Pub Date : 2024-11-23DOI: 10.1016/j.jmbbm.2024.106818
M.A. Oude Vrielink , P.H.M. Timmermans , B. van de Wetering , R. Hovenkamp , O. van der Sluis
During intravascular procedures, medical devices interact mechanically with vascular tissue. The device design faces a trade-off: although a high bending stiffness improves its maneuvrability and deliverability, it may also trigger excessive supra-physiological loading that may result in tissue damage. In particular, the collagen fibers in vascular walls are load-bearing but may rupture on a microscopic scale due to mechanical interaction. When the mechanical load increases even further, tissue rupture or puncture occurs. To mitigate tissue damage, the current work focusses on the development of computational Finite Element (FE) based models wherein state-of-the-art constitutive tissue models are applied toward the design of safe devices. Several experiments are presented for tissue characterization in which device-mimicking indenters are pressed onto a porcine tissue. In these experiments, the Mullins effect, which is related to tissue damage, is observed. Consequently, the mechanical behavior of tissue, including the evolution of damage-induced energy dissipation, is accurately described by adopting a hyperelastic model incorporating the damage approach by Weisbecker et al. (2012). From the experimentally validated computational model, a novel design criterion is established, which allows for safe device development. Furthermore, an energy density criterion for the onset of puncture is proposed. With these tools, several frequently used work-horse guidewires are numerically evaluated.
{"title":"Computational modeling of vascular tissue damage for the development of safe interventional devices","authors":"M.A. Oude Vrielink , P.H.M. Timmermans , B. van de Wetering , R. Hovenkamp , O. van der Sluis","doi":"10.1016/j.jmbbm.2024.106818","DOIUrl":"10.1016/j.jmbbm.2024.106818","url":null,"abstract":"<div><div>During intravascular procedures, medical devices interact mechanically with vascular tissue. The device design faces a trade-off: although a high bending stiffness improves its maneuvrability and deliverability, it may also trigger excessive supra-physiological loading that may result in tissue damage. In particular, the collagen fibers in vascular walls are load-bearing but may rupture on a microscopic scale due to mechanical interaction. When the mechanical load increases even further, tissue rupture or puncture occurs. To mitigate tissue damage, the current work focusses on the development of computational Finite Element (FE) based models wherein state-of-the-art constitutive tissue models are applied toward the design of safe devices. Several experiments are presented for tissue characterization in which device-mimicking indenters are pressed onto a porcine tissue. In these experiments, the Mullins effect, which is related to tissue damage, is observed. Consequently, the mechanical behavior of tissue, including the evolution of damage-induced energy dissipation, is accurately described by adopting a hyperelastic model incorporating the damage approach by Weisbecker et al. (2012). From the experimentally validated computational model, a novel design criterion is established, which allows for safe device development. Furthermore, an energy density criterion for the onset of puncture is proposed. With these tools, several frequently used work-horse guidewires are numerically evaluated.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106818"},"PeriodicalIF":3.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.jmbbm.2024.106819
C. Pereira-Lobato , M. Echeverry-Rendón , J.P. Fernández-Blázquez , J. LLorca , C. González
Composites manufactured with textiles weaved with commingled yarns using PLA (polylactic acid) and PCL (polycaprolactone) fibres are promising candidates for connective tissue engineering. In this work, textiles were fabricated using PLA/PCL commingled yarns in a ratio of 3 to 1, which were subsequently consolidated by compression moulding to produce solid composite plates. Specimens were extracted from the composite plates and submitted to degradation testing by immersion in PBS fluid (phosphate-buffered saline) at different periods. The dry mass, mechanical performance (tensile tests), thermal properties and molecular weight evolution, and cell compatibility by direct and indirect testing were evaluated and discussed. The results obtained demonstrated the material viability for connective tissue (tendon/ligament) repair and substitution.
{"title":"PLA/PCL composites manufactured from commingled yarns for biomedical applications","authors":"C. Pereira-Lobato , M. Echeverry-Rendón , J.P. Fernández-Blázquez , J. LLorca , C. González","doi":"10.1016/j.jmbbm.2024.106819","DOIUrl":"10.1016/j.jmbbm.2024.106819","url":null,"abstract":"<div><div>Composites manufactured with textiles weaved with commingled yarns using PLA (polylactic acid) and PCL (polycaprolactone) fibres are promising candidates for connective tissue engineering. In this work, textiles were fabricated using PLA/PCL commingled yarns in a ratio of 3 to 1, which were subsequently consolidated by compression moulding to produce solid composite plates. Specimens were extracted from the composite plates and submitted to degradation testing by immersion in PBS fluid (phosphate-buffered saline) at different periods. The dry mass, mechanical performance (tensile tests), thermal properties and molecular weight evolution, and cell compatibility by direct and indirect testing were evaluated and discussed. The results obtained demonstrated the material viability for connective tissue (tendon/ligament) repair and substitution.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106819"},"PeriodicalIF":3.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oral drug delivery is the Holy Grail in the field of drug delivery. However, poor bioavailability limits the oral intake of macromolecular drugs. Oral devices may overcome this limitation, but a knowledge gap exists on the device-tissue interaction. This study focuses on needle insertion into the human stomach experimentally and numerically. This will guide early stages of device development.
Methods
Needle insertions were done into excised human gastric tissue with sharp and blunt needles at velocities of 0.0001 and 0.1 m/s. Parameters for constitutive models were determined from tensile visco-hyperelastic biomechanical tests. The computational setup modeled four different needle shape indentations at five velocities from 0.0001 to 5 m/s.
Results
From experiments, peak forces at 0.1 and 0.0001 m/s were 0.995 ± 0.296 N and 1.281 ± 0.670 N (blunt needle) and 0.325 ± 0.235 N and 0.362 ± 0.119 N (sharp needle). The needle geometry significantly influenced peak forces (p < 0.05). A Yeoh-Prony series combination was fitted to the tensile visco-hyperelastic biomechanical data and used for the numerical model with excellent fit (R2 = 0.973). Both needle geometry and insertion velocity influenced the stress contour and displacement magnitudes as well as energy curves.
Conclusion
This study contributes to a better understanding of needle insertion into the stomach wall. The numerical model demonstrated agreement with experimental data providing a good approach to early device iterations. Findings in this study showed that insertion velocity and needle shape affect tissue mechanical outcomes.
{"title":"Experimental and numerical study of solid needle insertions into human stomach tissue","authors":"Sif Julie Friis , Torben Stroem Hansen , Camilla Olesen , Mette Poulsen , Hans Gregersen , Jens Vinge Nygaard","doi":"10.1016/j.jmbbm.2024.106832","DOIUrl":"10.1016/j.jmbbm.2024.106832","url":null,"abstract":"<div><h3>Purpose</h3><div>Oral drug delivery is the Holy Grail in the field of drug delivery. However, poor bioavailability limits the oral intake of macromolecular drugs. Oral devices may overcome this limitation, but a knowledge gap exists on the device-tissue interaction. This study focuses on needle insertion into the human stomach experimentally and numerically. This will guide early stages of device development.</div></div><div><h3>Methods</h3><div>Needle insertions were done into excised human gastric tissue with sharp and blunt needles at velocities of 0.0001 and 0.1 m/s. Parameters for constitutive models were determined from tensile visco-hyperelastic biomechanical tests. The computational setup modeled four different needle shape indentations at five velocities from 0.0001 to 5 m/s.</div></div><div><h3>Results</h3><div>From experiments, peak forces at 0.1 and 0.0001 m/s were 0.995 ± 0.296 N and 1.281 ± 0.670 N (blunt needle) and 0.325 ± 0.235 N and 0.362 ± 0.119 N (sharp needle). The needle geometry significantly influenced peak forces (p < 0.05). A Yeoh-Prony series combination was fitted to the tensile visco-hyperelastic biomechanical data and used for the numerical model with excellent fit (R<sup>2</sup> = 0.973). Both needle geometry and insertion velocity influenced the stress contour and displacement magnitudes as well as energy curves.</div></div><div><h3>Conclusion</h3><div>This study contributes to a better understanding of needle insertion into the stomach wall. The numerical model demonstrated agreement with experimental data providing a good approach to early device iterations. Findings in this study showed that insertion velocity and needle shape affect tissue mechanical outcomes.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"162 ","pages":"Article 106832"},"PeriodicalIF":3.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1016/j.jmbbm.2024.106830
A.C. Moser , J. Fritz , A. Kesselring , F. Schüssler , A. Otahal , S. Nehrer
Objective
To investigate the suitability of different material compositions and structural designs for 3D-printed meniscus implants using finite element analysis (FEA) to improve joint function after meniscal injury and guide future implant development.
Design
This experimental study involved in-silico testing of a meniscus model developed from two materials: a specially formulated hydrogel composed of silk fibroin (SF), gelatine, and decellularized meniscus-derived extracellular matrix (MD-dECM), and polyurethane (PU) with stiffness levels of 54 and 205 MPa. Both single-material implants and a two-volumetric meniscus model with an SF/gelatine/MD-dECM core and a PU shell were analysed using FEA to simulate the biomechanical performance under physiological conditions.
Results
The hydrogel alone was found to be unsuitable for long-term use due to instability in material properties beyond two weeks. PU 54 closely replicated the biomechanical properties of an intact meniscus, particularly in terms of contact pressure and stress distribution. However, hybrid implants combining PU 54 with hydrogel showed potential but required further optimization to reduce stress peaks. In contrast, implants with a PU 205 shell generated higher induced stresses, increasing the risk of material failure.
Conclusions
FEA proves to be a valuable tool in the design and optimization of meniscal implants. The findings suggest that softer PU 54 is a promising material for mimicking natural meniscus properties, while stiffer materials may require design modifications to mitigate stress concentrations. These insights are crucial for refining implant designs and selecting appropriate material combinations before physical prototype production, potentially reducing costs, time, and the risk of implant failure.
目的利用有限元分析（FEA）研究不同材料成分和结构设计对 3D 打印半月板植入物的适用性，以改善半月板损伤后的关节功能并指导未来的植入物开发。设计这项实验研究包括对由两种材料制成的半月板模型进行室内测试：一种是由丝纤维蛋白（SF）、明胶和脱细胞半月板细胞外基质（MD-dECM）组成的特殊配方水凝胶，另一种是刚度分别为 54 和 205 兆帕的聚氨酯（PU）。使用有限元分析法分析了单一材料植入物和具有 SF/ 凝胶/MD-dECM 内核和聚氨酯外壳的双体积半月板模型，以模拟生理条件下的生物力学性能。PU 54 密切复制了完整半月板的生物力学特性，尤其是在接触压力和应力分布方面。不过，结合了 PU 54 和水凝胶的混合植入体显示出了潜力，但需要进一步优化以降低应力峰值。与此相反，带有 PU 205 外壳的植入体会产生更高的诱导应力，增加材料失效的风险。研究结果表明，较软的 PU 54 是模拟天然半月板特性的理想材料，而较硬的材料可能需要进行设计修改，以减轻应力集中。这些见解对完善植入物设计和在物理原型生产前选择合适的材料组合至关重要，有可能降低成本、缩短时间并降低植入物失效的风险。
{"title":"Biomechanical testing of virtual meniscus implants made from a bi-phasic silk fibroin-based hydrogel and polyurethane via finite element analysis","authors":"A.C. Moser , J. Fritz , A. Kesselring , F. Schüssler , A. Otahal , S. Nehrer","doi":"10.1016/j.jmbbm.2024.106830","DOIUrl":"10.1016/j.jmbbm.2024.106830","url":null,"abstract":"<div><h3>Objective</h3><div>To investigate the suitability of different material compositions and structural designs for 3D-printed meniscus implants using finite element analysis (FEA) to improve joint function after meniscal injury and guide future implant development.</div></div><div><h3>Design</h3><div>This experimental study involved in-silico testing of a meniscus model developed from two materials: a specially formulated hydrogel composed of silk fibroin (SF), gelatine, and decellularized meniscus-derived extracellular matrix (MD-dECM), and polyurethane (PU) with stiffness levels of 54 and 205 MPa. Both single-material implants and a two-volumetric meniscus model with an SF/gelatine/MD-dECM core and a PU shell were analysed using FEA to simulate the biomechanical performance under physiological conditions.</div></div><div><h3>Results</h3><div>The hydrogel alone was found to be unsuitable for long-term use due to instability in material properties beyond two weeks. PU 54 closely replicated the biomechanical properties of an intact meniscus, particularly in terms of contact pressure and stress distribution. However, hybrid implants combining PU 54 with hydrogel showed potential but required further optimization to reduce stress peaks. In contrast, implants with a PU 205 shell generated higher induced stresses, increasing the risk of material failure.</div></div><div><h3>Conclusions</h3><div>FEA proves to be a valuable tool in the design and optimization of meniscal implants. The findings suggest that softer PU 54 is a promising material for mimicking natural meniscus properties, while stiffer materials may require design modifications to mitigate stress concentrations. These insights are crucial for refining implant designs and selecting appropriate material combinations before physical prototype production, potentially reducing costs, time, and the risk of implant failure.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"162 ","pages":"Article 106830"},"PeriodicalIF":3.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.jmbbm.2024.106821
Lilibeth A. Zambrano M , Nele Famaey , Michael Gilchrist , Aislin Ní Annaidh
The mechanical properties of the human skull have been examined and established previously in the literature, for example, the transversal isotropy of cranial bone and properties including the Elastic modulus and Poisson's ratio. However, despite the existing data, there are still mechanical properties which remain to be determined for the human skull. The present study aims to characterise the fracture properties of human cranial bone within the Linear Elastic Fracture Mechanics (LEFM) framework. Unembalmed human (2 female and 3 male) cortical cranial bone samples were harvested from the frontal, and left and right parietal bones and were tested in Mode I (N = 124), Mode II (N = 31) and Mixed-Mode I-II (N = 47) loading conditions. For Mode I, samples were tested using Single Edge Notched Beams (SENB) under symmetric 3-point bending, while for Mixed-Mode I-II samples were tested under asymmetric 3-point bending. For Mode II, 4-point bend tests were carried out. All samples fractured in a brittle fashion. From these tests, reference values of stress intensity factor (KI and KII) and the strain energy release rate (JI, GI, GII, GI-II) for the frontal, left and right parietal bones were calculated. It was determined that the fracture toughness of the frontal, and left and right parietal bones are not statistically different from each other and that they exhibit symmetry about the sagittal plane. It was also demonstrated that, as is the case for other human bones and for the age range tested here, the fracture toughness of human cranial bone is lower for females (KIfemale 2.48 (±2.16) MPa∗m0.5, KImale 4.75 (±2.58) MPa∗m0.5, GIfemale 1.07 (±3.01) kJ/m2, GImale 1.85 (±1.93) kJ/m2, JIfemale 1.57 (1.89) kJ/m2 and JImale 4.03 (±3.32) kJ/m2) and varies with age. More experimental work should be carried out to confirm the extrapolation of these conclusions to the other fracture modes tested here.
Although these results are influenced by the age range and the age gap within the group of donors, the primary data presented here is valuable to those wishing to predict crack evolution and propagation in the human cranial bone and may prove useful in developing failure criterion or simulations of skull fracture using Finite Element Analysis.
{"title":"Fracture mechanics properties of human cranial bone","authors":"Lilibeth A. Zambrano M , Nele Famaey , Michael Gilchrist , Aislin Ní Annaidh","doi":"10.1016/j.jmbbm.2024.106821","DOIUrl":"10.1016/j.jmbbm.2024.106821","url":null,"abstract":"<div><div>The mechanical properties of the human skull have been examined and established previously in the literature, for example, the transversal isotropy of cranial bone and properties including the Elastic modulus and Poisson's ratio. However, despite the existing data, there are still mechanical properties which remain to be determined for the human skull. The present study aims to characterise the fracture properties of human cranial bone within the Linear Elastic Fracture Mechanics (LEFM) framework. Unembalmed human (2 female and 3 male) cortical cranial bone samples were harvested from the frontal, and left and right parietal bones and were tested in Mode I (N = 124), Mode II (N = 31) and Mixed-Mode I-II (N = 47) loading conditions. For Mode I, samples were tested using Single Edge Notched Beams (SENB) under symmetric 3-point bending, while for Mixed-Mode I-II samples were tested under asymmetric 3-point bending. For Mode II, 4-point bend tests were carried out. All samples fractured in a brittle fashion. From these tests, reference values of stress intensity factor (<em>K</em><sub><em>I</em></sub> and <em>K</em><sub><em>II</em></sub>) and the strain energy release rate (<em>J</em><sub><em>I</em></sub><em>, G</em><sub><em>I</em></sub><em>, G</em><sub><em>II</em></sub><em>, G</em><sub><em>I-II</em></sub>) for the frontal, left and right parietal bones were calculated. It was determined that the fracture toughness of the frontal, and left and right parietal bones are not statistically different from each other and that they exhibit symmetry about the sagittal plane. It was also demonstrated that, as is the case for other human bones and for the age range tested here, the fracture toughness of human cranial bone is lower for females (<em>K</em><sub><em>I</em></sub> <em>female</em> 2.48 (±2.16) MPa∗m<sup>0.5</sup>, <em>K</em><sub><em>I</em></sub> <em>male</em> 4.75 (±2.58) MPa∗m<sup>0.5</sup>, <em>G</em><sub><em>I</em></sub> <em>female</em> 1.07 (±3.01) kJ/m<sup>2</sup>, <em>G</em><sub><em>I</em></sub> <em>male</em> 1.85 (±1.93) kJ/m<sup>2</sup>, <em>J</em><sub><em>I</em></sub> <em>female</em> 1.57 (1.89) kJ/m<sup>2</sup> and <em>J</em><sub><em>I</em></sub> <em>male</em> 4.03 (±3.32) kJ/m<sup>2</sup>) and varies with age. More experimental work should be carried out to confirm the extrapolation of these conclusions to the other fracture modes tested here.</div><div>Although these results are influenced by the age range and the age gap within the group of donors, the primary data presented here is valuable to those wishing to predict crack evolution and propagation in the human cranial bone and may prove useful in developing failure criterion or simulations of skull fracture using Finite Element Analysis.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106821"},"PeriodicalIF":3.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bone pathologies such as osteoporosis and metastasis can significantly compromise the load-bearing capacity of the spinal column, increasing the risk of vertebral fractures, some of which may occur during routine physical activities. Currently, there is no clinical tool that accurately assesses the risk of vertebral fractures associated with these activities in osteoporotic and metastatic spines. In this paper, we develop and validate a quantitative computed tomography-based finite element analysis (QCT/FEA) method to predict vertebral fractures under general load conditions that simulate flexion, extension, and side-bending movements, reflecting the body's activities under various scenarios. Initially, QCT/FEA models of cadaveric spine cohorts were developed. The accuracy and verification of the methodology involved comparing the fracture force outcomes to those experimentally observed and measured under pure compression loading scenarios. The findings revealed a strong correlation between experimentally measured failure loads and those estimated computationally (R2 = 0.96, p < 0.001). For the selected vertebral specimens, we examined the effects of four distinct boundary conditions that replicate flexion, extension, left side-bending, and right side-bending loads. The results showed that spine bending load conditions led to over a 62% reduction in failure force outcomes compared to pure compression loading conditions (p ≤ 0.0143). The study also demonstrated asymmetrical strain distribution patterns when the loading condition shifted from pure compression to spine bending, resulting in larger strain values on one side of the bone and consequently reducing the failure load. The results of this study suggest that QCT/FEA can be effectively used to analyze various boundary conditions resembling real-world physical activities, providing a valuable tool for assessing vertebral fracture risks.
{"title":"Prediction of vertebral failure under general loadings of compression, flexion, extension, and side-bending","authors":"Mehran Fereydoonpour , Asghar Rezaei , Areonna Schreiber , Lichun Lu , Mariusz Ziejewski , Ghodrat Karami","doi":"10.1016/j.jmbbm.2024.106827","DOIUrl":"10.1016/j.jmbbm.2024.106827","url":null,"abstract":"<div><div>Bone pathologies such as osteoporosis and metastasis can significantly compromise the load-bearing capacity of the spinal column, increasing the risk of vertebral fractures, some of which may occur during routine physical activities. Currently, there is no clinical tool that accurately assesses the risk of vertebral fractures associated with these activities in osteoporotic and metastatic spines. In this paper, we develop and validate a quantitative computed tomography-based finite element analysis (QCT/FEA) method to predict vertebral fractures under general load conditions that simulate flexion, extension, and side-bending movements, reflecting the body's activities under various scenarios. Initially, QCT/FEA models of cadaveric spine cohorts were developed. The accuracy and verification of the methodology involved comparing the fracture force outcomes to those experimentally observed and measured under pure compression loading scenarios. The findings revealed a strong correlation between experimentally measured failure loads and those estimated computationally (R<sup>2</sup> = 0.96, p < 0.001). For the selected vertebral specimens, we examined the effects of four distinct boundary conditions that replicate flexion, extension, left side-bending, and right side-bending loads. The results showed that spine bending load conditions led to over a 62% reduction in failure force outcomes compared to pure compression loading conditions (p ≤ 0.0143). The study also demonstrated asymmetrical strain distribution patterns when the loading condition shifted from pure compression to spine bending, resulting in larger strain values on one side of the bone and consequently reducing the failure load. The results of this study suggest that QCT/FEA can be effectively used to analyze various boundary conditions resembling real-world physical activities, providing a valuable tool for assessing vertebral fracture risks.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"162 ","pages":"Article 106827"},"PeriodicalIF":3.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.jmbbm.2024.106829
Jiayi Ju , Yunhan Cai , Hao Gao , Tianyang Yang , Shengzhang Wang
Bicuspid aortic valve (BAV) patients are more predisposed to aortic regurgitation. Annuloplasty is a crucial therapeutic intervention, however, determining its ideal size remains a clinical challenge. This study aims to quantify the effects of varying annuloplasty sizes on treating BAV regurgitation, providing optimal size range for effective treatment while avoiding complications. Annuloplasty was simulated on a patient-specific BAV model using 19–27 mm diameter Hegar dilators to reduce the basal ring and elastic ring sutures to constrain it. Finite element simulation was performed to simulate BAV motion, followed by computational fluid dynamics simulation to obtain hemodynamic parameters at peak systole. Results show that as the basal ring size decreased, the leaflet coaptation area increased, accompanied by a reduction in maximum principal stress at the coaptation zone. However, the reduction in annuloplasty size significantly elevated the peak systolic flow velocity within the sinus, particularly near the basal ring, leading to a higher wall shear stress in the adjacent region. Moreover, an excessively small basal ring diameter induced a sharp increase in transvalvular pressure gradient. These findings suggest that the small-sized annuloplasty enhances BAV function and durability, whereas excessive ring reduction may aggravate mechanical burden on the aortic root, potentially resulting in long-term complications such as tissue damage and stenosis. Thus, these factors establish critical upper and lower limits for optimal annuloplasty sizing.
{"title":"Quantitative in silico analysis for patient-specific annuloplasty in bicuspid aortic valve regurgitation","authors":"Jiayi Ju , Yunhan Cai , Hao Gao , Tianyang Yang , Shengzhang Wang","doi":"10.1016/j.jmbbm.2024.106829","DOIUrl":"10.1016/j.jmbbm.2024.106829","url":null,"abstract":"<div><div>Bicuspid aortic valve (BAV) patients are more predisposed to aortic regurgitation. Annuloplasty is a crucial therapeutic intervention, however, determining its ideal size remains a clinical challenge. This study aims to quantify the effects of varying annuloplasty sizes on treating BAV regurgitation, providing optimal size range for effective treatment while avoiding complications. Annuloplasty was simulated on a patient-specific BAV model using 19–27 mm diameter Hegar dilators to reduce the basal ring and elastic ring sutures to constrain it. Finite element simulation was performed to simulate BAV motion, followed by computational fluid dynamics simulation to obtain hemodynamic parameters at peak systole. Results show that as the basal ring size decreased, the leaflet coaptation area increased, accompanied by a reduction in maximum principal stress at the coaptation zone. However, the reduction in annuloplasty size significantly elevated the peak systolic flow velocity within the sinus, particularly near the basal ring, leading to a higher wall shear stress in the adjacent region. Moreover, an excessively small basal ring diameter induced a sharp increase in transvalvular pressure gradient. These findings suggest that the small-sized annuloplasty enhances BAV function and durability, whereas excessive ring reduction may aggravate mechanical burden on the aortic root, potentially resulting in long-term complications such as tissue damage and stenosis. Thus, these factors establish critical upper and lower limits for optimal annuloplasty sizing.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"162 ","pages":"Article 106829"},"PeriodicalIF":3.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.jmbbm.2024.106826
Zaki Alomar , Morteza Aramesh , Andreas Thor , Cecilia Persson , Franco Concli , Francesco D'Elia
Additive manufacturing for fabrication of patient-specific oral and maxillofacial implants enables optimal fitting, significantly reducing surgery time and subsequent costs. However, it is still common to encounter hardware- or biological-related complications, specifically when radiation treatment is involved. For mandibular reconstruction plates, irradiated patients often experience plate loosening and subsequent plate exposure due to a decrease in the vascularity of the irradiated tissues. We hypothesize that an acceleration of the bone ingrowth prior to radiation treatment can increase the survival of such plates. In this work, a new design of a mandibular reconstruction plate is proposed to promote osseointegration, while providing the necessary mechanical support during healing. In this regard, six different Triply Periodic Minimal Surface (TPMS) structures were manufactured using laser-powder bed fusion. Three-point bending and in-vitro cell viability tests were performed. Mechanical testing demonstrated the ability for all structures to safely withstand documented biting forces, with favorable applicability for the Gyroid structure due its lower flexural modulus. Finally, cell viability tests confirmed high cell proliferation rate and good cell adhesion to the surface for all TPMS structures. Overall, the new design concept shows potential as a viable option for plates with improved functionality and higher survival rate.
{"title":"Towards improved functionality of mandibular reconstruction plates enabled by additively manufactured triply periodic minimal surface structures","authors":"Zaki Alomar , Morteza Aramesh , Andreas Thor , Cecilia Persson , Franco Concli , Francesco D'Elia","doi":"10.1016/j.jmbbm.2024.106826","DOIUrl":"10.1016/j.jmbbm.2024.106826","url":null,"abstract":"<div><div>Additive manufacturing for fabrication of patient-specific oral and maxillofacial implants enables optimal fitting, significantly reducing surgery time and subsequent costs. However, it is still common to encounter hardware- or biological-related complications, specifically when radiation treatment is involved. For mandibular reconstruction plates, irradiated patients often experience plate loosening and subsequent plate exposure due to a decrease in the vascularity of the irradiated tissues. We hypothesize that an acceleration of the bone ingrowth prior to radiation treatment can increase the survival of such plates. In this work, a new design of a mandibular reconstruction plate is proposed to promote osseointegration, while providing the necessary mechanical support during healing. In this regard, six different Triply Periodic Minimal Surface (TPMS) structures were manufactured using laser-powder bed fusion. Three-point bending and <em>in-vitro</em> cell viability tests were performed. Mechanical testing demonstrated the ability for all structures to safely withstand documented biting forces, with favorable applicability for the Gyroid structure due its lower flexural modulus. Finally, cell viability tests confirmed high cell proliferation rate and good cell adhesion to the surface for all TPMS structures. Overall, the new design concept shows potential as a viable option for plates with improved functionality and higher survival rate.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"162 ","pages":"Article 106826"},"PeriodicalIF":3.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.jmbbm.2024.106828
Jing Liu , Yinyang Shen , Kaikai Duan , Xiangming He , Ruoyu Wang , Yeping Chen , Ruoyu Li , Jialu Sun , Xiaoyi Qiu , Tao Chen , Jie Wang , Hui Wang
Clinical cardiac patches exhibit unsatisfied biocompatibility, low adhesion, and inadequate compliance and suboptimal mechanical properties for cardiac disorders repair. To address these challenges, herein we have innovatively proposed a biomimetic nanofiber electrospun membrane with a sandwich structure strategy. The composite patch comprises a stretchable polyurethane (PU) as basic material, then infiltrated with biocompatible silk fibroin methacryloyl (Silk-MA) as the middle layer via electrospinning and finally covered with Bio-ILs (chemically modified biocompatible ionic liquids) to impart electrical conductivity. Results indicated that the incorporation of Bio-ILs significantly enhances the conductivity reaching 2877 mS/m; particularly due to the positive charges of Bio-ILs, the composite film exhibits mild adhesive properties, inducing minimal damage to the substrate tissue. Furthermore, the basic PU of bilayer nanofiber membrane increased the film's stretching strain to approximately 250%, the Silk-MA hydrogel coating changed the film from hydrophobic to hydrophilic, creating a favorable and biocompatible microenvironment. Finally, in vitro experiments on cardiomyocytes confirmed that the material exhibits low cytotoxicity and excellent biocompatibility. Overall, the biomimetic sandwich electrospun membrane could restore electrical conduction and synchronized contraction function, providing a promising strategy for the treatment of cardiac tissue engineering.
{"title":"Novel biomimetic sandwich-structured electrospun cardiac patches with moderate adhesiveness and excellent electrical conductivity","authors":"Jing Liu , Yinyang Shen , Kaikai Duan , Xiangming He , Ruoyu Wang , Yeping Chen , Ruoyu Li , Jialu Sun , Xiaoyi Qiu , Tao Chen , Jie Wang , Hui Wang","doi":"10.1016/j.jmbbm.2024.106828","DOIUrl":"10.1016/j.jmbbm.2024.106828","url":null,"abstract":"<div><div>Clinical cardiac patches exhibit unsatisfied biocompatibility, low adhesion, and inadequate compliance and suboptimal mechanical properties for cardiac disorders repair. To address these challenges, herein we have innovatively proposed a biomimetic nanofiber electrospun membrane with a sandwich structure strategy. The composite patch comprises a stretchable polyurethane (PU) as basic material, then infiltrated with biocompatible silk fibroin methacryloyl (Silk-MA) as the middle layer via electrospinning and finally covered with Bio-ILs (chemically modified biocompatible ionic liquids) to impart electrical conductivity. Results indicated that the incorporation of Bio-ILs significantly enhances the conductivity reaching 2877 mS/m; particularly due to the positive charges of Bio-ILs, the composite film exhibits mild adhesive properties, inducing minimal damage to the substrate tissue. Furthermore, the basic PU of bilayer nanofiber membrane increased the film's stretching strain to approximately 250%, the Silk-MA hydrogel coating changed the film from hydrophobic to hydrophilic, creating a favorable and biocompatible microenvironment. Finally, in vitro experiments on cardiomyocytes confirmed that the material exhibits low cytotoxicity and excellent biocompatibility. Overall, the biomimetic sandwich electrospun membrane could restore electrical conduction and synchronized contraction function, providing a promising strategy for the treatment of cardiac tissue engineering.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106828"},"PeriodicalIF":3.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142796643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-19DOI: 10.1016/j.jmbbm.2024.106824
Audrey Berriot , Morgane Evin , Karim Kerkouche , Elisabeth Laroche , Eva Gerard , Eric Wagnac
Denticulate ligaments play a key role in stabilizing the spinal cord (SC). Accurate representation of these structures in finite element modelling, whether in quasi-static or dynamic conditions, is essential for providing biofidelic responses. Therefore, understanding, characterizing and comparing the tensile mechanical properties of denticulate ligaments at different loading velocities is crucial. A total of 38 denticulate ligament samples at different cervical levels (anatomical levels from C1 to C7) were obtained from 3 fresh porcine SCs and 86 uniaxial tensile tests were performed immediately after dissection using an electro-mechanical testing system equipped with a 22 N loadcell. The mechanical tests included 10 cycles of preconditioning and a ramp with displacement rates of 0.1 mm s−1, 1 mm s−1 and 10 mm s−1. Bilinear piecewise fitting and trilinear piecewise fitting were performed to determine the elastic modulus and maximum stress and strainof the samples. While no significant differences in the mechanical behavior of the denticulate ligaments were found across the different displacement rates, notable variations were found between spinal levels, with a significantly higher elastic modulus at the lower cervical levels.
齿状韧带在稳定脊髓（SC）方面发挥着关键作用。无论是在准静态还是动态条件下，在有限元建模中准确表示这些结构对于提供生物保真响应至关重要。因此，了解、描述和比较不同加载速度下的齿状韧带拉伸机械特性至关重要。我们从 3 头新鲜猪 SC 上获取了不同颈椎级别（解剖级别从 C1 到 C7）的共 38 个齿状韧带样本，并在解剖后立即使用配备 22 N 负载单元的电动机械测试系统进行了 86 次单轴拉伸测试。机械测试包括 10 个周期的预处理和位移速率为 0.1 mm s-1、1 mm s-1 和 10 mm s-1 的斜坡。通过双线性片断拟合和三线性片断拟合来确定样品的弹性模量以及最大应力和应变。虽然在不同的位移速率下，齿状韧带的机械行为没有发现明显的差异，但在不同脊柱水平之间发现了明显的差异，颈椎较低水平的弹性模量明显较高。
{"title":"Exploring the effect of displacement rate on the mechanical properties of denticulate ligaments through uniaxial tensile testing","authors":"Audrey Berriot , Morgane Evin , Karim Kerkouche , Elisabeth Laroche , Eva Gerard , Eric Wagnac","doi":"10.1016/j.jmbbm.2024.106824","DOIUrl":"10.1016/j.jmbbm.2024.106824","url":null,"abstract":"<div><div>Denticulate ligaments play a key role in stabilizing the spinal cord (SC). Accurate representation of these structures in finite element modelling, whether in quasi-static or dynamic conditions, is essential for providing biofidelic responses. Therefore, understanding, characterizing and comparing the tensile mechanical properties of denticulate ligaments at different loading velocities is crucial. A total of 38 denticulate ligament samples at different cervical levels (anatomical levels from C1 to C7) were obtained from 3 fresh porcine SCs and 86 uniaxial tensile tests were performed immediately after dissection using an electro-mechanical testing system equipped with a 22 N loadcell. The mechanical tests included 10 cycles of preconditioning and a ramp with displacement rates of 0.1 mm s<sup>−1</sup>, 1 mm s<sup>−1</sup> and 10 mm s<sup>−1</sup>. Bilinear piecewise fitting and trilinear piecewise fitting were performed to determine the elastic modulus and maximum stress and strainof the samples. While no significant differences in the mechanical behavior of the denticulate ligaments were found across the different displacement rates, notable variations were found between spinal levels, with a significantly higher elastic modulus at the lower cervical levels.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"162 ","pages":"Article 106824"},"PeriodicalIF":3.3,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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