Pub 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":"2026-01-31","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 : 2026-01-29DOI: 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":"2026-01-29","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 : 2026-01-15DOI: 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":"2026-01-15","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 : 2026-01-13DOI: 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":"2026-01-13","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 : 2026-01-12DOI: 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.
{"title":"Computational analyses of agarose constructs to establish mechanobiological conditions for experiments","authors":"Kosar Safari , Ronald K. June , David M. Pierce","doi":"10.1016/j.jmbbm.2026.107346","DOIUrl":"10.1016/j.jmbbm.2026.107346","url":null,"abstract":"<div><div>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 <span><math><mrow><mn>3</mn><mo>−</mo><mn>5</mn></mrow></math></span>%, 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.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107346"},"PeriodicalIF":3.5,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974714","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 : 2026-01-12DOI: 10.1016/j.jmbbm.2026.107349
Tianqi Wang , Xinyuan Shi , Shuanzhu Wang , Yongzhi Gong , Haiquan Feng
To investigate the influence of screw configuration of the distal fibular plate on the biomechanical effects of lateral malleolar oblique fractures. In this paper, multiple models were established using Computed Tomography (CT) data. Finite element analysis (FEA) was employed to compare the biomechanical characteristics (fracture-site displacement, fibular von Mises stress, and internal implant von Mises stress) of four internal fixation methods under different loading conditions (350N and 700N) and physiological conditions (20° dorsiflexion, 10° dorsiflexion, neutral, 10° plantarflexion, and 20° plantarflexion). In vitro experiments were performed for validation, and the results agreed well with the FEA predictions. The results indicated that the distal fibular plate with six screws yielded lower peak values of fracture-site displacement as well as lower peak fibular and internal implant von Mises stresses. Across physiological conditions, the lowest peak fracture-site displacement and the lowest peak fibular and internal implant von Mises stresses consistently occurred at 20° dorsiflexion. Moreover, all fixation configurations exhibited higher stability in dorsiflexion than in the neutral and plantarflexion positions. Overall, this study characterizes the stability and mechanical safety of distal fibular plate fixation under different physiological conditions during simulated daily standing, and may provide biomechanical evidence to support clinical fixation selection and postoperative rehabilitation planning for lateral malleolar fractures.
{"title":"The influence of the screw configuration of the distal fibular plate on the biomechanics of lateral malleolar oblique fractures","authors":"Tianqi Wang , Xinyuan Shi , Shuanzhu Wang , Yongzhi Gong , Haiquan Feng","doi":"10.1016/j.jmbbm.2026.107349","DOIUrl":"10.1016/j.jmbbm.2026.107349","url":null,"abstract":"<div><div>To investigate the influence of screw configuration of the distal fibular plate on the biomechanical effects of lateral malleolar oblique fractures. In this paper, multiple models were established using Computed Tomography (CT) data. Finite element analysis (FEA) was employed to compare the biomechanical characteristics (fracture-site displacement, fibular von Mises stress, and internal implant von Mises stress) of four internal fixation methods under different loading conditions (350N and 700N) and physiological conditions (20° dorsiflexion, 10° dorsiflexion, neutral, 10° plantarflexion, and 20° plantarflexion). In vitro experiments were performed for validation, and the results agreed well with the FEA predictions. The results indicated that the distal fibular plate with six screws yielded lower peak values of fracture-site displacement as well as lower peak fibular and internal implant von Mises stresses. Across physiological conditions, the lowest peak fracture-site displacement and the lowest peak fibular and internal implant von Mises stresses consistently occurred at 20° dorsiflexion. Moreover, all fixation configurations exhibited higher stability in dorsiflexion than in the neutral and plantarflexion positions. Overall, this study characterizes the stability and mechanical safety of distal fibular plate fixation under different physiological conditions during simulated daily standing, and may provide biomechanical evidence to support clinical fixation selection and postoperative rehabilitation planning for lateral malleolar fractures.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107349"},"PeriodicalIF":3.5,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974715","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 : 2026-01-08DOI: 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":"2026-01-08","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":"2026-01-08","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 : 2026-01-08DOI: 10.1016/j.jmbbm.2026.107340
Luis A. Castro , Dongfang E. Chen , Aidan O'Scannlain , Krashn K. Dwivedi , Keshav A. Kailash , Jacob Rother , Christie L. Crandall , Robyn A. Roth , Carmen M. Halabi , Jessica E. Wagenseil
Elastic fibers are critical for proper mechanical function of large arteries such as the aorta. Fragmentation, degradation, or reduced amounts of elastic fibers are associated with aortic diseases such as stiffening-induced hypertension and aneurysms. Epigallocatechin gallate (EGCG) is a plant-based polyphenol that has been shown to increase elastic fiber synthesis, preventing stiffening-induced hypertension and alleviating abdominal aortic aneurysms. EGCG is similar in structure to another polyphenol, pentagalloyl glucose, that has been shown to increase elastic fiber synthesis and prevent elastic fiber degradation. The effects of EGCG on elastic fiber degradation have not been previously investigated. In this study, elastase (ELA) was used to degrade elastic fibers in the mouse ascending aorta and the preventative and restorative potential of EGCG was determined by characterizing the passive, circumferential mechanical behavior and microstructural organization of the aortic wall. EGCG treatment alone had no effect on the mechanical behavior or microstructural organization of the aortic wall. ELA treatment alone resulted in increased aortic diameter, altered aortic compliance, reduced low modulus, increased high modulus, and decreased density of the elastic fiber layers in the wall. EGCG as a preventative treatment before ELA partially prevented the changes in mechanical behavior and wall structure observed with ELA. EGCG as a restorative treatment after ELA did not prevent the changes in mechanical behavior and wall structure associated with ELA. These results suggest that EGCG may be an effective preventative pharmaceutical treatment option for cardiovascular diseases that are characterized by elastic fiber degradation.
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Pub Date : 2026-01-08DOI: 10.1016/j.jmbbm.2026.107333
Nele Demeersseman , David Nolan , Aoife Glynn , Francesco Digeronimo , Yasmine Guendouz , Nele Famaey , Caitríona Lally
A detailed understanding of cerebral artery biomechanics is essential for advancing cerebrovascular research and neurovascular device development. Yet, despite the clinical relevance of these vessels, high-fidelity experimental data remains extremely limited. As a result, current device development is often informed by data from non-cerebral vessels or animals. To address this gap, this study characterized the mechanical behavior and structural composition of human middle cerebral arteries obtained from six donors. Ring-extension testing was used to quantify elastin- and collagen-dominant region stiffnesses, while histological staining was used to assess elastin, collagen, and smooth muscle cell (SMC) content. Histology revealed that, unlike large elastic arteries, cerebral arteries are dominated by SMCs, contain sparse elastin, and lack a distinct external elastic lamina. Comparative analysis showed that mechanical behavior could not be inferred from composition alone, highlighting the importance of considering tissue integrity and organization when assessing structure. To explore clinically relevant differences, samples were grouped by cardiovascular disease (CVD) status and arterial branch type (M1 vs. M2). CVD-affected arteries exhibited significantly higher elastin-dominant region stiffness and reduced medial SMC content (p < 0.05). M2 branches showed significantly lower collagen-dominant region stiffness, internal elastic lamina fraction, and adventitial collagen content compared to M1 branches (p < 0.05). These findings highlight the structural and mechanical heterogeneity of human cerebral arteries and suggest that neurovascular device design and deployment strategies might benefit from considering both disease state and anatomical location. By jointly evaluating mechanics and composition, this study provides a foundational dataset to guide future cerebrovascular research and device development.
详细了解脑动脉生物力学对于推进脑血管研究和神经血管装置的开发至关重要。然而，尽管这些血管具有临床意义，但高保真度的实验数据仍然非常有限。因此，目前的设备开发通常是由来自非脑血管或动物的数据提供信息的。为了解决这一空白，本研究对来自6个供体的人类大脑中动脉的力学行为和结构组成进行了表征。环延伸测试用于量化弹性蛋白和胶原蛋白主导区域的刚度，而组织学染色用于评估弹性蛋白、胶原蛋白和平滑肌细胞（SMC）的含量。组织学显示，与大弹性动脉不同，脑动脉以SMCs为主，含有稀疏的弹性蛋白，缺乏明显的外弹性层。对比分析表明，机械行为不能仅从成分推断，强调在评估结构时考虑组织完整性和组织的重要性。为了探讨临床相关差异，将样本按心血管疾病（CVD）状态和动脉分支类型（M1 vs. M2）分组。cvd影响动脉弹性蛋白主导区刚度显著升高，内侧SMC含量显著降低（p < 0.05）。与M1分支相比，M2分支的胶原优势区刚度、内部弹性层分数和外膜胶原含量显著降低（p < 0.05）。这些发现强调了人类大脑动脉的结构和力学异质性，并表明神经血管装置的设计和部署策略可能受益于考虑疾病状态和解剖位置。通过联合评估力学和成分，本研究为指导未来脑血管研究和设备开发提供了基础数据集。
{"title":"Experimental investigation of the microstructure and mechanics of human middle cerebral arteries","authors":"Nele Demeersseman , David Nolan , Aoife Glynn , Francesco Digeronimo , Yasmine Guendouz , Nele Famaey , Caitríona Lally","doi":"10.1016/j.jmbbm.2026.107333","DOIUrl":"10.1016/j.jmbbm.2026.107333","url":null,"abstract":"<div><div>A detailed understanding of cerebral artery biomechanics is essential for advancing cerebrovascular research and neurovascular device development. Yet, despite the clinical relevance of these vessels, high-fidelity experimental data remains extremely limited. As a result, current device development is often informed by data from non-cerebral vessels or animals. To address this gap, this study characterized the mechanical behavior and structural composition of human middle cerebral arteries obtained from six donors. Ring-extension testing was used to quantify elastin- and collagen-dominant region stiffnesses, while histological staining was used to assess elastin, collagen, and smooth muscle cell (SMC) content. Histology revealed that, unlike large elastic arteries, cerebral arteries are dominated by SMCs, contain sparse elastin, and lack a distinct external elastic lamina. Comparative analysis showed that mechanical behavior could not be inferred from composition alone, highlighting the importance of considering tissue integrity and organization when assessing structure. To explore clinically relevant differences, samples were grouped by cardiovascular disease (CVD) status and arterial branch type (M1 vs. M2). CVD-affected arteries exhibited significantly higher elastin-dominant region stiffness and reduced medial SMC content (p < 0.05). M2 branches showed significantly lower collagen-dominant region stiffness, internal elastic lamina fraction, and adventitial collagen content compared to M1 branches (p < 0.05). These findings highlight the structural and mechanical heterogeneity of human cerebral arteries and suggest that neurovascular device design and deployment strategies might benefit from considering both disease state and anatomical location. By jointly evaluating mechanics and composition, this study provides a foundational dataset to guide future cerebrovascular research and device development.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"176 ","pages":"Article 107333"},"PeriodicalIF":3.5,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974713","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}
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