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Yang X, Zhang W, Yao J, Sun A, Gao Y, Guo M, Fan Y. The differences between surface degradation and bulk degradation of FEM on the prediction of the degradation time for poly (lactic-co-glycolic acid) stent. Comput Methods Biomech Biomed Engin 2021; 25:65-72. [PMID: 34582282 DOI: 10.1080/10255842.2021.1931846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The degradation time is a crucial factor in evaluating the performance of poly (lactic-co-glycolic acid) (PLGA) stents. Bulk degradation mode was commonly used to analyze the stent degradation behavior by finite element approach. However, the PLGA stents may present surface degradation more than bulk degradation under certain conditions, which will greatly affect the degradation time after implantation. In this study, the degradation processes of the poly (lactic-co-glycolic acid) stent were reproduced utilizing finite element analysis. Both bulk degradation and surface degradation modes were considered. The correlation between tensile stress and degradation rate was investigated. The degradation time was analyzed selectively. The stress distribution, fracture, and mass loss were also compared between bulk degradation mode and surface degradation mode. The simulation results showed that, in both evolution modes, the degradation began at the 'peak-valley' region and fracture occurred at the cross of links and rings. Additionally, high levels of Von-Mises stress were observed in these two regions. Compared with bulk degradation, the fracture time of the stent was delayed by 63% in the surface degradation mode. In conclusion, the mass loss rate and scaffolding period showed great differences between surface degradation and bulk degradation. Based on this study, it is suggested that bulk degradation mode is not applicable to the case of inadequate water uptake mode, such as the tracheal stent degradation process. More experimental research should be carried out to accurately predict the scaffolding period after implantation. The mechanical properties of the fracture zone should be strengthened.
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Affiliation(s)
- Xianda Yang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Weirong Zhang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Jie Yao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Anqiang Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yuanming Gao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.,School of Engineering Medicine, Beihang University, Beijing, China
| | - Meng Guo
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.,School of Engineering Medicine, Beihang University, Beijing, China
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