnesium and sodium enhances bone regeneration by angiogenesis aided osteogenesis and regulated biological apatite formation
    Chemical Engineering Journal, 2021
    Co-Authors: Ling Qin, Yang Liu, Jessica Terbush, Mohan Setty, Shaokang Guan, Thanh D Nguyen, Yufeng Zheng
    Abstract:

    Abstract Biodegradable Metals have great attraction to become orthopaedic implants. Here, we demonstrated a Biodegradable magnesium alloy incorporated with essential element sodium through Sn-Na master alloying technique. The designed MgSnZnNa alloy presented better hardness and corrosion resistance due to the uniform distribution of Na in Mg2Sn second phase and solid soluble Zn in Mg matrix. The co-release of Mg and Na ions resulted in advanced upregulation of osterix and osteocalcin expression in adipose derived stem cells in vitro. It significantly promoted the rat calvarial defect bone regeneration through osteogenesis and angiogenesis, attributed to the co-release of Na and Mg ions, by increasing the expression of calcitonin gene-related peptide, osteocalcin as well as vascular endothelial growth factor. The current study provided an innovative approach by using master alloy to incorporate essential elements (such as Na or K) for fabricating Biodegradable Mg alloys with reduced galvanic corrosion and enhanced biological functions.

  • in vitro and in vivo studies on as extruded mg 5 25wt zn 0 6wt ca alloy as Biodegradable Metal
    Science China. Materials, 2018
    Co-Authors: Fan Wang, Yufeng Zheng, Xinhui Xie, Mingyi Zheng, Ling Qin, Yubo Fan
    Abstract:

    Magnesium alloys have shown prospective applications as a new Biodegradable Metal within bone. To garantee the longterm biocompatibility, a Mg-Zn-Ca alloy, composing of essential elements for human, was prepared and its feasibility for orthopedic applications was investigated. The in vitro and in vivo corrosion of Mg-Zn-Ca alloy as well as the biocompatibility were studied. The in vitro corrosion tests in five kinds of physiological solutions showed that the corrosion rates and corrosion morphologies of the alloy were strongly influenced by the solution used. The addition of serum in Hank’s and MEM significantly slowed down the corrosion rate and improved the corrosion uniformity of the alloy. The corrosion rate decreased with increasing serum concentration. The alloy showed the slowest corrosion rate as well as homogeneous corrosion morphology in MEM+10%FBS. Both the indirect and direct cell experiments indicated good cytocompatibility of the extruded Mg-Zn-Ca alloy. In vivo , we observed a gradual degradation process from the surface of extruded Mg-Zn-Ca alloy and only 40% in volume of implant was left after 4 weeks implantation in medullary cavities of mice. The micro-CT and histological analyses revealed its good biocompatibility with peri-implant new bone formation and increasing cortical bone thickness with increasing implantation period. This study showed that the extruded Mg-Zn-Ca alloy provided sufficient biocompatibility for orthopedic application, though the in vivo corrosion rate should be further reduced for clinical use.

  • Biodegradable magnesium screws accelerate fibrous tissue mineralization at the tendon bone insertion in anterior cruciate ligament reconstruction model of rabbit
    Scientific Reports, 2017
    Co-Authors: Jiali Wang, Ling Qin, Wenxiang Cheng, Kaiming Chan, Patrick Shuhang Yung
    Abstract:

    The incorporation of tendon graft into bone tunnel is one of the most challenging clinical issues in anterior cruciate ligament (ACL) reconstruction. As a Biodegradable Metal, Mg has appropriate mechanical strength and osteoinductive effects, thus may be a promising alternative to commercialized products used for graft fixation. Therefore, it was hypothesized that Mg based interference screws would promote tendon graft-bone junction healing when compared to Ti screws. Herein, we compared the effects of Mg and Ti screws on tendon graft healing in rabbits with ACL reconstruction via histological, HR-pQCT and mechanical analysis. The histological results indicated that Mg screws significantly improved the graft healing quality via promoting mineralization at the tendon graft enthesis. Besides, Mg screws significantly promoted bone formation in the peri-screw region at the early healing stage. Importantly, Mg screws exhibited excellent corrosion resistance and the degradation of Mg screws did not induce bone tunnel widening. In tensile testing, there were no significant differences in the load to failure, stress, stiffness and absorption energy between Mg and Ti groups due to the failure mode at the midsubstance. Our findings demonstrate that Mg screws can promote tendon graft healing after ACL reconstruction, implying a potential alternative to Ti screws for clinical applications.

  • development of Biodegradable zn 1x binary alloys with nutrient alloying elements mg ca and sr
    Scientific Reports, 2015
    Co-Authors: Xinhui Xie, F Y Zhou, Yufeng Zheng, K J Qiu, Yingying Cong, Xinluan Wang, Serena Chen, Li Huang, Li Tian, Ling Qin
    Abstract:

    Biodegradable Metals have attracted considerable attentions in recent years. Besides the early launched Biodegradable Mg and Fe Metals, Zn, an essential element with osteogenic potential of human body, is regarded and studied as a new kind of potential Biodegradable Metal quite recently. Unfortunately, pure Zn is soft, brittle and has low mechanical strength in the practice, which needs further improvement in order to meet the clinical requirements. On the other hand, the widely used industrial Zn-based alloys usually contain biotoxic elements (for instance, ZA series contain toxic Al elements up to 40 wt.%), which subsequently bring up biosafety concerns. In the present work, novel Zn-1X binary alloys, with the addition of nutrition elements Mg, Ca and Sr were designed (cast, rolled and extruded Zn-1Mg, Zn-1Ca and Zn-1Sr). Their microstructure and mechanical property, degradation and in vitro and in vivo biocompatibility were studied systematically. The results demonstrated that the Zn-1X (Mg, Ca and Sr) alloys have profoundly modified the mechanical properties and biocompatibility of pure Zn. Zn-1X (Mg, Ca and Sr) alloys showed great potential for use in a new generation of Biodegradable implants, opening up a new avenue in the area of Biodegradable Metals.

  • in vitro and in vivo studies on a mg sr binary alloy system developed as a new kind of Biodegradable Metal
    Acta Biomaterialia, 2012
    Co-Authors: Yufeng Zheng, Xinhui Xie, Ling Qin
    Abstract:

    Magnesium alloys have shown potential as Biodegradable Metallic materials for orthopedic applications due to their degradability, resemblance to cortical bone and biocompatible degradation/corrosion products. However, the fast corrosion rate and the potential toxicity of their alloying element limit the clinical application of Mg alloys. From the viewpoint of both Metallurgy and biocompatibility, strontium (Sr) was selected to prepare hot rolled Mg-Sr binary alloys (with a Sr content ranging from 1 to 4 wt.%) in the present study. The optimal Sr content was screened with respect to the mechanical and corrosion properties of Mg-Sr binary alloys and the feasibility of the use of Mg-Sr alloys as orthopedic Biodegradable Metals was investigated by in vitro cell experiments and intramedullary implantation tests. The mechanical properties and corrosion rates of Mg-Sr alloys were dose dependent with respect to the added Sr content. The as-rolled Mg-2Sr alloy exhibited the highest strength and slowest corrosion rate, suggesting that the optimal Sr content was 2 wt.%. The as-rolled Mg-2Sr alloy showed Grade I cytotoxicity and induced higher alkaline phosphatase activity than the other alloys. During the 4 weeks implantation period we saw gradual degradation of the as-rolled Mg-2Sr alloy within a bone tunnel. Micro-computer tomography and histological analysis showed an enhanced mineral density and thicker cortical bone around the experimental implants. Higher levels of Sr were observed in newly formed peri-implant bone compared with the control. In summary, this study shows that the optimal content of added Sr is 2 wt.% for binary Mg-Sr alloys in the rolled state and that the as-rolled Mg-2Sr alloy in vivo produces an acceptable host response.

Hongtao Yang - One of the best experts on this subject based on the ideXlab platform.

  • zn0 8li0 1sr a Biodegradable Metal with high mechanical strength comparable to pure ti for the treatment of osteoporotic bone fractures in vitro and in vivo studies
    Biomaterials, 2021
    Co-Authors: Zechuan Zhang, Bo Jia, Hongtao Yang, Yu Han, Kerong Dai, Yufeng Zheng
    Abstract:

    Abstract The first in vivo investigation of Zn-based Biodegradable Metal aiming to treat osteoporotic bone fractures, a soaring threat to human health, is reported in this paper. Among the newly developed Biodegradable Metal system (ZnLiSr), Zn0.8Li0.1Sr exhibits excellent comprehensive mechanical properties, with an ultimate tensile strength (524.33 ± 18.01 MPa) comparable to pure Ti (the gold standard for orthopaedic implants), and a strength-ductility balance over 10 GPa%. The in vitro degradation tests using simulated body fluid (SBF) shows that Zn0.8Li0.1Sr manifests a uniform degradation morphology and smaller corrosion pits , with a degradation rate of 10.13 ± 1.52 μm year −1. Real-time PCR and western blotting illustrated that Zn0.8Li0.1Sr successfully stimulated the expression of critical osteogenesis-related genes (ALP, COL-1, OCN and Runx-2) and proteins. Twenty-four weeks’ in vivo implantations within ovariectomized (OVX) rats were conducted to evaluate the osteoporotic-bone-fracture-treating effects of Zn0.8Li0.1Sr, with pure Ti as control group. Micro-CT, histological and immunohistochemical evaluations all revealed that Zn0.8Li0.1Sr possesses a similar biosafety level to, while significantly superior osteogenesis-inducing and osteoporotic-bone-fracture-treating effects than pure Ti. ZnLiSr Biodegradable alloys manifest excellent comprehensive mechanical properties, good biosafety and osteoporotic-bone-fracture-treating effects, which would provide preferable choices for future medical applications, especially in load-bearing positions.

  • in vitro and in vivo studies on zinc hydroxyapatite composites as novel Biodegradable Metal matrix composite for orthopedic applications
    Acta Biomaterialia, 2018
    Co-Authors: Hongtao Yang, Yufeng Zheng, Xinhua Qu, Cong Wang
    Abstract:

    Abstract Recent studies indicate that there is a great demand to optimize pure Zn with tunable degradation rates and more desirable biocompatibility as orthopedic implants. Metal matrix composite (MMC) can be a promising approach for this purpose. In this study, MMC with pure Zn as a matrix and hydroxyapatite (HA) as reinforcements were prepared by spark plasma sintering (SPS). Feasibility of novel Zn-HA composites to be used as orthopedic implant applications was systematically evaluated. After sintering, HA distributed in the Zn particle boundaries uniformly. Corrosion tests indicated that the degradation rates of Zn-HA composites were adjustable due to the biphasic effects of HA. Zn-HA composites showed significantly improved cell viability of osteoblastic MC3T3-E1 cells compared with pure Zn. Both pure Zn and composites exhibited a low thrombosis risk and hemolysis rates while a Zn ion concentration-dependent effect was found on coagulation time. An effective antibacterial property was observed as well. The volume loss of pure Zn and Zn-5HA composite was 1.7% and 3.2% after 8 weeks’ implantation. Histological analysis found newly formed bone surrounding pure Zn and Zn-5HA composite at week 4 and increased bone mass over time. With prolonged implantation time, Zn-5HA composite was more effective on stimulating new bone formation than pure Zn. In summary, MMC is a feasible way to design Zn based materials with adjustable degradation rates and improved biocompatibility. Statement of Significance Biodegradable zinc materials are promising candidates for the new generation of orthopedic implants. However, the slow degradation rates and unsatisfactory cytocompatibility of pure Zn in bone environments limit its future clinical applications. Generally, alloying is a common way to improve the performance of pure Zn. In this study, Metal matrix composite was chosen as a novel strategy to solve the problems. Hydroxyapatite, as a bioactive component, was added into Zn matrix via spark plasma sintering. We find that Zn-HA composites exhibited adjustable degradation rates and improved biocompatibility both in vitro and in vivo. This study provides exhaustive and significant information including microstructure, mechanical performance, degradation behavior, biocompatibility, hemocompatibility and antibacterial property for the future Zn based implants design.

  • in vitro and in vivo studies on zinc hydroxyapatite composites as novel Biodegradable Metal matrix composite for orthopedic applications
    Acta Biomaterialia, 2018
    Co-Authors: Hongtao Yang, Yufeng Zheng, Donghui Zhu, Kerong Dai, Cong Wang, Wenjiao Lin
    Abstract:

    Abstract Recent studies indicate that there is a great demand to optimize pure Zn with tunable degradation rates and more desirable biocompatibility as orthopedic implants. Metal matrix composite (MMC) can be a promising approach for this purpose. In this study, MMC with pure Zn as a matrix and hydroxyapatite (HA) as reinforcements were prepared by spark plasma sintering (SPS). Feasibility of novel Zn-HA composites to be used as orthopedic implant applications was systematically evaluated. After sintering, HA distributed in the Zn particle boundaries uniformly. Corrosion tests indicated that the degradation rates of Zn-HA composites were adjustable due to the biphasic effects of HA. Zn-HA composites showed significantly improved cell viability of osteoblastic MC3T3-E1 cells compared with pure Zn. Both pure Zn and composites exhibited a low thrombosis risk and hemolysis rates while a Zn ion concentration-dependent effect was found on coagulation time. An effective antibacterial property was observed as well. The volume loss of pure Zn and Zn-5HA composite was 1.7% and 3.2% after 8 weeks’ implantation. Histological analysis found newly formed bone surrounding pure Zn and Zn-5HA composite at week 4 and increased bone mass over time. With prolonged implantation time, Zn-5HA composite was more effective on stimulating new bone formation than pure Zn. In summary, MMC is a feasible way to design Zn based materials with adjustable degradation rates and improved biocompatibility. Statement of Significance Biodegradable zinc materials are promising candidates for the new generation of orthopedic implants. However, the slow degradation rates and unsatisfactory cytocompatibility of pure Zn in bone environments limit its future clinical applications. Generally, alloying is a common way to improve the performance of pure Zn. In this study, Metal matrix composite was chosen as a novel strategy to solve the problems. Hydroxyapatite, as a bioactive component, was added into Zn matrix via spark plasma sintering. We find that Zn-HA composites exhibited adjustable degradation rates and improved biocompatibility both in vitro and in vivo. This study provides exhaustive and significant information including microstructure, mechanical performance, degradation behavior, biocompatibility, hemocompatibility and antibacterial property for the future Zn based implants design.

  • design and characterizations of novel Biodegradable ternary zn based alloys with iia nutrient alloying elements mg ca and sr
    Materials & Design, 2015
    Co-Authors: Hongtao Yang, F Y Zhou, Yufeng Zheng, K J Qiu, Xiang Wang
    Abstract:

    Abstract Apart from the industrial and automotive applications, Zn and Zn-based alloys are considered as a new kind of potential Biodegradable material quite recently. However, one drawback of pure Zn as potential Biodegradable Metal lies in that pure Zn has quite low strength and plasticity. In the present study, three important IIA essential nutrient elements Mg, Ca and Sr and hot-rolling and hot-extrusion thermal deformations have been applied to overcome the drawback of pure Zn and benefit the biocompatibility of Zn-based potential implants. The microstructure, mechanical properties, corrosion behavior, hemocompatibility, in vitro cytocompatibility were studied systematically to investigate their feasibility as bioabsorbable implants. The results showed that the mechanical properties of the ternary Zn–1Mg–1Ca, Zn–1Mg–1Sr and Zn–1Ca–1Sr alloys are much higher than that of pure Zn, owing to both the alloying effects and thermal deformation effects. In vitro hemolytic rate test and cell viability test indicated that the addition of the IIA nutrient alloying elements Mg, Ca and Sr into Zn can benefit their hemocompatibility and cytocompatibility, which would further guarantee the biosafety of these new kind of Biodegradable Zn-based implants for future clinical applications.

Lobat Tayebi - One of the best experts on this subject based on the ideXlab platform.

  • Improvement of in vitro behavior of an Mg alloy using a nanostructured composite bioceramic coating
    Journal of Materials Science: Materials in Medicine, 2018
    Co-Authors: Mehdi Razavi, Mohammadhossein Fathi, Omid Savabi, Lobat Tayebi, Daryoosh Vashaee
    Abstract:

    Magnesium (Mg) alloys as a new group of Biodegradable Metal implants are being extensively investigated as a promising selection for biomaterials applications due to their apt mechanical and biological performance. However, as a foremost drawback of Mg alloys, the high degradation in body fluid prevents its clinical applications. In this work, a bioceramic composite coating is developed composed of diopside, bredigite, and fluoridated hydroxyapatite on the AZ91 Mg alloy in order to moderate the degradation rate, while improving its bioactivity, cell compatibility, and mechanical integrity. Microstructural studies were performed using a transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD) analysis, and energy dispersive spectroscopy (EDS). The degradation properties of samples were carried out under two steps, including electrochemical corrosion test and immersion test in simulated body fluid (SBF). Additionally, compression test was performed to evaluate the mechanical integrity of the specimens. L-929 fibroblast cells were cultured on the samples to determine the cell compatibility of the samples, including the cell viability and attachment. The degradation results suggest that the composite coating decreases the degradation and improves the bioactivity of AZ91 Mg alloy substrate. No considerable deterioration in the compression strength was observed for the coated samples compared to the uncoated sample after 4 weeks immersion. Cytotoxicity test indicated that the coatings improve the cell compatibility of AZ91 alloy for L-929 cells.

  • development and degradation behavior of magnesium scaffolds coated with polycaprolactone for bone tissue engineering
    Materials Letters, 2014
    Co-Authors: Mostafa Yazdimamaghani, Mehdi Razavi, Lobat Tayebi, Daryoosh Vashaee
    Abstract:

    Abstract Rapid degradation of magnesium (Mg) alloys is the major drawback preventing these materials from being applicable as tissue engineering scaffolds. In order to resolve this issue, in this paper, porous Mg scaffolds coated by polycaprolactone (PCL) were synthesized and their material properties and in vitro biodegradation were fully examined. The results indicated that PCL coating can significantly enhance the compressive strength and degradation resistance of Mg scaffolds. We showed that while the uncoated Mg scaffold degrades completely (100% weight loss) after 72 h, the degradation (weight loss) of the Mg scaffolds coated by 3% and 6% PCL is only 36% and 23%, respectively. Thus PCL-coated Mg scaffolds, as a Biodegradable Metal scaffold, can potentially have a promising application in bone tissue engineering.

Xue Zhang - One of the best experts on this subject based on the ideXlab platform.

  • preparation and mechanical property of a novel 3d porous magnesium scaffold for bone tissue engineering
    Materials Science and Engineering: C, 2014
    Co-Authors: Xue Zhang, Xudong Sun
    Abstract:

    Porous magnesium has been recently recognized as a Biodegradable Metal for bone substitute applications. A novel porous Mg scaffold with three-dimensional (3D) interconnected pores and with a porosity of 33-54% was produced by the fiber deposition hot pressing (FDHP) technology. The microstructure and morphologies of the porous Mg scaffold were characterized by scanning electron microscopy (SEM), and the effects of porosities on the microstructure and mechanical properties of the porous Mg were investigated. Experimental results indicate that the measured Young's modulus and compressive strength of the Mg scaffold are ranged in 0.10-0.37 GPa, and 11.1-30.3 MPa, respectively, which are fairly comparable to those of cancellous bone. Such a porous Mg scaffold having a 3D interconnected network structure has the potential to be used in bone tissue engineering.

  • preparation and characterizations of bioglass ceramic cement ca p coating on pure magnesium for biomedical applications
    ACS Applied Materials & Interfaces, 2014
    Co-Authors: Xue Zhang, Xudong Sun
    Abstract:

    Magnesium has been recently recognized as a Biodegradable Metal for bone substitute applications. In order to improve the biocompatibility and osteointegration of pure Mg, two kinds of coatings, i.e., the Ca–P coating and bioglass ceramic cement (BGCC)/Ca–P coating, were prepared on the pure Mg ribbons in the present work. The Ca–P coating was obtained by aqueous solution method. Subsequently, Ca–P coated Mg was immersed into the BGCC slurry, which was prepared by the mix of SiO2–CaO–P2O5 bioglass ceramic (BGC) powders and phosphate liquid with a liquid-to-solid ratio (L/S) of 1.6, to obtain BGCC/Ca–P coating by a dipping–pulling method. The microstructures, morphologies, and compositions of these coatings have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). The effect of these coatings on the mineralization activity of pure Mg has been investigated. The results indicated that both the Ca–P coating and BGCC/Ca–P coating could ...