Pub Date : 2026-05-01Epub Date: 2026-01-31DOI: 10.1016/j.jmbbm.2026.107356
S. Trusso , S. Firman , J. Balasubramanian , M.H. Khatami , H. de Haan , N.R. Agarwal
The synthesis and property characterization of soft biomaterials has taken precedence in recent years. Although bulk physical–chemical properties are well known for these bio-materials, nanoscale properties still need to be probed and evaluated to fine tune the bio-compatibility (structural as well as functional) with natural tissues for regenerative medicine, prosthetics and other biological applications. In this study, the focus is on a popular soft biomaterial, Elastin-like polypeptide (ELP) which has been prepared under different pH conditions. The topographical features of the ELP at the nanoscale using Atomic Force Microscopy (AFM) are explored. Additionally, the employment of a non linear mode of AFM called Intermodulation-AFM (ImAFM) to correlate the elastic properties (Young’s modulus) of ELP probed at the nanoscale with the topographical features gives us a deep insight into the mechanical properties offered by ELP when the structural features are altered by change in the ELP synthesis conditions namely, pH in this study. The noteworthy point is that these properties are measured at a spatial resolution of 0.9 nm. Finally, the change in the structural features of ELP with varying pH is discussed through atomistic Molecular Dynamics Simulations. The interaction mechanisms of the amino acid sequences and crosslinkers with proteins as they form the backbone and sidechain of the ELP at different pH are explored.
{"title":"Correlating topography and viscoelastic properties of elastin-like polypeptide scaffolds probed at the nanoscale: Intermodulation atomic force microscopy","authors":"S. Trusso , S. Firman , J. Balasubramanian , M.H. Khatami , H. de Haan , N.R. Agarwal","doi":"10.1016/j.jmbbm.2026.107356","DOIUrl":"10.1016/j.jmbbm.2026.107356","url":null,"abstract":"<div><div>The synthesis and property characterization of soft biomaterials has taken precedence in recent years. Although bulk physical–chemical properties are well known for these bio-materials, nanoscale properties still need to be probed and evaluated to fine tune the bio-compatibility (structural as well as functional) with natural tissues for regenerative medicine, prosthetics and other biological applications. In this study, the focus is on a popular soft biomaterial, Elastin-like polypeptide (ELP) which has been prepared under different pH conditions. The topographical features of the ELP at the nanoscale using Atomic Force Microscopy (AFM) are explored. Additionally, the employment of a non linear mode of AFM called Intermodulation-AFM (ImAFM) to correlate the elastic properties (Young’s modulus) of ELP probed at the nanoscale with the topographical features gives us a deep insight into the mechanical properties offered by ELP when the structural features are altered by change in the ELP synthesis conditions namely, pH in this study. The noteworthy point is that these properties are measured at a spatial resolution of 0.9 nm. Finally, the change in the structural features of ELP with varying pH is discussed through atomistic Molecular Dynamics Simulations. The interaction mechanisms of the amino acid sequences and crosslinkers with proteins as they form the backbone and sidechain of the ELP at different pH are explored.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"177 ","pages":"Article 107356"},"PeriodicalIF":3.5,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122699","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 : 2026-04-01Epub Date: 2026-01-15DOI: 10.1016/j.jmbbm.2026.107350
Brady D. Hislop , Kosar Safari , Muhammed M. Rahman , Chelsea M. Heveran , David M. Pierce , Ronald K. June
Osteochondral fluid transport likely plays a critical role in joint health and disease, yet the mechanical factors influencing this transport remain incompletely understood. This study established a finite element model of osteochondral fluid transport under cyclic compression, incorporating depth-dependent material properties and osmotic swelling. Using biphasic constitutive models for bone and cartilage, we simulated fluid flux across the osteochondral interface and performed a parametric sensitivity analysis of seven different mechanical properties. Results demonstrate that bone and cartilage permeability, as well as the stiffness of the collagen fiber network within cartilage, significantly affect net osteochondral fluid transport. Specifically, decreased cartilage permeability resulted in increased bone-to-cartilage ostechondral flow, and decreased collagen stiffness resulted in decreased net cartilage-to-bone fluid flow. Conversely, relatively high bone permeability reversed the direction of osteochondral flow. Other parameters, including bone modulus, bone solid volume fraction, cartilage shear modulus, and fixed charge density, had negligible effects. These findings highlight the importance of specific mechanical properties of both bone and cartilage in regulating osteochondral fluid transport and suggest that future studies should consider the complete osteochondral unit to better understand joint mechanobiology and osteoarthritis progression.
{"title":"Permeability of bone and cartilage, and stiffness of collagen within cartilage, influence osteochondral fluid transport during cyclic compression: A study in finite elements","authors":"Brady D. Hislop , Kosar Safari , Muhammed M. Rahman , Chelsea M. Heveran , David M. Pierce , Ronald K. June","doi":"10.1016/j.jmbbm.2026.107350","DOIUrl":"10.1016/j.jmbbm.2026.107350","url":null,"abstract":"<div><div>Osteochondral fluid transport likely plays a critical role in joint health and disease, yet the mechanical factors influencing this transport remain incompletely understood. This study established a finite element model of osteochondral fluid transport under cyclic compression, incorporating depth-dependent material properties and osmotic swelling. Using biphasic constitutive models for bone and cartilage, we simulated fluid flux across the osteochondral interface and performed a parametric sensitivity analysis of seven different mechanical properties. Results demonstrate that bone and cartilage permeability, as well as the stiffness of the collagen fiber network within cartilage, significantly affect net osteochondral fluid transport. Specifically, decreased cartilage permeability resulted in increased bone-to-cartilage ostechondral flow, and decreased collagen stiffness resulted in decreased net cartilage-to-bone fluid flow. Conversely, relatively high bone permeability reversed the direction of osteochondral flow. Other parameters, including bone modulus, bone solid volume fraction, cartilage shear modulus, and fixed charge density, had negligible effects. These findings highlight the importance of specific mechanical properties of both bone and cartilage in regulating osteochondral fluid transport and suggest that future studies should consider the complete osteochondral unit to better understand joint mechanobiology and osteoarthritis progression.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107350"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000222","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 : 2026-04-01Epub Date: 2026-01-07DOI: 10.1016/j.jmbbm.2026.107341
Luke T. Mattar , Svenja A. Höger , Anja M. Wackerle , Jayson J. Baggett , Armin Runer , Kevin G. Shea , Volker Musahl , Richard E. Debski
The objective was to quantify the mechanical properties of the central region of skeletally immature human patellar tendons and the associations with age. Twenty-six patella-patellar tendon complexes were examined (range 0.1–9.9 years, 17 males, 9 females). The cross-sectional area at the midsubstance of the native and dog-boned patellar tendons were measured using a 3D laser scanning system. The patellar tendons underwent a mechanical testing protocol to failure with loading criteria normalized to cross-sectional area. Associations between mechanical properties, native cross-sectional area, and age were determined using Pearson or Spearman's correlations. The only association observed between age and mechanical properties was a positive association between age and ultimate stress (R2 = 0.21, p = 0.02), thus as age increased, the ultimate stress increased. No association between age and modulus was found (p > 0.05). A positive association between age and native cross-sectional area was observed (R2 = 0.64, p = 0.001). Furthermore, 46 % of specimens lacked a typical toe region of the stress-strain curve. Increased ultimate stress with age may indicate the patellar tendon adapts throughout maturation to increase the force per unit area withstood before failing. In combination with the increases in native cross-sectional area, the patellar tendon may adapt to increased loading occurring at the knee throughout maturation at the macrostructural and microstructural levels. The lack of a toe region in some patellar tendons may indicate additional differences in tissue architecture such as smaller collagen crimp angles, more collagen cross-linking, or lower elastin concentrations. Thus, the current study provides information on changes in tissue function throughout growth and development.
目的是量化骨未成熟人类髌骨肌腱中心区域的力学特性及其与年龄的关系。对26例髌骨-髌骨肌腱复合体进行了检查（年龄范围0.1-9.9岁，男性17例，女性9例）。使用3D激光扫描系统测量原生和狗骨髌骨肌腱中间物质的横截面积。髌骨肌腱进行了力学测试，加载标准归一化为横截面积。力学性能、自然横截面积和年龄之间的关系采用Pearson或Spearman相关来确定。年龄与力学性能之间的唯一相关关系是年龄与极限应力之间的正相关关系（R2 = 0.21, p = 0.02），因此随着年龄的增加，极限应力增加。年龄与模量之间无相关性（p > 0.05）。年龄与原生横截面积呈正相关（R2 = 0.64, p = 0.001）。此外，46%的试件缺乏典型的应力-应变曲线脚趾区域。随着年龄增长而增加的极限应力可能表明髌腱在整个成熟过程中适应在失效前增加单位面积承受的力。结合固有横截面积的增加，髌骨肌腱可以在宏观结构和微观结构水平上适应膝关节在成熟过程中增加的负荷。某些髌骨肌腱缺少趾区可能表明组织结构存在其他差异，如胶原卷曲角度较小、胶原交联较多或弹性蛋白浓度较低。因此，目前的研究提供了在生长发育过程中组织功能变化的信息。
{"title":"Associations between age and mechanical properties in skeletally immature human patellar tendons","authors":"Luke T. Mattar , Svenja A. Höger , Anja M. Wackerle , Jayson J. Baggett , Armin Runer , Kevin G. Shea , Volker Musahl , Richard E. Debski","doi":"10.1016/j.jmbbm.2026.107341","DOIUrl":"10.1016/j.jmbbm.2026.107341","url":null,"abstract":"<div><div>The objective was to quantify the mechanical properties of the central region of skeletally immature human patellar tendons and the associations with age. Twenty-six patella-patellar tendon complexes were examined (range 0.1–9.9 years, 17 males, 9 females). The cross-sectional area at the midsubstance of the native and dog-boned patellar tendons were measured using a 3D laser scanning system. The patellar tendons underwent a mechanical testing protocol to failure with loading criteria normalized to cross-sectional area. Associations between mechanical properties, native cross-sectional area, and age were determined using Pearson or Spearman's correlations. The only association observed between age and mechanical properties was a positive association between age and ultimate stress (R<sup>2</sup> = 0.21, p = 0.02), thus as age increased, the ultimate stress increased. No association between age and modulus was found (p > 0.05). A positive association between age and native cross-sectional area was observed (R<sup>2</sup> = 0.64, p = 0.001). Furthermore, 46 % of specimens lacked a typical toe region of the stress-strain curve. Increased ultimate stress with age may indicate the patellar tendon adapts throughout maturation to increase the force per unit area withstood before failing. In combination with the increases in native cross-sectional area, the patellar tendon may adapt to increased loading occurring at the knee throughout maturation at the macrostructural and microstructural levels. The lack of a toe region in some patellar tendons may indicate additional differences in tissue architecture such as smaller collagen crimp angles, more collagen cross-linking, or lower elastin concentrations. Thus, the current study provides information on changes in tissue function throughout growth and development.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107341"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923523","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 : 2026-04-01Epub Date: 2026-01-29DOI: 10.1016/j.jmbbm.2026.107355
Yi Huang , Yan Xu , Jialu Li , Zhipeng Deng , Xinmiao Feng , Rixiang Quan , Weiting Xu , Xiaolong Chen , James P.K. Armstrong , Massimo Caputo , Cian Vyas , Paulo Bartolo , Fengyuan Liu , Giovanni Biglino
Cardiovascular stents are widely applied in the treatment of arterial stenosis, but conventional metallic stents present limitations such as permanent implantation, hypersensitivity reactions, and late restenosis. Biodegradable polymer stents offer a promising alternative, though their translation is restricted by structural design challenges and inadequate mechanical performance. In this study, eight representative stent architectures were computationally evaluated with respect to radial elastic recoil, foreshortening, dogboning, and radial support force. Stents were fabricated from polylactide (PLA) via fused deposition modelling (FDM), and the effects of nozzle temperature, layer height, and printing speed were systematically assessed on PLA dogbone specimens to determine optimised process parameters. Computational analysis revealed that only type B and type F stents met clinical deformation requirements, with radial elastic recoil <6 %, foreshortening <10 %, and dogboning <10 %, while other designs exhibited values exceeding these thresholds. Parallel compression tests further quantified radial support capacity at 50 % compression. Fabrication and dimensional evaluation showed that, although all stent designs could be produced using optimised FDM parameters, manufacturing-induced geometric deviations at thin struts and unit connection regions were unavoidable. As a result, the finite-element simulations should be regarded as providing idealised mechanical responses for comparative design evaluation rather than exact predictions of fabricated prototypes. Overall, these findings provide structural and process design guidelines for the development of mechanically reliable 3D-printed biodegradable PLA cardiovascular stents, while emphasising the importance of manufacturing fidelity when translating computationally optimised designs into physical devices.
{"title":"Computational analysis of mechanical performance for 3D-printed biodegradable PLA cardiovascular stents","authors":"Yi Huang , Yan Xu , Jialu Li , Zhipeng Deng , Xinmiao Feng , Rixiang Quan , Weiting Xu , Xiaolong Chen , James P.K. Armstrong , Massimo Caputo , Cian Vyas , Paulo Bartolo , Fengyuan Liu , Giovanni Biglino","doi":"10.1016/j.jmbbm.2026.107355","DOIUrl":"10.1016/j.jmbbm.2026.107355","url":null,"abstract":"<div><div>Cardiovascular stents are widely applied in the treatment of arterial stenosis, but conventional metallic stents present limitations such as permanent implantation, hypersensitivity reactions, and late restenosis. Biodegradable polymer stents offer a promising alternative, though their translation is restricted by structural design challenges and inadequate mechanical performance. In this study, eight representative stent architectures were computationally evaluated with respect to radial elastic recoil, foreshortening, dogboning, and radial support force. Stents were fabricated from polylactide (PLA) via fused deposition modelling (FDM), and the effects of nozzle temperature, layer height, and printing speed were systematically assessed on PLA dogbone specimens to determine optimised process parameters. Computational analysis revealed that only type B and type F stents met clinical deformation requirements, with radial elastic recoil <6 %, foreshortening <10 %, and dogboning <10 %, while other designs exhibited values exceeding these thresholds. Parallel compression tests further quantified radial support capacity at 50 % compression. Fabrication and dimensional evaluation showed that, although all stent designs could be produced using optimised FDM parameters, manufacturing-induced geometric deviations at thin struts and unit connection regions were unavoidable. As a result, the finite-element simulations should be regarded as providing idealised mechanical responses for comparative design evaluation rather than exact predictions of fabricated prototypes. Overall, these findings provide structural and process design guidelines for the development of mechanically reliable 3D-printed biodegradable PLA cardiovascular stents, while emphasising the importance of manufacturing fidelity when translating computationally optimised designs into physical devices.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107355"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074203","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 : 2026-04-01Epub Date: 2026-01-08DOI: 10.1016/j.jmbbm.2026.107342
Chao Sun , Hao Deng , Xinyue Yang , Li Zhou , Yonggang Yan , Qiyi Zhang
Magnesium phosphate cement (MPC) is promising for bone repair but limited by high curing temperature, rapid setting, and brittleness. This study developed an organic-inorganic composite MPC incorporating CaCl2•6H2O and oxidized cellulose/carboxymethyl chitosan (OCMC/CMCS) gel to address these issues. The effect of OCMC/CMCS content on composite properties was investigated. The formulation with 5 % OCMC/CMCS (5 %-O) demonstrated optimal performance: lower setting temperature (∼31 °C), prolonged setting time (30.92 ± 0.95 min), adequate compressive strength (11.21 ± 2.34 MPa), improved toughness, injectability (87.64 ± 1.69 %), and enhanced degradation (27.89 ± 0.83 % on day 28). It also exhibited significant antibacterial activity against S. aureus (inhibition rate 82.79 ± 0.68 %) and antioxidant capacity (maximum scavenging rates of 38.64 ± 3.20 % for DPPH and 100 % for ABTS), while maintaining good biocompatibility and osteogenic potential. This composite shows a significant potential for cancellous bone repair.
{"title":"An organic-inorganic composite bone cement based on oxidized carboxymethyl cellulose/carboxymethyl chitosan hydrogel and magnesium phosphate with excellent antibacterial and antioxidant properties","authors":"Chao Sun , Hao Deng , Xinyue Yang , Li Zhou , Yonggang Yan , Qiyi Zhang","doi":"10.1016/j.jmbbm.2026.107342","DOIUrl":"10.1016/j.jmbbm.2026.107342","url":null,"abstract":"<div><div>Magnesium phosphate cement (MPC) is promising for bone repair but limited by high curing temperature, rapid setting, and brittleness. This study developed an organic-inorganic composite MPC incorporating CaCl<sub>2</sub>•6H<sub>2</sub>O and oxidized cellulose/carboxymethyl chitosan (OCMC/CMCS) gel to address these issues. The effect of OCMC/CMCS content on composite properties was investigated. The formulation with 5 % OCMC/CMCS (5 %-O) demonstrated optimal performance: lower setting temperature (∼31 °C), prolonged setting time (30.92 ± 0.95 min), adequate compressive strength (11.21 ± 2.34 MPa), improved toughness, injectability (87.64 ± 1.69 %), and enhanced degradation (27.89 ± 0.83 % on day 28). It also exhibited significant antibacterial activity against <em>S. aureus</em> (inhibition rate 82.79 ± 0.68 %) and antioxidant capacity (maximum scavenging rates of 38.64 ± 3.20 % for DPPH and 100 % for ABTS), while maintaining good biocompatibility and osteogenic potential. This composite shows a significant potential for cancellous bone repair.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107342"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923571","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}
Understanding conical penetration into layered biological materials requires capturing the coupled influences of anisotropy, curvature, layer architecture, and developmental evolution of material properties. However, existing computational studies typically assume adult bone, neglect multilayer skull structure, or simplify cortical anisotropy. Here, we develop a multilayer finite element framework that integrates age-dependent cortical thickness, diploë formation, anisotropic elastic behavior, and Hill-type anisotropic yield to resolve penetration mechanics across developmental stages. A data-driven strategy is used to estimate geometry and material properties by fitting a monomolecular growth model to experimental measurements of thickness, modulus, and strength spanning infancy through adulthood, producing a continuous and physiologically realistic map of skull property evolution. The model is validated against independent wedge-indentation experiments and reference finite element simulations, demonstrating close agreement in force-displacement behavior and subsurface stress distributions. Results reveal that age-driven changes in cortical thickness and stiffness produce more than a three-fold variation in penetration depth and a four-fold variation in penetration depth as a percentage of the outer cortical layer thickness, under identical loading. Marked differences in shear-stress localization and plastic-zone morphology highlight how layer geometry and anisotropic stiffness collectively govern penetration resistance. These findings provide new mechanistic insight into the indentation response and pin slippage of layered cranial bone and underscore the importance of age-specific material modeling. The framework has direct implications for biomechanical safety when using head-immobilization devices, particularly in pediatric neurosurgery, where predictive modeling of tool-bone interaction can inform improved device design, force recommendations, and clinical practice.
{"title":"A multilayer, anisotropy-aware, age-dependent finite element framework for pin-skull indentation mechanics with implications for pediatric cranial safety","authors":"Moataz Abdulhafez , Karim Kadry , Mohamed Zaazoue , Mostafa Bedewy","doi":"10.1016/j.jmbbm.2026.107343","DOIUrl":"10.1016/j.jmbbm.2026.107343","url":null,"abstract":"<div><div>Understanding conical penetration into layered biological materials requires capturing the coupled influences of anisotropy, curvature, layer architecture, and developmental evolution of material properties. However, existing computational studies typically assume adult bone, neglect multilayer skull structure, or simplify cortical anisotropy. Here, we develop a multilayer finite element framework that integrates age-dependent cortical thickness, diploë formation, anisotropic elastic behavior, and Hill-type anisotropic yield to resolve penetration mechanics across developmental stages. A data-driven strategy is used to estimate geometry and material properties by fitting a monomolecular growth model to experimental measurements of thickness, modulus, and strength spanning infancy through adulthood, producing a continuous and physiologically realistic map of skull property evolution. The model is validated against independent wedge-indentation experiments and reference finite element simulations, demonstrating close agreement in force-displacement behavior and subsurface stress distributions. Results reveal that age-driven changes in cortical thickness and stiffness produce more than a three-fold variation in penetration depth and a four-fold variation in penetration depth as a percentage of the outer cortical layer thickness, under identical loading. Marked differences in shear-stress localization and plastic-zone morphology highlight how layer geometry and anisotropic stiffness collectively govern penetration resistance. These findings provide new mechanistic insight into the indentation response and pin slippage of layered cranial bone and underscore the importance of age-specific material modeling. The framework has direct implications for biomechanical safety when using head-immobilization devices, particularly in pediatric neurosurgery, where predictive modeling of tool-bone interaction can inform improved device design, force recommendations, and clinical practice.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107343"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923573","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 : 2026-04-01Epub Date: 2026-01-13DOI: 10.1016/j.jmbbm.2026.107345
Éva I. Lakatos, Róbert K. Németh
The most accurate understanding of the material properties of the trabecular bone tissue of the jawbone is essential for certain oral surgery procedures and for the design of bone replacement materials and implants. The material properties obtained from micro-structural analyses can be used to study the behavior of dental implants and other prostheses implanted in the jawbone. The structural anisotropy of trabecular bone samples from the jawbone was measured using the method of inserted ellipsoids. Using the developed method, it has been shown that bone samples from the close environment of the living tooth-root show anisotropy that can be effectively measured using micro-CT. In this article, we present a method that uses the eigenvalues of the fabric tensor describing structural anisotropy to generate a micro-structural frame model of the trabecular bone. A homogenization method is applied to describe macro-mechanical behavior of the orthotropic bone tissue, which uses the normal-, bending- and torsional stiffness of the beams in the elementary cell in an elastic spring model. With the homogenization of the frame model, the orthotropic material properties of the trabecular bone could be estimated. The method developed is demonstrated using the micro-CT of a bone sample with 0.2636 relative density. The eigenvalues of the fabric tensor of the sample were measured to be 0.5386, 0.3330 and 0.1306, which, after the homogenization of the elementary cell with an identical fabric tensor, resulted in a mechanically orthotropic macro-structure. The apparent moduli obtained were calculated to be 0.6920 GPa, 1.3668 GPa and 0.0503 GPa.
{"title":"Modeling the mechanical anisotropy in the trabecular bone with the measurement and consideration of the structural anisotropy","authors":"Éva I. Lakatos, Róbert K. Németh","doi":"10.1016/j.jmbbm.2026.107345","DOIUrl":"10.1016/j.jmbbm.2026.107345","url":null,"abstract":"<div><div>The most accurate understanding of the material properties of the trabecular bone tissue of the jawbone is essential for certain oral surgery procedures and for the design of bone replacement materials and implants. The material properties obtained from micro-structural analyses can be used to study the behavior of dental implants and other prostheses implanted in the jawbone. The structural anisotropy of trabecular bone samples from the jawbone was measured using the method of inserted ellipsoids. Using the developed method, it has been shown that bone samples from the close environment of the living tooth-root show anisotropy that can be effectively measured using micro-CT. In this article, we present a method that uses the eigenvalues of the fabric tensor describing structural anisotropy to generate a micro-structural frame model of the trabecular bone. A homogenization method is applied to describe macro-mechanical behavior of the orthotropic bone tissue, which uses the normal-, bending- and torsional stiffness of the beams in the elementary cell in an elastic spring model. With the homogenization of the frame model, the orthotropic material properties of the trabecular bone could be estimated. The method developed is demonstrated using the micro-CT of a bone sample with 0.2636 relative density. The eigenvalues of the fabric tensor of the sample were measured to be 0.5386, 0.3330 and 0.1306, which, after the homogenization of the elementary cell with an identical fabric tensor, resulted in a mechanically orthotropic macro-structure. The apparent moduli obtained were calculated to be 0.6920 GPa, 1.3668 GPa and 0.0503 GPa.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107345"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974712","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 : 2026-04-01Epub Date: 2026-01-12DOI: 10.1016/j.jmbbm.2026.107346
Kosar Safari , Ronald K. June , David M. Pierce
Hydrogels such as cell-seeded agarose provide versatile experimental systems for studying mechanobiological responses of chondrocytes, yet the intra-gel mechanical environment during loading remains poorly understood. In this study we aimed to quantify local mechanical cues within agarose constructs subjected to physiologically relevant loading conditions. We established sixty 3-D finite element simulations spanning five agarose concentrations from %, three loading modes (tension, compression, shear), two loading protocols (force- and displacement-controlled), and two magnitudes (low and high). We quantified spatial distributions of stresses, strains, strain energy densities, and fluid pressures to characterize intra-gel mechanics relevant to mechanotransduction in chondrocytes. Results revealed that even homogeneous constructs under simple cyclic loading generated heterogeneous local mechanical environments relevant to cartilage biology. Because gel stiffness scales with concentration, force-controlled loading maintains approximately constant stress while strain decreases with increasing stiffness. Conversely, displacement-controlled loading maintains constant strain while stress increases with increasing stiffness. This framework enables independent modulation of stress and strain when probing mechanobiology. Importantly, varying agarose concentration also mimics softening of the pericellular matrix during progression of osteoarthritis, thereby linking computational predictions to disease-relevant changes. These findings demonstrate that local mechanical cues differ fundamentally between force- and displacement-driven protocols and highlight the importance of accounting for spatial heterogeneity when interpreting experiments with homogeneous agarose constructs. By integrating computational modeling with experimental loading conditions, this study establishes a mechanistic framework to link intra-gel mechanics to responses of chondrocytes, providing both tools to advance understanding of chondrocyte/cartilage mechanobiology (thus also transcriptomics, proteomics, and metabolomics) and guidance for design of future experimental studies.
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Modeling of fasciae remains limited, despite their recognized role in chronic pain. Developing a comprehensive mechanical model of fasciae could significantly enhance our understanding of their pain-related mechanisms and improve their prevention. This paper presents a computational approach capable of simulating the mechanical behavior of fibrous tissues based on their mesostructure. The thoracolumbar fascia was selected as a case study due to the availability of its experimentally derived mechanical properties in the literature. A discrete element model was developed, representing collagen fibers as bilinear springs and the proteoglycan matrix as elastic beams. The model was subjected to uniaxial tensile tests across various parameter sets defining fiber threshold distributions. Four test configurations were implemented to evaluate key aspects of the model: the influence of fiber properties, validation against experimental data, anisotropic response, and the role of inter-fiber contact. The simulations revealed a broad range of hyperelastic behaviors resulting from subtle variations in fiber properties, suggesting potential adaptability across different fascia types. The numerical outcomes closely matched experimental results, despite the absence of a precise microstructural description of the tested samples. The model demonstrated anisotropic behavior aligned with the preferential fiber orientations, as expected in fibrous tissues. Additionally, contact interactions produced internal force reactions and localized stress within the sample. Overall, the proposed model successfully reproduced experimental tensile behavior while offering valuable insights into local mechanical responses and anisotropy, contributing to a better understanding of fascia mechanics and their potential role in chronic pain.
Significance statement
Growing evidence links chronic low back pain to altered mechanical properties of the thoracolumbar fascia. As fascia mechanics emerges from its fibrous mesostructure, elucidating this relationship is crucial. Yet, no existing numerical models directly derive macroscopic mechanical behavior from mesoscale structural organization. We developed a discrete element model that predicts the thoracolumbar fascia’s mechanical response from its mesostructural architecture. Validated against previous experimental tensile data, the model accurately reproduced the fascia’s elastic behavior. By quantitatively bridging mesostructure and mechanical response within the elastic range, this work provides a numerical framework to explore how fascial architecture governs the tissue mechanical properties which contribute to pain mechanisms.
{"title":"Modeling thoracolumbar fascia mechanical tensile behavior with microstructure-level descriptors","authors":"Alexandre Lagache , Jérémie Girardot , Claudio Vergari , Sébastien Laporte","doi":"10.1016/j.jmbbm.2025.107317","DOIUrl":"10.1016/j.jmbbm.2025.107317","url":null,"abstract":"<div><div>Modeling of fasciae remains limited, despite their recognized role in chronic pain. Developing a comprehensive mechanical model of fasciae could significantly enhance our understanding of their pain-related mechanisms and improve their prevention. This paper presents a computational approach capable of simulating the mechanical behavior of fibrous tissues based on their mesostructure. The thoracolumbar fascia was selected as a case study due to the availability of its experimentally derived mechanical properties in the literature. A discrete element model was developed, representing collagen fibers as bilinear springs and the proteoglycan matrix as elastic beams. The model was subjected to uniaxial tensile tests across various parameter sets defining fiber threshold distributions. Four test configurations were implemented to evaluate key aspects of the model: the influence of fiber properties, validation against experimental data, anisotropic response, and the role of inter-fiber contact. The simulations revealed a broad range of hyperelastic behaviors resulting from subtle variations in fiber properties, suggesting potential adaptability across different fascia types. The numerical outcomes closely matched experimental results, despite the absence of a precise microstructural description of the tested samples. The model demonstrated anisotropic behavior aligned with the preferential fiber orientations, as expected in fibrous tissues. Additionally, contact interactions produced internal force reactions and localized stress within the sample. Overall, the proposed model successfully reproduced experimental tensile behavior while offering valuable insights into local mechanical responses and anisotropy, contributing to a better understanding of fascia mechanics and their potential role in chronic pain.</div><div><strong>Significance statement</strong></div><div>Growing evidence links chronic low back pain to altered mechanical properties of the thoracolumbar fascia. As fascia mechanics emerges from its fibrous mesostructure, elucidating this relationship is crucial. Yet, no existing numerical models directly derive macroscopic mechanical behavior from mesoscale structural organization. We developed a discrete element model that predicts the thoracolumbar fascia’s mechanical response from its mesostructural architecture. Validated against previous experimental tensile data, the model accurately reproduced the fascia’s elastic behavior. By quantitatively bridging mesostructure and mechanical response within the elastic range, this work provides a numerical framework to explore how fascial architecture governs the tissue mechanical properties which contribute to pain mechanisms.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107317"},"PeriodicalIF":3.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923572","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 : 2026-04-01Epub Date: 2025-12-30DOI: 10.1016/j.jmbbm.2025.107328
Christoph Moos , Stefan Kolling , Bernd Wöstmann , Maximiliane Amelie Schlenz , Sebastian Wille
Objective:
Accurate simulation of prosthetic materials requires constitutive models that capture pressure sensitivity and tension–compression asymmetry beyond linear elasticity.
Methods:
This study presents a reverse-engineering workflow to calibrate a Drucker–Prager based constitutive model in LS-DYNA using the semi-analytical model for polymers MAT 187L SAMP Light for a resin composite (Brilliant Crios) and a polymer-infiltrated ceramic network (Vita Enamic). Unconfined uniaxial compression, three-point bending, and Brazilian disc tests provide elastic constants and strength measures that serve as inputs and calibration targets. An analytical initialization maps experimentally determined yield stresses to the linear Drucker–Prager yield surface, supplying reliable starting parameters for finite element reverse-engineering optimization.
Results:
The calibrated model captures the material response in the calibration tests (three-point bending and Brazilian disc) within the pre-peak regime, and an out-of-sample punch-through test confirms the transferability of the parameters without additional tuning. Compared to von Mises characterization approaches, the pressure-dependent characterization was achieved with only one additional test configuration, shifting effort from experiments to numerical computation optimization.
Significance:
Within these limits, the results support pressure-dependent, asymmetric plasticity as a practical basis for predictive finite element analysis of dental restoratives, while highlighting that explicit damage and strain-rate effects should be incorporated in future work to model softening and failure consistently.
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