1
|
He S, Wei L, Wang G, Pugno NM, Chen Q, Li Z. In Silico Evaluation of In Vivo Degradation Kinetics of Poly(Lactic Acid) Vascular Stent Devices. J Funct Biomater 2024; 15:135. [PMID: 38786646 PMCID: PMC11122488 DOI: 10.3390/jfb15050135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/09/2024] [Accepted: 05/11/2024] [Indexed: 05/25/2024] Open
Abstract
Biodegradable vascular stents (BVS) are deemed as great potential alternatives for overcoming the inherent limitations of permanent metallic stents in the treatment of coronary artery diseases. The current study aimed to comprehensively compare the mechanical behaviors of four poly(lactic acid) (PLA) BVS designs with varying geometries via numerical methods and to clarify the optimal BVS selection. Four PLA BVS (i.e., Absorb, DESolve, Igaki-Tamai, and Fantom) were first constructed. A degradation model was refined by simply including the fatigue effect induced by pulsatile blood pressures, and an explicit solver was employed to simulate the crimping and degradation behaviors of the four PLA BVS. The degradation dynamics here were characterized by four indices. The results indicated that the stent designs affected crimping and degradation behaviors. Compared to the other three stents, the DESolve stent had the greatest radial stiffness in the crimping simulation and the best diameter maintenance ability despite its faster degradation; moreover, the stent was considered to perform better according to a pilot scoring system. The current work provides a theoretical method for studying and understanding the degradation dynamics of the PLA BVS, and it could be helpful for the design of next-generation BVS.
Collapse
Affiliation(s)
- Shicheng He
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Lingling Wei
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230601, China
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Nicola M. Pugno
- Laboratory for Bioinspired, Bionic, Nano, Meta Materials and Mechanics, University of Trento, Via Mesiano 77, 38123 Trento, Italy
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Qiang Chen
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Zhiyong Li
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia
- Faculty of Sports Science, Ningbo University, Ningbo 315211, China
| |
Collapse
|
2
|
He S, Liu W, Wei L, Chen Q, Li Z. A phenomenological model of pulsatile blood pressure-affected degradation of polylactic acid (PLA) vascular stent. Med Biol Eng Comput 2024; 62:1347-1359. [PMID: 38183527 DOI: 10.1007/s11517-023-02998-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 12/09/2023] [Indexed: 01/08/2024]
Abstract
The stent implantation may alter the post-operative patient's blood pressure, and bioresorbable vascular stents (BVS) as a candidate to treat vascular diseases, its degradation is affected by mechanical stress, thus, the altered pressure representing varying stress level will result in different degradation behaviors of the BVS. This paper first proposed a novel stress-regulated PLA degradation model that included swelling factor, and then the degradation evolutions of a PLA BVS within 180 days under normal and high blood pressures were simulated by finite element method, and more four degradation indexes were defined to study the effects of the two blood pressures on the degradation of the PLA BVS. The results showed that the high pressure weakly accelerated the degradation of the PLA BVS with respect to the normal pressure by examining the four indexes, e.g., the residual stent volumev r ( t ) decreased to 0.72 and 0.69, respectively for the normal and high pressures at day 180. The current finding provided a theoretical understanding of the PLA BVS degradation, and hinted that the PLA BVS may not need to be elaborately selected in clinical practices for treating hypertensive patients.
Collapse
Affiliation(s)
- Shicheng He
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, People's Republic of China
| | - Wanling Liu
- Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210023, People's Republic of China
| | - Lingling Wei
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230601, People's Republic of China
| | - Qiang Chen
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Zhiyong Li
- Biomechanics Laboratory, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD4001, Australia.
- Faculty of Sports Science, Ningbo University, Ningbo, 315211, People's Republic of China.
| |
Collapse
|
3
|
Jin K, Li H, Liang M, Li Y, Wang L, Fan Y. Relationship between mechanical load and surface erosion degradation of a shape memory elastomer poly(glycerol-dodecanoate) for soft tissue implant. Regen Biomater 2023; 10:rbad050. [PMID: 37250974 PMCID: PMC10219789 DOI: 10.1093/rb/rbad050] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/17/2023] [Accepted: 05/04/2023] [Indexed: 05/31/2023] Open
Abstract
Poly(glycerol-dodecanoate) (PGD) has aroused increasing attention in biomedical engineering for its degradability, shape memory and rubber-like mechanical properties, giving it potential to fabricate intelligent implants for soft tissues. Adjustable degradation is important for biodegradable implants and is affected by various factors. The mechanical load has been shown to play an important role in regulating polymer degradation in vivo. An in-depth investigation of PGD degradation under mechanical load is essential for adjusting its degradation behavior after implantation, further guiding to regulate degradation behavior of soft tissue implants made by PGD. In vitro degradation of PGD under different compressive and tensile load has proceeded in this study and describes the relationships by empirical equations. Based on the equations, a continuum damage model is designed to simulate surface erosion degradation of PGD under stress through finite element analysis, which provides a protocol for PGD implants with different geometric structures at varied mechanical conditions and provides solutions for predicting in vivo degradation processes, stress distribution during degradation and optimization of the loaded drug release.
Collapse
Affiliation(s)
- Kaixiang Jin
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Hanqin Li
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Mingkai Liang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Yuqi Li
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Lizhen Wang
- Correspondence address. Tel: +86 10 82339861, E-mail: (L.W.); Tel: +86 10 82339428, E-mail: (Y.F.)
| | - Yubo Fan
- Correspondence address. Tel: +86 10 82339861, E-mail: (L.W.); Tel: +86 10 82339428, E-mail: (Y.F.)
| |
Collapse
|
4
|
Kovacevic S, Ali W, Martínez-Pañeda E, LLorca J. Phase-field modeling of pitting and mechanically-assisted corrosion of Mg alloys for biomedical applications. Acta Biomater 2023; 164:641-658. [PMID: 37068554 DOI: 10.1016/j.actbio.2023.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 03/21/2023] [Accepted: 04/07/2023] [Indexed: 04/19/2023]
Abstract
A phase-field model is developed to simulate the corrosion of Mg alloys in body fluids. The model incorporates both Mg dissolution and the transport of Mg ions in solution, naturally predicting the transition from activation-controlled to diffusion-controlled bio-corrosion. In addition to uniform corrosion, the presented framework captures pitting corrosion and accounts for the synergistic effect of aggressive environments and mechanical loading in accelerating corrosion kinetics. The model applies to arbitrary 2D and 3D geometries with no special treatment for the evolution of the corrosion front, which is described using a diffuse interface approach. Experiments are conducted to validate the model and a good agreement is attained against in vitro measurements on Mg wires. The potential of the model to capture mechano-chemical effects during corrosion is demonstrated in case studies considering Mg wires in tension and bioabsorbable coronary Mg stents subjected to mechanical loading. The proposed methodology can be used to assess the in vitro and in vivo service life of Mg-based biomedical devices and optimize the design taking into account the effect of mechanical deformation on the corrosion rate. The model has the potential to advocate further development of Mg alloys as a biodegradable implant material for biomedical applications. STATEMENT OF SIGNIFICANCE: A physically-based model is developed to simulate the corrosion of bioabsorbable metals in environments that resemble biological fluids. The model captures pitting corrosion and incorporates the role of mechanical fields in enhancing the corrosion of bioabsorbable metals. Model predictions are validated against dedicated in vitro corrosion experiments on Mg wires. The potential of the model to capture mechano-chemical effects is demonstrated in representative examples. The simulations show that the presence of mechanical fields leads to the formation of cracks accelerating the failure of Mg wires, whereas pitting severely compromises the structural integrity of coronary Mg stents. This work extends phase-field modeling to bioengineering and provides a mechanistic tool for assessing the service life of bioabsorbable metallic biomedical devices.
Collapse
Affiliation(s)
- Sasa Kovacevic
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK.
| | - Wahaaj Ali
- IMDEA Materials Institute, C/Eric Kandel 2, Getafe 28906, Madrid, Spain; Department of Material Science and Engineering, Universidad Carlos III de Madrid, Leganes 28911, Madrid, Spain
| | - Emilio Martínez-Pañeda
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK.
| | - Javier LLorca
- IMDEA Materials Institute, C/Eric Kandel 2, Getafe 28906, Madrid, Spain; Department of Materials Science, Polytechnic University of Madrid, E. T. S. de Ingenieros de Caminos, 28040 Madrid, Spain.
| |
Collapse
|
5
|
Liu Y, Du T, Qiao A, Mu Y, Yang H. Zinc-Based Biodegradable Materials for Orthopaedic Internal Fixation. J Funct Biomater 2022; 13:jfb13040164. [PMID: 36278633 PMCID: PMC9589944 DOI: 10.3390/jfb13040164] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/15/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022] Open
Abstract
Traditional inert materials used in internal fixation have caused many complications and generally require removal with secondary surgeries. Biodegradable materials, such as magnesium (Mg)-, iron (Fe)- and zinc (Zn)-based alloys, open up a new pathway to address those issues. During the last decades, Mg-based alloys have attracted much attention by researchers. However, the issues with an over-fast degradation rate and release of hydrogen still need to be overcome. Zn alloys have comparable mechanical properties with traditional metal materials, e.g., titanium (Ti), and have a moderate degradation rate, potentially serving as a good candidate for internal fixation materials, especially at load-bearing sites of the skeleton. Emerging Zn-based alloys and composites have been developed in recent years and in vitro and in vivo studies have been performed to explore their biodegradability, mechanical property, and biocompatibility in order to move towards the ultimate goal of clinical application in fracture fixation. This article seeks to offer a review of related research progress on Zn-based biodegradable materials, which may provide a useful reference for future studies on Zn-based biodegradable materials targeting applications in orthopedic internal fixation.
Collapse
Affiliation(s)
- Yang Liu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Tianming Du
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Aike Qiao
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Yongliang Mu
- School of Metallurgy, Northeastern University, Shenyang 110819, China
| | - Haisheng Yang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
- Correspondence: ; Tel.: +86-(010)-6739-6657
| |
Collapse
|
6
|
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.
Collapse
|
7
|
Graul LM, Liu S, Maitland DJ. Theoretical error of sectional method for estimation of shape memory polyurethane foam mass loss. J Colloid Interface Sci 2022; 625:237-247. [PMID: 35716618 DOI: 10.1016/j.jcis.2022.06.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 06/03/2022] [Accepted: 06/09/2022] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Measuring in vivo degradation for polymeric scaffolds is critical for analysis of biocompatibility. Traditionally, histology has been used to estimate mass loss in scaffolds, allowing for simultaneous evaluation of mass loss and the biologic response to the implant. Oxidatively degradable shape memory polyurethane (SMP) foams have been implemented in two vascular occlusion devices: peripheral embolization device (PED) and neurovascular embolization device (NED). This work explores the errors introduced when using histological sections to evaluate mass loss. METHODS Models of the SMP foams were created to mimic the device geometry and the tetrakaidekahedral structure of the foam pore. These models were degraded in Blender for a wide range of possible degradation amounts and the mass loss was estimated using m sections. RESULTS As the number of sections (m) used to estimate mass loss for a volume increased the sampling error decreased and beyond m = 5, the decrease in error was insignificant. NED population and sampling errors were higher than for PED scenarios. When m ≥ 5, the averaged sampling error was below 1.5% for NED and 1% for PED scenarios. DISCUSSION/CONCLUSION This study establishes a baseline sampling error for estimating randomly degraded porous scaffolds using a sectional method. Device geometry and the stage of mass loss influence the sampling error. Future studies will use non-random degradation to further investigate in vivo mass loss scenarios.
Collapse
Affiliation(s)
- Lance M Graul
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
| | - Shuling Liu
- Department of Statistics, Texas A&M University, College Station, TX, United States
| | - Duncan J Maitland
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States.
| |
Collapse
|
8
|
Shi W, Li H, Mitchell K, Zhang C, Zhu T, Jin Y, Zhao D. A multi-dimensional non-uniform corrosion model for bioabsorbable metallic vascular stents. Acta Biomater 2021; 131:572-580. [PMID: 34265472 DOI: 10.1016/j.actbio.2021.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 06/30/2021] [Accepted: 07/02/2021] [Indexed: 12/17/2022]
Abstract
Bioabsorbable metallic vascular stents (BMVSs) are an innovative technological advancement in the medical engineering field of vascular implants. BMVSs have great potential to revolutionize vascular intervention, but the lack of understanding of the construction material's natural corrosion within the body inhibits the use in clinical medicine. In this study, a corrosion function concept for in vivo implants was created to develop a multi-dimensional, non-uniform corrosion model with a larger goal of simulating the mechanical integrity of BMVSs. This proposed corrosion model simulates the corrosion rate and its effects on magnesium (Mg) alloy AZ31 based on continuum damage mechanics. The model was calibrated using three degradation experiments on Mg alloy specimens. These experiments focused on multi-dimensional corrosion, mass loss rate, and mechanical integrity during the corrosion process. Lastly, to verify the applicability of the proposed model, the resulting corrosion behaviors and mechanical characteristics of the BMVSs were implemented into a finite element framework to produce an overarching simulation of the BMVS's degradation in vivo. The results of the experiments and simulations revealed a proportional link between the corrosion of BMVSs and the number of exposed surfaces. A non-linear decline in mechanical integrity with increasing mass loss was also discovered through experimentation and modeling. Furthermore, the model and simulation can provide some details about changes in morphology and mechanics during BMVS corrosion. This work gives new insights into accurately modeling for BMVS degradation and can be used to optimize product development of BMVSs. STATEMENT OF SIGNIFICANCE: Bioabsorbable metallic vascular stents (BMVSs) are an innovative technological advancement in the medical engineering field of vascular implants. Despite BMVSs have great potential to revolutionize vascular intervention, the lack of understanding of the construction material's natural corrosion within the body inhibits their use in clinical medicine. In this study, a novel multi-dimensional non-uniform corrosion model was proposed to unveil the mechanisms during the in vivo degradation of bioabsorbable metallic implants, which can accurately capture the overlooked changes in morphology and mechanics during BMVS corrosion. This work provides a technical solution to enhance the modeling accuracy in BMVS degradation and can be further used to optimize the design of BMVSs in the future.
Collapse
Affiliation(s)
- Weiliang Shi
- Key Laboratory for Precision & Non-traditional Machining Technology of Ministry of Education, Dalian University of Technology, No.2 Linggong Road, Dalian, Liaoning 116024, China
| | - Hongxia Li
- Key Laboratory for Precision & Non-traditional Machining Technology of Ministry of Education, Dalian University of Technology, No.2 Linggong Road, Dalian, Liaoning 116024, China
| | - Kellen Mitchell
- Department of Mechanical Engineering, University of Nevada Reno, Reno, NV 89557, USA
| | - Cheng Zhang
- Key Laboratory for Precision & Non-traditional Machining Technology of Ministry of Education, Dalian University of Technology, No.2 Linggong Road, Dalian, Liaoning 116024, China
| | - Tingzhun Zhu
- Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang 110016, China
| | - Yifei Jin
- Department of Mechanical Engineering, University of Nevada Reno, Reno, NV 89557, USA.
| | - Danyang Zhao
- Key Laboratory for Precision & Non-traditional Machining Technology of Ministry of Education, Dalian University of Technology, No.2 Linggong Road, Dalian, Liaoning 116024, China.
| |
Collapse
|
9
|
A Physical Approach to Simulate the Corrosion of Ceramic-Coated Magnesium Implants. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11156724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Magnesium-based biodegradable materials are currently of great interest in various biomedical applications, especially those related to the treatment of bone trauma and the manufacturing of bone implants. Due to the complexity of the degradation process of magnesium, several numerical models were developed to help predict the change of the implant’s integrity in the body using in vitro tests. In this study, experimental in vitro tests and finite element methods are combined to calibrate a diffusion-based model of the uniform galvanic corrosion of high purity magnesium (HP-Mg). In addition, and for the first time, the impact of a porous coating layer generated by the Micro Arc oxidation (MAO) method is investigated and incorporated into the model. The calibrated model parameters are validated using the same immersion test conditions on a near-standard of treatment screws geometry made of HP-Mg.
Collapse
|
10
|
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.
Collapse
|
11
|
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.
Collapse
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.
| |
Collapse
|