1
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Forkmann C, Pritsch M, Baumann-Zumstein P, Lootz D, Joner M. In vivo chronic scaffolding force of a resorbable magnesium scaffold. J Biomech 2024; 164:111988. [PMID: 38364489 DOI: 10.1016/j.jbiomech.2024.111988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 01/31/2024] [Accepted: 02/05/2024] [Indexed: 02/18/2024]
Abstract
The aim of this study is to qualitatively characterize the in vivo chronic scaffolding force of the Magmaris® Resorbable Magnesium Scaffold (RMS). This important parameter of scaffolds must be balanced between sufficient radial support during the healing period of the vessel and avoidance of long-term vessel caging. A finite element model was established using preclinical animal data and used to predict the device diameter and scaffolding force up to 90 days after implantation. To account for scaffold resorption, it included backbone degradation as well as formation of discontinuities as observed in vivo. The predictions of the model regarding acute recoil and chronic development of the device diameter were in good agreement with the preclinical data, supporting the validity of the model. It was found that after 28 and 90 days, the Magmaris® RMS retained 90 % and 47 % of its initial scaffolding force, respectively. The reduction in scaffolding force was mainly driven by discontinuities in the meandering segments. Finite element analysis combined with preclinical data is a reliable method to characterize the chronic scaffolding force.
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Affiliation(s)
| | | | | | - Daniel Lootz
- Biotronik AG, Ackerstraße 6, 8180 Bülach, Switzerland.
| | - Michael Joner
- German Heart Center Munich, Lazarettstraße 36, 80636 München, Germany.
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2
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Menze R, Hesse B, Kusmierczuk M, Chen D, Weitkamp T, Bettink S, Scheller B. Synchrotron microtomography reveals insights into the degradation kinetics of bio-degradable coronary magnesium scaffolds. Bioact Mater 2024; 32:1-11. [PMID: 37771679 PMCID: PMC10522944 DOI: 10.1016/j.bioactmat.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/18/2023] [Accepted: 09/12/2023] [Indexed: 09/30/2023] Open
Abstract
Bioresorbable magnesium scaffolds are a promising future treatment option for coronary artery stenosis, especially for young adults. Due to the degradation of these scaffolds (<1 year), long-term device-related clinical events could be reduced compared to treatments with conventional drug eluting stents. First clinical trials indicate a return of vasomotion after one year, which may be associated with improved long-term clinical outcomes. However, even after decades of development, the degradation process, ideal degradation time and biological response in vivo are still not fully understood. The present study investigates the in vivo degradation of magnesium scaffolds in the coronary arteries of pigs influenced by different strut thicknesses and the presence of antiproliferative drugs. Due to high 3D image contrast of synchrotron-based micro-CT with phase contrast (SR-μCT), a qualitative and quantitative evaluation of the degradation morphology of magnesium scaffolds was obtained. For the segmentation of the μCT images a convolutional network architecture (U-net) was exploited, demonstrating the huge potential of merging high resolution SR-μCT with deep learning (DL) supported data analysis. In total, 30 scaffolds, made of the rare earth alloy Resoloy®, with different strut designs were implanted into the coronary arteries of 10 domestic pigs for 28 days using drug-coated or uncoated angioplasty balloons for post-dilatation. The degradation morphology was analyzed using scanning electron microscopy, energy dispersive x-ray spectroscopy and SR-μCT. The data from these methods were then related to data from angiography, optical coherence tomography and histology. A thinner strut size (95 vs. 130 μm) and the presence of paclitaxel indicated a slower degradation rate at 28 d in vivo, which positively influences the late lumen loss (0.5 and 0.6 mm vs. 1.0 and 1.1 mm) and recoil values (0 and 1.7% vs. 6.1 and 22%).
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Affiliation(s)
- Roman Menze
- MeKo Manufacturing e.K., Im Kirchenfelde 12-14, 31157, Sarstedt, Germany
| | - Bernhard Hesse
- Xploraytion GmbH, Bismarckstr. 10-12, 10625, Berlin, Germany
| | | | - Duote Chen
- Xploraytion GmbH, Bismarckstr. 10-12, 10625, Berlin, Germany
| | - Timm Weitkamp
- Synchrotron SOLEIL, L'Orme des Merisiers, Départementale 128, 91190, Saint-Aubin, France
| | | | - Bruno Scheller
- Universität des Saarlandes, Campus Homburg, 66421, Homburg, Germany
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3
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Liu D, Yang K, Chen S. Development and Future Trends of Protective Strategies for Magnesium Alloy Vascular Stents. MATERIALS (BASEL, SWITZERLAND) 2023; 17:68. [PMID: 38203922 PMCID: PMC10779993 DOI: 10.3390/ma17010068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/09/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024]
Abstract
Magnesium alloy stents have been extensively studied in the field of biodegradable metal stents due to their exceptional biocompatibility, biodegradability and excellent biomechanical properties. Nevertheless, the specific in vivo service environment causes magnesium alloy stents to degrade rapidly and fail to provide sufficient support for a certain time. Compared to previous reviews, this paper focuses on presenting an overview of the development history, the key issues, mechanistic analysis, traditional protection strategies and new directions and protection strategies for magnesium alloy stents. Alloying, optimizing stent design and preparing coatings have improved the corrosion resistance of magnesium alloy stents. Based on the corrosion mechanism of magnesium alloy stents, as well as their deformation during use and environmental characteristics, we present some novel strategies aimed at reducing the degradation rate of magnesium alloys and enhancing the comprehensive performance of magnesium alloy stents. These strategies include adapting coatings for the deformation of the stents, preparing rapid endothelialization coatings to enhance the service environment of the stents, and constructing coatings with self-healing functions. It is hoped that this review can help readers understand the development of magnesium alloy cardiovascular stents and solve the problems related to magnesium alloy stents in clinical applications at the early implantation stage.
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Affiliation(s)
- Dexiao Liu
- Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
| | - Ke Yang
- Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Shanshan Chen
- Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
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4
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Dou Z, Chen S, Wang J, Xia L, Maitz MF, Tu Q, Zhang W, Yang Z, Huang N. A "built-up" composite film with synergistic functionalities on Mg-2Zn-1Mn bioresorbable stents improves corrosion control effects and biocompatibility. Bioact Mater 2023; 25:223-238. [PMID: 36817823 PMCID: PMC9929524 DOI: 10.1016/j.bioactmat.2023.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/04/2023] [Accepted: 02/04/2023] [Indexed: 02/11/2023] Open
Abstract
Control of premature corrosion of magnesium (Mg) alloy bioresorbable stents (BRS) is frequently achieved by the addition of rare earth elements. However, limited long-term experience with these elements causes concerns for clinical application and alternative methods of corrosion control are sought after. Herein, we report a "built-up" composite film consisting of a bottom layer of MgF2 conversion coating, a sandwich layer of a poly (1, 3-trimethylene carbonate) (PTMC) and 3-aminopropyl triethoxysilane (APTES) co-spray coating (PA) and on top a layer of poly (lactic-co-glycolic acid) (PLGA) ultrasonic spray coating to decorate the rare earth element-free Mg-2Zn-1Mn (ZM21) BRS for tailoring both corrosion resistance and biological functions. The developed "built-up" composite film shows synergistic functionalities, allowing the compression and expansion of the coated ZM21 BRS on an angioplasty balloon without cracking or peeling. Of special importance is that the synergistic corrosion control effects of the "built-up" composite film allow for maintaining the mechanical integrity of stents for up to 3 months, where complete biodegradation and no foreign matter residue were observed about half a year after implantation in rabbit iliac arteries. Moreover, the functionalized ZM21 BRS accomplished re-endothelialization within one month.
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Affiliation(s)
- Zhenglong Dou
- Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Shuiling Chen
- Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Jiacheng Wang
- Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Li Xia
- Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Manfred F. Maitz
- Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
- Max Bergmann Center of Biomaterials Dresden, Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, 01069, Dresden, Germany
| | - Qiufen Tu
- Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Wentai Zhang
- Affiliated Dongguan Hospital, Southern Medical University, Dongguan, Guangdong, 523059, China
| | - Zhilu Yang
- Affiliated Dongguan Hospital, Southern Medical University, Dongguan, Guangdong, 523059, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Guangzhou, Guangdong, 510080, China
- Department of Cardiology, Third People's Hospital of Chengdu Affiliated to Southwest Jiaotong University, Chengdu, 610031, China
- Corresponding author. Affiliated Dongguan Hospital, Southern Medical University, Dongguan, Guangdong, 523059, China.
| | - Nan Huang
- Key Lab of Advanced Technology of Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
- Affiliated Dongguan Hospital, Southern Medical University, Dongguan, Guangdong, 523059, China
- Corresponding author. Affiliated Dongguan Hospital, Southern Medical University, Dongguan, Guangdong, 523059, China.
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5
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Zhang Y, Chen S, Zhang H, Ma C, Du T, Qiao A. Model construction and numerical simulation of arterial remodeling after stent implantation with variations of cell concentration. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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6
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Shi L, Chen S, Zheng F, Mingming L, Yang H, Zhang B. Corrosion resistance evaluation of biodegradable magnesium alloy vascular stents optimized by mechanical adapted polymer coating strategy. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.130664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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7
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Zhang H, Du T, Chen S, Liu Y, Yang Y, Hou Q, Qiao A. Finite Element Analysis of the Non-Uniform Degradation of Biodegradable Vascular Stents. J Funct Biomater 2022; 13:jfb13030152. [PMID: 36135587 PMCID: PMC9501085 DOI: 10.3390/jfb13030152] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Most of the studies on the finite element analysis (FEA) of biodegradable vascular stents (BVSs) during the degradation process have limited the accuracy of the simulation results due to the application of the uniform degradation model. This paper aims to establish an FEA model for the non-uniform degradation of BVSs by considering factors such as the dynamic changes of the corrosion properties and material properties of the element, as well as the pitting corrosion and stress corrosion. The results revealed that adjusting the corrosion rate according to the number of exposed surfaces of the element and reducing the stress threshold according to the corrosion status accelerates the degradation time of BVSs by 26% and 25%, respectively, compared with the uniform degradation model. The addition of the pitting model reduces the service life of the BVSs by up to 12%. The effective support of the stent to the vessel could reach at least 60% of the treatment effect before the vessel collapsed. These data indicate that the proposed non-uniform degradation model of BVSs with multiple factors produces different phenomena compared with the commonly used models and make the numerical simulation results more consistent with the real degradation scenario.
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8
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Erişen DE, Zhang Y, Zhang B, Yang K, Chen S, Wang X. Biosafety and biodegradation studies of AZ31B magnesium alloy carotid artery stent in vitro and in vivo. J Biomed Mater Res B Appl Biomater 2021; 110:239-248. [PMID: 34236133 DOI: 10.1002/jbm.b.34907] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 04/28/2021] [Accepted: 06/13/2021] [Indexed: 12/16/2022]
Abstract
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.
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Affiliation(s)
- Deniz Eren Erişen
- School of Materials Science and Engineering, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, China.,Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, Liaoning, 110016, China
| | - Yuqi Zhang
- Department of Neurology, The PLA General Hospital, Beijing, China
| | - Bingchun Zhang
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, Liaoning, 110016, China
| | - Ke Yang
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, Liaoning, 110016, China
| | - Shanshan Chen
- Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, Liaoning, 110016, China
| | - Xiaolin Wang
- Department of Neurology, The PLA General Hospital, Beijing, China
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9
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10
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Duenas J, Garcia J, Castro F, Munoz J, Sierra-Pallares J. Estimation of degradation velocity of biocompatible damaged stents due to blood flow. IEEE Trans Biomed Eng 2021; 68:3525-3533. [PMID: 33909557 DOI: 10.1109/tbme.2021.3076242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Bioresorbable materials represent a promising technology for the treatment of coronary disease. Among the different materials employed, magnesium stents display favourable mechanical properties. One of the main uncertainties regarding use is their behaviour when deployed on coronary bifurcations, especially when their retardant coating has been damaged during the implantation process. This paper analyses the temporal evolution of the degradation of a damaged magnesium stent inserted into a coronary bifurcation. METHODS The rate of erosion-corrosion and the effect of the flow configuration on the mass transfer coefficient were estimated on the basis of previous experimental studies and numerical simulations. This coefficient has been employed to reproduce the conditions that can appear in real stent configurations, and computational fluid dynamics simulations were performed. RESULTS The diffusion coefficient for this particular case has been calculated from the mass transfer coefficient and the Sherwood number. The results of the simulation show how the presence of the inner artery wall has a positive effect, preventing a premature degradation of the stent, and how the distal strut is protected by the presence of the proximal struts. CONCLUSIONS This study demonstrates the usefulness of the proposed methodology to evaluate the temporal evolution of the degradation of struts made of magnesium alloys. In addition, this methodology can be applied to a study of different materials and geometric configurations. SIGNIFICANCE The proposed technique can contribute to expanding existing knowledge concerning bioresorbable stent flow-corrosion, thus improving their design and implantation.
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11
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Wang R, Yuan Z, Li Q, Yang B, Zuo H. Damage evolution of biodegradable magnesium alloy stent based on configurational forces. J Biomech 2021; 122:110443. [PMID: 33933858 DOI: 10.1016/j.jbiomech.2021.110443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 03/29/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022]
Abstract
Magnesium alloy has attracted most of the recent attention as a candidate for stent material due to their biocompatible and biodegradable nature. However, their corrosion behavior in the human body is still a major issue in research today. In this paper, a strategy to simulate damage evolution in biodegradable magnesium alloy stent is given by introducing a configurational damage model. In the framework of continuum thermodynamics, one can characterize the development and evolution of local damage of materials by establishing internal variables in phenomenological method. We believe that corrosion can damage alloy in two different ways: surface corrosion and stress corrosion. Surface corrosion is described using uniform damage, when the structure is exposed in a corrosion environment; Configurational force is used to describe stress corrosion when the structure is exposed in a stimulating environment. We then select global damage and radial resistance force to perform the changes of macroscopic mechanical properties during stent degradation. Finally, the well performance of the proposed model is demonstrated through several numerical examples. This model has the potential to assist stent design and development in the future.
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Affiliation(s)
- Rong Wang
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China; School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Zhongbo Yuan
- State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qun Li
- State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Bo Yang
- Department of Thoracic Surgery, Tianjin First Central Hospital, Tianjin Medical University, Tianjin 300192, China
| | - Hong Zuo
- State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, China.
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12
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Bian D, Zhou X, Liu J, Li W, Shen D, Zheng Y, Gu W, Jiang J, Li M, Chu X, Ma L, Wang X, Zhang Y, Leeflang S, Zhou J. Degradation behaviors and in-vivo biocompatibility of a rare earth- and aluminum-free magnesium-based stent. Acta Biomater 2021; 124:382-397. [PMID: 33508506 DOI: 10.1016/j.actbio.2021.01.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/14/2021] [Accepted: 01/19/2021] [Indexed: 12/14/2022]
Abstract
Biodegradable stents can provide scaffolding and anti-restenosis benefits in the short term and then gradually disappear over time to free the vessel, among which the Mg-based biodegradable metal stents have been prosperously developed. In the present study, a Mg-8.5Li (wt.%) alloy (RE- and Al-free) with high ductility (> 40%) was processed into mini-tubes, and further fabricated into finished stent through laser cutting and electropolishing. In-vitro degradation test was performed to evaluate the durability of this stent before and after balloon dilation. The influence of plastic deformation and residual stress (derived from the dilation process) on the degradation was checked with the assistance of finite element analysis. In addition, in-vivo degradation behaviors and biocompatibility of the stent were evaluated by performing implantation in iliac artery of minipigs. The balloon dilation process did not lead to deteriorated degradation, and this stent exhibited a decent degradation rate (0.15 mm/y) in vitro, but divergent result (> 0.6 mm/y) was found in vivo. The stent was almost completely degraded in 3 months, revealing an insufficient scaffolding time. Meanwhile, it did not induce possible thrombus, and it was tolerable by surrounding tissues in pigs. Besides, endothelial coverage in 1 month was achieved even under the severe degradation condition. In the end, the feasibility of this stent for treatment of benign vascular stenosis was generally discussed, and perspectives on future improvement of Mg-Li-based stents were proposed.
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Affiliation(s)
- Dong Bian
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Xiaochen Zhou
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Jianing Liu
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Wenting Li
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Danni Shen
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Yufeng Zheng
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China; Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, 100871, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
| | - Wenda Gu
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Jingjun Jiang
- Department of Vascular Surgery, Peking University People's Hospital, Beijing, 100044, China
| | - Mei Li
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Xiao Chu
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Limin Ma
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Xiaolan Wang
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Yu Zhang
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Sander Leeflang
- Department of Biomechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, Netherlands
| | - Jie Zhou
- Department of Biomechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, Netherlands
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13
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Development of a micro-scale method to assess the effect of corrosion on the mechanical properties of a biodegradable Fe-316L stent material. J Mech Behav Biomed Mater 2020; 114:104173. [PMID: 33160911 DOI: 10.1016/j.jmbbm.2020.104173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/04/2020] [Accepted: 10/23/2020] [Indexed: 11/22/2022]
Abstract
The application of biodegradable materials to stent design has the potential to transform coronary artery disease treatment. It is critical that biodegradable stents have sustained strength during degradation and vessel healing to prevent re-occlusion. Proper assessment of the impact of corrosion on the mechanical behaviour of potential biomaterials is important. Investigations within literature frequently implement simplified testing conditions to understand this behaviour and fail to consider size effects associated with strut thickness, or the increase in corrosion due to blood flow, both of which can impact material properties. A protocol was developed that utilizes micro-scale specimens, in conjunction with dynamic degradation, to assess the effect of corrosion on the mechanical properties of a novel Fe-316L material. Dynamic degradation led to increased specimen corrosion, resulting in a greater reduction in strength after 48 h of degradation in comparison to samples statically corroded. It was found that thicker micro-tensile samples (h > 200 μm) had a greater loss of strength in comparison to its thinner counterpart (h < 200 μm), due to increased corrosion of the thicker samples (203 MPa versus 260 MPa after 48 h, p = 0.0017). This investigation emphasizes the necessity of implementing physiologically relevant testing conditions, including dynamic corrosion and stent strut thickness, when evaluating potential biomaterials for biodegradable stent application.
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14
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Ni X, Zhang Y, Pan C. The degradable performance of bile-duct stent based on a continuum damage model: A finite element analysis. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3370. [PMID: 32449607 DOI: 10.1002/cnm.3370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 02/28/2020] [Accepted: 05/16/2020] [Indexed: 06/11/2023]
Abstract
Biomedical magnesium alloy stents have become a hot bed of research focus in interventional therapy for nonvascular diseases. In this study, a numerical model for a balloon-expandable bile duct stent made of magnesium alloy with laser sculpture is developed to predict the effects of the degradation of the stent on the biomechanical behavior in the stent-bile duct coupling system. Based on a continuum damage model, the degradable model of the stent is built to understand its performance in an idealized bile duct as it is subject to corrosion over time. The degradation model developed in this study addresses the uniform corrosion and pitting corrosion. By means of the secondary development function of commercial numerical software ANSYS, the finite element analysis procedures were written to control the degradation process based on the technology of element "birth and death," and it is shown how the three-dimensional model and approach give the possibility of analyzing for the degradation mechanism of a magnesium alloy stent in the bile duct or other nonvascular cavities.
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Affiliation(s)
- Xiaoyu Ni
- School of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, China
| | - Yanhong Zhang
- School of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, China
| | - Changwang Pan
- Jiangsu Key Laboratory for Design and Manufacture of Micro/Nano Biomedical Instruments, Micro-Tech (Nanjing) Co., Ltd., Nanjing, China
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15
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Campos Becerra LH, Hernández Rodríguez MAL, Esquivel Solís H, Lesso Arroyo R, Torres Castro A. Bio-inspired biomaterial Mg-Zn-Ca: a review of the main mechanical and biological properties of Mg-based alloys. Biomed Phys Eng Express 2020; 6:042001. [PMID: 33444260 DOI: 10.1088/2057-1976/ab9426] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The toxicity of alloying elements in magnesium alloys used for biomedical purposes is an interesting and innovative subject, due to the great technological advances that would result from their application in medical devices (MDs) in traumatology. Recently promising results have been published regarding the rates of degradation and mechanical integrity that can support Mg alloys; this has led to an interest in understanding the toxicological features of these emerging biomaterials. The growing interest of different segments of the MD market has increased the determination of different research groups to clarify the behavior of alloying elements in vivo. This review covers the influence of the alloying elements on the body, the toxicity of the elements in Mg-Zn-Ca, as well as the mechanical properties, degradation, processes of obtaining the alloy, medical approaches and future perspectives on the use of the Mg in the manufacture of MDs for various medical applications.
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Affiliation(s)
- Luis Humberto Campos Becerra
- Facultad de Ingeniería Mecánica y Eléctrica., Biomateriales. Universidad Autónoma de Nuevo León (UANL), Pedro de Alba S/N, Ciudad Universitaria, San Nicolás de los Garza, México
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Song K, Bi Y, Zhao H, Wu T, Xu F, Zhao G. Structural optimization and finite element analysis of poly‐
l
‐lactide acid coronary stent with improved radial strength and acute recoil rate. J Biomed Mater Res B Appl Biomater 2020; 108:2754-2764. [DOI: 10.1002/jbm.b.34605] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/02/2020] [Accepted: 03/01/2020] [Indexed: 02/02/2023]
Affiliation(s)
- Kai Song
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
| | - Yuying Bi
- Dongguan TT Medical Inc. Guangdong China
- Biomedical Engineering and Biotechnology University of Massachusetts Lowell Massachusetts
| | - Haibin Zhao
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
- Shenzhen Research Institute of Shandong University, Shenzhen Guangdong China
| | - Tim Wu
- Dongguan TT Medical Inc. Guangdong China
- Biomedical Engineering and Biotechnology University of Massachusetts Lowell Massachusetts
| | - Feng Xu
- Department of Emergency Medicine, Qilu Hospital, Shandong University Jinan China
| | - Guoqun Zhao
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
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Chen C, Chen J, Wu W, Shi Y, Jin L, Petrini L, Shen L, Yuan G, Ding W, Ge J, Edelman ER, Migliavacca F. In vivo and in vitro evaluation of a biodegradable magnesium vascular stent designed by shape optimization strategy. Biomaterials 2019; 221:119414. [PMID: 31419654 PMCID: PMC6732791 DOI: 10.1016/j.biomaterials.2019.119414] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 07/30/2019] [Accepted: 08/03/2019] [Indexed: 01/25/2023]
Abstract
The performance of biodegradable magnesium alloy stents (BMgS) requires special attention to non-uniform residual stress distribution and stress concentration, which can accelerate localized degradation after implantation. We now report on a novel concept in stent shape optimization using a finite element method (FEM) toolkit. A Mg-Nd-Zn-Zr alloy with uniform degradation behavior served as the basis of our BMgS. Comprehensive in vitro evaluations drove stent optimization, based on observed crimping and balloon inflation performance, measurement of radial strength, and stress condition validation via microarea-XRD. Moreover, a Rapamycin-eluting polymer coating was sprayed on the prototypical BMgS to improve the corrosion resistance and release anti-hyperplasia drugs. In vivo evaluation of the optimized coated BMgS was conducted in the iliac artery of New Zealand white rabbit with quantitative coronary angiography (QCA), optical coherence tomography (OCT) and micro-CT observation at 1, 3, 5-month follow-ups. Neither thrombus or early restenosis was observed, and the coated BMgS supported the vessel effectively prior to degradation and allowed for arterial healing thereafter. The proposed shape optimization framework based on FEM provides an novel concept in stent design and in-depth understanding of how deformation history affects the biomechanical performance of BMgS. Computational analysis tools can indeed promote the development of biodegradable magnesium stents.
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Affiliation(s)
- Chenxin Chen
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China; Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy
| | - Jiahui Chen
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Wei Wu
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy; Department of Mechanical Engineering, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249-0669, USA
| | - Yongjuan Shi
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Liang Jin
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Lorenza Petrini
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy
| | - Li Shen
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Guangyin Yuan
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
| | - Wenjiang Ding
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Junbo Ge
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Elazer R Edelman
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, 20133, Italy.
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18
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Chen C, Xiong Y, Jiang W, Wang Y, Wang Z, Chen Y. Experimental and Numerical Simulation of Biodegradable Stents with Different Strut Geometries. Cardiovasc Eng Technol 2019; 11:36-46. [DOI: 10.1007/s13239-019-00433-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/09/2019] [Indexed: 10/25/2022]
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19
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Riaz U, Shabib I, Haider W. The current trends of Mg alloys in biomedical applications-A review. J Biomed Mater Res B Appl Biomater 2018; 107:1970-1996. [PMID: 30536973 DOI: 10.1002/jbm.b.34290] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 11/10/2018] [Accepted: 11/15/2018] [Indexed: 01/25/2023]
Abstract
Magnesium (Mg) has emerged as an ideal alternative to the permanent implant materials owing to its enhanced properties such as biodegradation, better mechanical strengths than polymeric biodegradable materials and biocompatibility. It has been under investigation as an implant material both in cardiovascular and orthopedic applications. The use of Mg as an implant material reduces the risk of long-term incompatible interaction of implant with tissues and eliminates the second surgical procedure to remove the implant, thus minimizes the complications. The hurdle in the extensive use of Mg implants is its fast degradation rate, which consequently reduces the mechanical strength to support the implant site. Alloy development, surface treatment, and design modification of implants are the routes that can lead to the improved corrosion resistance of Mg implants and extensive research is going on in all three directions. In this review, the recent trends in the alloying and surface treatment of Mg have been discussed in detail. Additionally, the recent progress in the use of computational models to analyze Mg bioimplants has been given special consideration. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1970-1996, 2019.
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Affiliation(s)
- Usman Riaz
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, Michigan, 48859
| | - Ishraq Shabib
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, Michigan, 48859.,Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan, 48859
| | - Waseem Haider
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, Michigan, 48859.,Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan, 48859
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20
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Chen C, Tan J, Wu W, Petrini L, Zhang L, Shi Y, Cattarinuzzi E, Pei J, Huang H, Ding W, Yuan G, Migliavacca F. Modeling and Experimental Studies of Coating Delamination of Biodegradable Magnesium Alloy Cardiovascular Stents. ACS Biomater Sci Eng 2018; 4:3864-3873. [DOI: 10.1021/acsbiomaterials.8b00700] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Chenxin Chen
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China, 200240
| | - Jinyun Tan
- Department of Vascular Surgery, Huashan Hospital of Fudan University, No. 12 Mid-Wulumuqi Road, Shanghai 200040, China
| | - Wei Wu
- Department of Mechanical Engineering, The University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0669, United States
| | | | - Lei Zhang
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China, 200240
| | - Yongjuan Shi
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China, 200240
| | | | - Jia Pei
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China, 200240
| | - Hua Huang
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China, 200240
| | - Wenjiang Ding
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China, 200240
| | - Guangyin Yuan
- National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China, 200240
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21
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Riaz U, Rakesh L, Shabib I, Haider W. Effect of dissolution of magnesium alloy AZ31 on the rheological properties of Phosphate Buffer Saline. J Mech Behav Biomed Mater 2018; 85:201-208. [PMID: 29908488 DOI: 10.1016/j.jmbbm.2018.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/19/2018] [Accepted: 06/01/2018] [Indexed: 01/29/2023]
Abstract
The issue of long-term incompatible interactions associated with the permanent implants can be eliminated by using various biodegradable metal implants. The recent research is focusing on the use of degradable stents to restore most of the hindrances of capillaries, and coronary arteries by supplying instant blood flow with constant mechanical and structural support. However, internal endothelialization and infection due to the corrosion of implanted stents are not easy to diagnose in the long run. In the recent past, magnesium (Mg) has been widely investigated for the cardiovascular stent applications. Here we made an attempt to understand the biodegradation process of Mg alloy stent by studying the degradation of Mg alloy AZ31 (3 wt% Aluminum, 1 wt% Zn) powder at various time-intervals in simulated blood fluid using the Rheological methods. The degradability of the Mg stent in the arteries affects the stress-strain properties of blood plasma and the subsequent flow conditions. Blood and plasma viscosities alter due to the degradation of Mg resulting from the stress-strain experienced in the blood vessels, in which the stent is inserted. Here our objective was to explore the influence of Mg degradation on the blood plasma viscosity by studying the viscoelastic properties. In this work, the effect of dissolution of Mg alloy AZ31 on the rheological properties of Phosphate Buffer Saline (PBS) at various time intervals have been investigated. The viscosity of the PBS-AZ31 solution increased with the dissolution of both slurries and percolated clear solution. The only exception was day-7 of the percolated clear solution, where viscosity was decreased showing a reduction in viscosity at initial stages of dissolution. The frequency sweep showed the tendency of the PBS-AZ31 gelation up to 100 rad/s frequency.
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Affiliation(s)
- Usman Riaz
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Leela Rakesh
- Department of Mathematics, Center for Applied Mathematics & Polymer Fluid Dynamics, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Ishraq Shabib
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI 48859, USA; Science of Advanced Materials, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Waseem Haider
- School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI 48859, USA; Science of Advanced Materials, Central Michigan University, Mount Pleasant, MI 48859, USA.
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22
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Gao Y, Wang L, Gu X, Chu Z, Guo M, Fan Y. A quantitative study on magnesium alloy stent biodegradation. J Biomech 2018; 74:98-105. [DOI: 10.1016/j.jbiomech.2018.04.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 03/14/2018] [Accepted: 04/14/2018] [Indexed: 11/26/2022]
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23
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A strain-mediated corrosion model for bioabsorbable metallic stents. Acta Biomater 2017; 55:505-517. [PMID: 28433790 DOI: 10.1016/j.actbio.2017.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/28/2017] [Accepted: 04/18/2017] [Indexed: 11/24/2022]
Abstract
This paper presents a strain-mediated phenomenological corrosion model, based on the discrete finite element modelling method which was developed for use with the ANSYS Implicit finite element code. The corrosion model was calibrated from experimental data and used to simulate the corrosion performance of a WE43 magnesium alloy stent. The model was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile. The non-linear plastic strain model, extrapolated from the experimental data, was also found to adequately capture the corrosion-induced reduction in the radial stiffness of the stent over time. The model developed will help direct future design efforts towards the minimisation of plastic strain during device manufacture, deployment and in-service, in order to reduce corrosion rates and prolong the mechanical integrity of magnesium devices. STATEMENT OF SIGNIFICANCE The need for corrosion models that explore the interaction of strain with corrosion damage has been recognised as one of the current challenges in degradable material modelling (Gastaldi et al., 2011). A finite element based plastic strain-mediated phenomenological corrosion model was developed in this work and was calibrated based on the results of the corrosion experiments. It was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile and the corrosion-induced reduction in the radial stiffness of the stent over time. To the author's knowledge, the results presented here represent the first experimental calibration of a plastic strain-mediated corrosion model of a corroding magnesium stent.
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Boland EL, Grogan JA, McHugh PE. Computational Modeling of the Mechanical Performance of a Magnesium Stent Undergoing Uniform and Pitting Corrosion in a Remodeling Artery. J Med Device 2017. [DOI: 10.1115/1.4035895] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Coronary stents made from degradable biomaterials such as magnesium alloy are an emerging technology in the treatment of coronary artery disease. Biodegradable stents provide mechanical support to the artery during the initial scaffolding period after which the artery will have remodeled. The subsequent resorption of the stent biomaterial by the body has potential to reduce the risk associated with long-term placement of these devices, such as in-stent restenosis, late stent thrombosis, and fatigue fracture. Computational modeling such as finite-element analysis has proven to be an extremely useful tool in the continued design and development of these medical devices. What is lacking in computational modeling literature is the representation of the active response of the arterial tissue in the weeks and months following stent implantation, i.e., neointimal remodeling. The phenomenon of neointimal remodeling is particularly interesting and significant in the case of biodegradable stents, when both stent degradation and neointimal remodeling can occur simultaneously, presenting the possibility of a mechanical interaction and transfer of load between the degrading stent and the remodeling artery. In this paper, a computational modeling framework is developed that combines magnesium alloy degradation and neointimal remodeling, which is capable of simulating both uniform (best case) and localized pitting (realistic) stent corrosion in a remodeling artery. The framework is used to evaluate the effects of the neointima on the mechanics of the stent, when the stent is undergoing uniform or pitting corrosion, and to assess the effects of the neointimal formation rate relative to the overall stent degradation rate (for both uniform and pitting conditions).
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Affiliation(s)
- Enda L. Boland
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway H91 HX31, Ireland e-mail:
| | - James A. Grogan
- Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway H91 HX31, Ireland
| | - Peter E. McHugh
- Professor Biomechanics Research Centre (BMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway H91 HX31, Ireland e-mail:
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25
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Expandable Mg-based Helical Stent Assessment using Static, Dynamic, and Porcine Ex Vivo Models. Sci Rep 2017; 7:1173. [PMID: 28446750 PMCID: PMC5430820 DOI: 10.1038/s41598-017-01214-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/27/2017] [Indexed: 12/21/2022] Open
Abstract
A bioresorbable metallic helical stent was explored as a new device opportunity (magnesium scaffold), which can be absorbed by the body without leaving a trace and simultaneously allowing restoration of vasoreactivity with the potential for vessel remodeling. In this study, developed Mg-based helical stent was inserted and expanded in vessels with subsequent degradation in various environments including static, dynamic, and porcine ex vivo models. By assessing stent degradation in three different environments, we observed: (1) stress- and flow-induced degradation; (2) a high degradation rate in the dynamic reactor; (3) production of intermediate products (MgO/Mg(OH)2 and Ca/P) during degradation; and (4) intermediate micro-gas pocket formation in the neighboring tissue ex vivo model. Overall, the expandable Mg-based helical stent employed as a scaffold performed well, with expansion rate (>100%) in porcine ex vivo model.
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26
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Galvin E, Cummins C, Yoshihara S, Mac Donald BJ, Lally C. Plastic strains during stent deployment have a critical influence on the rate of corrosion in absorbable magnesium stents. Med Biol Eng Comput 2016; 55:1261-1275. [DOI: 10.1007/s11517-016-1584-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 10/05/2016] [Indexed: 10/20/2022]
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27
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A Computational Framework to Model Degradation of Biocorrodible Metal Stents Using an Implicit Finite Element Solver. Ann Biomed Eng 2015; 44:382-90. [DOI: 10.1007/s10439-015-1530-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 12/03/2015] [Indexed: 11/26/2022]
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A Review of Material Degradation Modelling for the Analysis and Design of Bioabsorbable Stents. Ann Biomed Eng 2015; 44:341-56. [DOI: 10.1007/s10439-015-1413-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 07/30/2015] [Indexed: 12/20/2022]
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Yue Y, Wang L, Yang N, Huang J, Lei L, Ye H, Ren L, Yang S. Effectiveness of Biodegradable Magnesium Alloy Stents in Coronary Artery and Femoral Artery. J Interv Cardiol 2015. [DOI: 10.1111/joic.12217] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Yunan Yue
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
| | - Lili Wang
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
| | - Nuo Yang
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
| | - Jinglin Huang
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
| | - Licheng Lei
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
| | - Huiming Ye
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
| | - Lihui Ren
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
| | - Shuixiang Yang
- Cardiology Department; Peking University Ninth School of Clinical Medicine; Beijing China
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Iglesias C, Bodelón OG, Montoya R, Clemente C, Garcia-Alonso MC, Rubio JC, Escudero ML. Fracture bone healing and biodegradation of AZ31 implant in rats. ACTA ACUST UNITED AC 2015; 10:025008. [PMID: 25886380 DOI: 10.1088/1748-6041/10/2/025008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The ideal temporary implant should offer enough mechanical support to allow healing of the fracture and then biodegrade and be resorbed by metabolic mechanisms without causing any toxic effect. The aim of this research has been to simultaneously study in situ bone healing and the biodegradation of AZ31 Mg alloy as an osteosynthesis material. The in vivo study was carried out in AZ31 implants with and without Mg-fluoride coating inserted in un-fractured and fractured femurs of Wistar rats for long experimentation time, from 1 to 13 months, by means of computed tomography, histological and histomorphometric analysis. Tomography analysis showed the bone healing and biodegradation of AZ31 implants. The fracture is healed in 100% of the animals, and AZ31 maintains its mechanical integrity throughout the healing process. Biodegradation was monitored, quantifying the evolution of gas over time by 3D composition of tomography images. In all the studied groups, gas pockets disappear with time as a result of the diffusion process through soft tissues. Histomorphometric studies reveal that after 13 months the 46.32% of AZ31 alloy has been resorbed. The resorption of the coated and uncoated AZ31 implants inserted in fractured femurs after 1, 9 and 13 months does not have statistically significant differences. There is a balance between the biodegradation of AZ31 and bone healing which allows the use of AZ31 to be proposed as an osteosynthesis material.
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Affiliation(s)
- C Iglesias
- Department of Plastic Surgery, Hospital Universitario La Paz, Madrid, 28046, Spain
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31
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Wang J, Smith CE, Sankar J, Yun Y, Huang N. Absorbable magnesium-based stent: physiological factors to consider for in vitro degradation assessments. Regen Biomater 2015; 2:59-69. [PMID: 26816631 PMCID: PMC4669031 DOI: 10.1093/rb/rbu015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 09/30/2014] [Indexed: 12/15/2022] Open
Abstract
Absorbable metals have been widely tested in various in vitro settings using cells to evaluate their possible suitability as an implant material. However, there exists a gap between in vivo and in vitro test results for absorbable materials. A lot of traditional in vitro assessments for permanent materials are no longer applicable to absorbable metallic implants. A key step is to identify and test the relevant microenvironment and parameters in test systems, which should be adapted according to the specific application. New test methods are necessary to reduce the difference between in vivo and in vitro test results and provide more accurate information to better understand absorbable metallic implants. In this investigative review, we strive to summarize the latest test methods for characterizing absorbable magnesium-based stent for bioabsorption/biodegradation behavior in the mimicking vascular environments. Also, this article comprehensively discusses the direction of test standardization for absorbable stents to paint a more accurate picture of the in vivo condition around implants to determine the most important parameters and their dynamic interactions.
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Affiliation(s)
- Juan Wang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China and National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA
| | - Christopher E Smith
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China and National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA
| | - Jagannathan Sankar
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China and National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA
| | - Yeoheung Yun
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China and National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA
| | - Nan Huang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China and National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA
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32
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Finite element analyses for optimization design of biodegradable magnesium alloy stent. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 42:705-14. [DOI: 10.1016/j.msec.2014.05.078] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/07/2014] [Accepted: 05/13/2014] [Indexed: 11/23/2022]
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33
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Computational micromechanics of bioabsorbable magnesium stents. J Mech Behav Biomed Mater 2014; 34:93-105. [DOI: 10.1016/j.jmbbm.2014.01.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 01/10/2014] [Accepted: 01/13/2014] [Indexed: 11/22/2022]
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34
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Grogan J, Leen S, McHugh P. A physical corrosion model for bioabsorbable metal stents. Acta Biomater 2014; 10:2313-22. [PMID: 24412771 DOI: 10.1016/j.actbio.2013.12.059] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 12/06/2013] [Accepted: 12/31/2013] [Indexed: 01/17/2023]
Abstract
Absorbable metal stents (AMSs) are an emerging technology in the treatment of heart disease. Computational modelling of AMS performance will facilitate the development of this technology. In this study a physical corrosion model is developed for AMSs based on the finite element method and adaptive meshing. The model addresses a gap between currently available phenomenological corrosion models for AMSs and physical corrosion models that have been developed for more simple geometries than those of a stent. The model developed in this study captures the changing surface of a corroding three-dimensional AMS structure for the case of diffusion-controlled corrosion. Comparisons are made between model predictions and those of previously developed phenomenological corrosion models for AMSs in terms of predicted device geometry and mechanical performance during corrosion. Relationships between alloy solubility and diffusivity in the corrosion environment and device performance during corrosion are also investigated.
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