Pub Date : 2026-03-01Epub Date: 2025-12-13DOI: 10.1016/j.jmbbm.2025.107313
Marek Trączyński , Katarzyna Rosłan , Natalia Budzińska , Marcin Suszyński , Rafał Talar
Hypodermic needle injections are widely used in clinical practice, yet the detailed morphology of skin punctures remains insufficiently characterized. This study aimed to investigate how needle size, insertion depth, sample storage time, and insertion angle influence the dimensions and shape of puncture wounds. Using porcine skin as a human tissue analog, over 200 needle insertions were conducted, and punctures were quantitatively analyzed through optical profilometry. Results demonstrated that puncture dimensions were consistently smaller than the needle's nominal size, indicating the significant influence of the skin's viscoelastic properties. Deeper insertions resulted in more extensive tissue disruption, while refrigerated tissues exhibited increased deformation compared to fresh ones. Additionally, rotating the needle around its axis altered the puncture geometry, reflecting the orientation of collagen fibers beneath the skin. The article also includes images of hypodermic needle skin holes at various stages of insertion, providing visual insight into puncture formation. These findings, together with the proposed theory on puncture formation in the skin caused by hypodermic needles, offer a basis for the development of more optimized injection techniques, with potential to support creation of reference wound-shape patterns.
{"title":"Shape analysis of post-extraction needle holes in porcine skin","authors":"Marek Trączyński , Katarzyna Rosłan , Natalia Budzińska , Marcin Suszyński , Rafał Talar","doi":"10.1016/j.jmbbm.2025.107313","DOIUrl":"10.1016/j.jmbbm.2025.107313","url":null,"abstract":"<div><div>Hypodermic needle injections are widely used in clinical practice, yet the detailed morphology of skin punctures remains insufficiently characterized. This study aimed to investigate how needle size, insertion depth, sample storage time, and insertion angle influence the dimensions and shape of puncture wounds. Using porcine skin as a human tissue analog, over 200 needle insertions were conducted, and punctures were quantitatively analyzed through optical profilometry. Results demonstrated that puncture dimensions were consistently smaller than the needle's nominal size, indicating the significant influence of the skin's viscoelastic properties. Deeper insertions resulted in more extensive tissue disruption, while refrigerated tissues exhibited increased deformation compared to fresh ones. Additionally, rotating the needle around its axis altered the puncture geometry, reflecting the orientation of collagen fibers beneath the skin. The article also includes images of hypodermic needle skin holes at various stages of insertion, providing visual insight into puncture formation. These findings, together with the proposed theory on puncture formation in the skin caused by hypodermic needles, offer a basis for the development of more optimized injection techniques, with potential to support creation of reference wound-shape patterns.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107313"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145795516","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 : 2026-03-01Epub Date: 2025-11-29DOI: 10.1016/j.jmbbm.2025.107290
Nikolaus Kronwitter, Angelika Rauch, Sebastian Hahnel, Martin Rosentritt
Aim
This study aimed to evaluate the effects of a translucency-enhancing liquid (TEL) and high-speed sintering (HS) on the mechanical behavior, with a focus on the survival rates and fracture forces of anterior zirconia crowns with different yttria contents.
Materials and methods
Anterior crowns (16 groups, n = 8 per group) were fabricated using four different zirconia materials (3Y-TZP, 4Y-TZP, 5Y-TZP, and multilayer (ML)). The 3Y and 4Y groups were treated with a TEL in three variations: no treatment (NL), two-layer penetration (2L), and four-layer penetration (4L). The 5Y-TZP and ML zirconia crowns served as reference groups without TEL treatment. All specimens underwent either conventional (CS) or high-speed (HS) sintering before being subjected to thermocyclic and mechanical loading (TCML), followed by a load-to-fracture test. Statistics: ANOVA, Bonferroni test, Shapiro-Wilk test, Pearson correlation; α = 0.05.
Results
Three specimens in group 5Y-NL-CS and one in group 4Y-NL-HS failed during TCML. Fracture forces varied significantly between different types of zirconia and decreased with increasing yttria content. While mean fracture forces were not affected by HS or TEL treatment, HS of ML and particularly 5Y-TZP crowns was associated with a higher frequency of crown fractures, indicating material- and condition-specific tendencies of potential clinical relevance.
Conclusion
Within the limitations of this in-vitro study - including the use of PMMA abutments, failures during TCML, and material- and failure-specific differences - all specimens withstood forces exceeding the physiological loads expected in the anterior region. Under these conditions, TEL treatment and HS of 3Y-TZP and 4Y-TZP zirconia appear to allow the rapid fabrication of anterior crowns while maintaining their mechanical performance. As optical parameters were not assessed, any potential aesthetic implications of TEL or HS cannot be inferred.
{"title":"Influence of sintering protocol and translucency-enhancing liquid on the mechanical performance of anterior zirconia crowns","authors":"Nikolaus Kronwitter, Angelika Rauch, Sebastian Hahnel, Martin Rosentritt","doi":"10.1016/j.jmbbm.2025.107290","DOIUrl":"10.1016/j.jmbbm.2025.107290","url":null,"abstract":"<div><h3>Aim</h3><div>This study aimed to evaluate the effects of a translucency-enhancing liquid (TEL) and high-speed sintering (HS) on the mechanical behavior, with a focus on the survival rates and fracture forces of anterior zirconia crowns with different yttria contents.</div></div><div><h3>Materials and methods</h3><div>Anterior crowns (16 groups, n = 8 per group) were fabricated using four different zirconia materials (3Y-TZP, 4Y-TZP, 5Y-TZP, and multilayer (ML)). The 3Y and 4Y groups were treated with a TEL in three variations: no treatment (NL), two-layer penetration (2L), and four-layer penetration (4L). The 5Y-TZP and ML zirconia crowns served as reference groups without TEL treatment. All specimens underwent either conventional (CS) or high-speed (HS) sintering before being subjected to thermocyclic and mechanical loading (TCML), followed by a load-to-fracture test. Statistics: ANOVA, Bonferroni test, Shapiro-Wilk test, Pearson correlation; α = 0.05.</div></div><div><h3>Results</h3><div>Three specimens in group 5Y-NL-CS and one in group 4Y-NL-HS failed during TCML. Fracture forces varied significantly between different types of zirconia and decreased with increasing yttria content. While mean fracture forces were not affected by HS or TEL treatment, HS of ML and particularly 5Y-TZP crowns was associated with a higher frequency of crown fractures, indicating material- and condition-specific tendencies of potential clinical relevance.</div></div><div><h3>Conclusion</h3><div>Within the limitations of this in-vitro study - including the use of PMMA abutments, failures during TCML, and material- and failure-specific differences - all specimens withstood forces exceeding the physiological loads expected in the anterior region. Under these conditions, TEL treatment and HS of 3Y-TZP and 4Y-TZP zirconia appear to allow the rapid fabrication of anterior crowns while maintaining their mechanical performance. As optical parameters were not assessed, any potential aesthetic implications of TEL or HS cannot be inferred.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107290"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623403","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 : 2026-03-01Epub Date: 2025-12-24DOI: 10.1016/j.jmbbm.2025.107324
Nafia Jawaid Kurd , Eraj Humayun Mirza , Tooba Khan , Muhammad Atiq ur Rehman , Muhammad Rizwan , Aftab Ahmed Khan , Abdulaziz Abdullah Alkhureif , Pekka K. Vallittu
This laboratory study aimed to synthesize and characterize various formulations of polyvinyl alcohol (PVA)-based hydrogels by incorporating 1.0 and 3.0 wt% of hyaluronic acid (HA) and zinc oxide (ZnO) nanoparticles (NPs) for skin wound healing. Six distinct PVA-HA based hydrogel formulations were developed with varying concentrations of ZnO (1 wt% and 3 wt%) using a freeze-thaw method comprising four cycles at −22 °C. The formulations were characterized through Fourier Transform Infrared Spectroscopy (FTIR), degradation analysis, moisture content analysis, pH sensitivity analysis, tensile strength testing, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and cell behavior assessment. Data were analyzed using one-way and two-way analysis of variance with a significance threshold set at 0.05. FTIR spectra confirmed functional groups that enhance the biocompatibility, mechanical stability, and hydrophobicity of the hydrogels. Among all the formulations, PVA-HA-ZnO 1 % demonstrated adequate durability and responsiveness to different pH conditions. The experimental hydrogels exhibited swelling in acidic environments, while shrinkage was observed in basic medium. A p-value of 0.005 in pH 6.5 vs 7.5 and a p-value of 0.0006 in pH 6.7 vs 8.1 was calculated. A significant difference in degradation characteristics was evident when HA was added to PVA (p-value of 0.04) and also when pure PVA was compared with samples containing both the ZnO and HA in conjugate (p-value of 0.03 for PVA vs PVA-HA-Zn01 % and p-value of 0.04 for PVA vs PVA-HA-ZnO3 %). Thermal stability testing indicated that increasing the concentration of ZnO NPs enhanced the thermal stability of the hydrogels, while the pure PVA formulation underperformed in thermal analysis. Additionally, the hydrogels facilitated adequate cell attachment; however, a higher concentration of ZnO NPs led to reduced cell attachment, indicating the cytotoxic behavior of ZnO. The hydrogel incorporating HA and 1 % ZnO demonstrated significant potential as a candidate for wound care applications, indicating the need for further investigation into its in vivo behavior and antimicrobial properties.
本实验室研究旨在通过加入1.0 wt%和3.0 wt%的透明质酸(HA)和氧化锌(ZnO)纳米颗粒(NPs)来合成和表征各种基于聚乙烯醇(PVA)的水凝胶配方,用于皮肤伤口愈合。六种不同的PVA-HA基水凝胶配方采用不同浓度的ZnO (1 wt%和3 wt%),使用冻融方法,包括在-22°C下进行四次循环。通过傅里叶红外光谱(FTIR)、降解分析、水分含量分析、pH敏感性分析、拉伸强度测试、热重分析(TGA)、差示扫描量热法(DSC)和细胞行为评估对配方进行了表征。数据分析采用单向和双向方差分析,显著性阈值设为0.05。FTIR光谱证实了增强水凝胶生物相容性、机械稳定性和疏水性的官能团。在所有的配方中,PVA-HA-ZnO 1%对不同的pH条件表现出足够的耐久性和响应性。实验水凝胶在酸性环境中表现为膨胀,在碱性环境中表现为收缩。pH值为6.5 vs 7.5的p值为0.005,pH值为6.7 vs 8.1的p值为0.0006。在PVA中添加HA (p值为0.04),以及在纯PVA中同时添加ZnO和HA (PVA vs PVA-HA- zno1% p值为0.03,PVA vs PVA-HA- zno3% p值为0.04)的样品中,降解特性有显著差异。热稳定性测试表明,增加ZnO NPs的浓度可以增强水凝胶的热稳定性,而纯PVA配方的热稳定性较差。此外,水凝胶有助于充分的细胞附着;然而,较高浓度的ZnO NPs导致细胞附着减少,表明ZnO具有细胞毒性行为。含有透明质酸和1%氧化锌的水凝胶显示出作为伤口护理应用的候选材料的巨大潜力,表明需要进一步研究其体内行为和抗菌性能。
{"title":"ZnO nanoparticles infused PVA-hyaluronic acid based hydrogel: An alternative solution for skin wound","authors":"Nafia Jawaid Kurd , Eraj Humayun Mirza , Tooba Khan , Muhammad Atiq ur Rehman , Muhammad Rizwan , Aftab Ahmed Khan , Abdulaziz Abdullah Alkhureif , Pekka K. Vallittu","doi":"10.1016/j.jmbbm.2025.107324","DOIUrl":"10.1016/j.jmbbm.2025.107324","url":null,"abstract":"<div><div>This laboratory study aimed to synthesize and characterize various formulations of polyvinyl alcohol (PVA)-based hydrogels by incorporating 1.0 and 3.0 wt% of hyaluronic acid (HA) and zinc oxide (ZnO) nanoparticles (NPs) for skin wound healing. Six distinct PVA-HA based hydrogel formulations were developed with varying concentrations of ZnO (1 wt% and 3 wt%) using a freeze-thaw method comprising four cycles at −22 °C. The formulations were characterized through Fourier Transform Infrared Spectroscopy (FTIR), degradation analysis, moisture content analysis, pH sensitivity analysis, tensile strength testing, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and cell behavior assessment. Data were analyzed using one-way and two-way analysis of variance with a significance threshold set at 0.05. FTIR spectra confirmed functional groups that enhance the biocompatibility, mechanical stability, and hydrophobicity of the hydrogels. Among all the formulations, PVA-HA-ZnO 1 % demonstrated adequate durability and responsiveness to different pH conditions. The experimental hydrogels exhibited swelling in acidic environments, while shrinkage was observed in basic medium. A <em>p-value</em> of 0.005 in pH 6.5 vs 7.5 and a <em>p-value</em> of 0.0006 in pH 6.7 vs 8.1 was calculated. A significant difference in degradation characteristics was evident when HA was added to PVA (<em>p-value</em> of 0.04) and also when pure PVA was compared with samples containing both the ZnO and HA in conjugate (<em>p-value</em> of 0.03 for PVA vs PVA-HA-Zn01 % and <em>p-value</em> of 0.04 for PVA vs PVA-HA-ZnO3 %). Thermal stability testing indicated that increasing the concentration of ZnO NPs enhanced the thermal stability of the hydrogels, while the pure PVA formulation underperformed in thermal analysis. Additionally, the hydrogels facilitated adequate cell attachment; however, a higher concentration of ZnO NPs led to reduced cell attachment, indicating the cytotoxic behavior of ZnO. The hydrogel incorporating HA and 1 % ZnO demonstrated significant potential as a candidate for wound care applications, indicating the need for further investigation into its <em>in vivo</em> behavior and antimicrobial properties.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107324"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145879906","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 : 2026-03-01Epub Date: 2025-12-29DOI: 10.1016/j.jmbbm.2025.107331
Laura Brose , Andreas Koenig , Paul Kemmesies , Saba Tamjidtash , Nadine Kommerein , Katharina Doll-Nikutta , Meike Stiesch , Martin Rosentritt , Sebastian Hahnel
Objectives
Understanding denture base material properties under aging conditions is crucial for assessing their clinical performance and impact on oral health. This study evaluated the behaviour of polymethylmethacrylate (PMMA), dimethacrylate-based polymers (DMA), and polyetheretherketone (PEEK) denture base materials after aging (thermal, mechanical, chemical), based on parameters (surface, mechanical, sorptive, structural) and considering manufacturing techniques (auto-curing, milling, 3D printing).
Material and methods
Disc-shaped specimens (2 mm × 8 mm, n = 10 per group; total n = 500) were manufactured from five denture base materials: PMMA (auto-curing, milling), DMA (3D printing: 90°/45° orientation), PEEK (milling). Standardized rough or fine surfaces were applied. Specimens underwent separate aging protocols: thermocycling, toothbrush abrasion, storage in HCl/NaOCl. Surface and material properties were analyzed prior and after aging. Data were evaluated using non-parametric tests (Kruskal-Wallis, Mann-Whitney U, α = 0.05). Effect sizes were calculated.
Results
Compared to other materials, PEEK showed few significant changes in surface parameters, microhardness, and indentation after aging. All materials exhibited strong effect sizes for water absorption and solubility (r ≥ 0.85∗∗∗). In PMMA, aging significantly reduced surface and mechanical properties, especially in rough-treated specimens. DMA printed with 90° was less affected by aging than with 45°, particularly after fine treatment. Milled PMMA with fine treatment showed the highest aging resistance among PMMA variants. Generally, rough surfaces were more susceptible to aging than fine surfaces.
Conclusion
Aging resistance of denture base materials depends on surface treatment, material, and manufacturing technique. Adequate polishing reduces aging effects on surface and mechanical properties. Milling yields reliable results, while 3D printing requires further optimization.
{"title":"Surface and microstructural properties of denture base materials: Effects of manufacturing techniques, surface treatments, and aging protocols","authors":"Laura Brose , Andreas Koenig , Paul Kemmesies , Saba Tamjidtash , Nadine Kommerein , Katharina Doll-Nikutta , Meike Stiesch , Martin Rosentritt , Sebastian Hahnel","doi":"10.1016/j.jmbbm.2025.107331","DOIUrl":"10.1016/j.jmbbm.2025.107331","url":null,"abstract":"<div><h3>Objectives</h3><div>Understanding denture base material properties under aging conditions is crucial for assessing their clinical performance and impact on oral health. This study evaluated the behaviour of polymethylmethacrylate (PMMA), dimethacrylate-based polymers (DMA), and polyetheretherketone (PEEK) denture base materials after aging (thermal, mechanical, chemical), based on parameters (surface, mechanical, sorptive, structural) and considering manufacturing techniques (auto-curing, milling, 3D printing).</div></div><div><h3>Material and methods</h3><div>Disc-shaped specimens (2 mm × 8 mm, n = 10 per group; total n = 500) were manufactured from five denture base materials: PMMA (auto-curing, milling), DMA (3D printing: 90°/45° orientation), PEEK (milling). Standardized rough or fine surfaces were applied. Specimens underwent separate aging protocols: thermocycling, toothbrush abrasion, storage in HCl/NaOCl. Surface and material properties were analyzed prior and after aging. Data were evaluated using non-parametric tests (Kruskal-Wallis, Mann-Whitney U, α = 0.05). Effect sizes were calculated.</div></div><div><h3>Results</h3><div>Compared to other materials, PEEK showed few significant changes in surface parameters, microhardness, and indentation after aging. All materials exhibited strong effect sizes for water absorption and solubility (r ≥ 0.85∗∗∗). In PMMA, aging significantly reduced surface and mechanical properties, especially in rough-treated specimens. DMA printed with 90° was less affected by aging than with 45°, particularly after fine treatment. Milled PMMA with fine treatment showed the highest aging resistance among PMMA variants. Generally, rough surfaces were more susceptible to aging than fine surfaces.</div></div><div><h3>Conclusion</h3><div>Aging resistance of denture base materials depends on surface treatment, material, and manufacturing technique. Adequate polishing reduces aging effects on surface and mechanical properties. Milling yields reliable results, while 3D printing requires further optimization.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107331"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880594","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 : 2026-03-01Epub Date: 2025-12-16DOI: 10.1016/j.jmbbm.2025.107316
Jesús Rodriguez-Molinero , María Prados-Privado
Background
Dental implant longevity depends on the complex interaction between mechanical stability and biological osseointegration. While finite element analysis (FEA) provides valuable mechanical insight, it remains static and computationally expensive.
Objective
This study presents a hybrid time-resolved computational framework combining finite element data, osseointegration dynamics, and deep learning to predict the biomechanical behavior of titanium dental implants throughout the healing process.
Methods
A parametric 3D FEA model simulated 800 implant–bone configurations varying in geometry, loading, and bone quality. A mechanobiological model of osseointegration described the monthly evolution of bone density, bone–implant contact (BIC), and interfacial stiffness over 12 months. These temporal variables were integrated into a hybrid Multilayer Perceptron – Long Short-Term Memory (MLP–LSTM) neural network — designed to capture both spatial and time-dependent features—trained to predict von Mises stress (), maximum displacement (), and fatigue safety factor (FSF, an indicator of long-term structural failure risk).
Results
The model achieved R2 > 0.98 for all outputs and mean absolute errors <0.015. Temporal simulation revealed that interfacial stiffness increased by 270 %, while FSF declined nonlinearly with load above 200 N. Predictions were generated in <0.01 s per case, offering >4000 × speed-up compared to conventional FEA.
Conclusions
The framework captures both mechanical and biological evolution of the implant–bone interface, providing physiologically realistic, computationally efficient predictions. This approach represents a step toward personalized, AI-assisted implant design and load management. Clinically, this tool allows for rapid pre-surgical screening of implant designs against patient-specific risk factors. Limitations include the reliance on synthetic data derived from simplified bone geometries, static loading assumptions, and unvalidated mechanobiological parameters, necessitating future in vivo validation. These findings represent a computational proof-of-concept and require validation against patient-specific geometries and biological data before clinical adoption.
{"title":"Time-resolved prediction of dental implant biomechanics through integration of finite element analysis, osseointegration dynamics, and deep learning","authors":"Jesús Rodriguez-Molinero , María Prados-Privado","doi":"10.1016/j.jmbbm.2025.107316","DOIUrl":"10.1016/j.jmbbm.2025.107316","url":null,"abstract":"<div><h3>Background</h3><div>Dental implant longevity depends on the complex interaction between mechanical stability and biological osseointegration. While finite element analysis (FEA) provides valuable mechanical insight, it remains static and computationally expensive.</div></div><div><h3>Objective</h3><div>This study presents a hybrid time-resolved computational framework combining finite element data, osseointegration dynamics, and deep learning to predict the biomechanical behavior of titanium dental implants throughout the healing process.</div></div><div><h3>Methods</h3><div>A parametric 3D FEA model simulated 800 implant–bone configurations varying in geometry, loading, and bone quality. A mechanobiological model of osseointegration described the monthly evolution of bone density, bone–implant contact (BIC), and interfacial stiffness over 12 months. These temporal variables were integrated into a hybrid Multilayer Perceptron – Long Short-Term Memory (MLP–LSTM) neural network — designed to capture both spatial and time-dependent features—trained to predict von Mises stress (<span><math><mrow><msub><mi>σ</mi><mrow><mi>V</mi><mi>M</mi></mrow></msub></mrow></math></span>), maximum displacement (<span><math><mrow><msub><mi>δ</mi><mi>max</mi></msub></mrow></math></span>), and fatigue safety factor (FSF, an indicator of long-term structural failure risk).</div></div><div><h3>Results</h3><div>The model achieved R<sup>2</sup> > 0.98 for all outputs and mean absolute errors <0.015. Temporal simulation revealed that interfacial stiffness increased by 270 %, while FSF declined nonlinearly with load above 200 N. Predictions were generated in <0.01 s per case, offering >4000 × speed-up compared to conventional FEA.</div></div><div><h3>Conclusions</h3><div>The framework captures both mechanical and biological evolution of the implant–bone interface, providing physiologically realistic, computationally efficient predictions. This approach represents a step toward personalized, AI-assisted implant design and load management. Clinically, this tool allows for rapid pre-surgical screening of implant designs against patient-specific risk factors. Limitations include the reliance on synthetic data derived from simplified bone geometries, static loading assumptions, and unvalidated mechanobiological parameters, necessitating future in vivo validation. These findings represent a computational proof-of-concept and require validation against patient-specific geometries and biological data before clinical adoption.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107316"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784198","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 : 2026-03-01Epub Date: 2025-12-01DOI: 10.1016/j.jmbbm.2025.107291
Lisa-Marie Skrip , Leonard Boerger , Kilian A. Walter , Alexander Arnold , Lene A. Böhne , Eriselda Keshi , Anna S. Pietsch , Nathanael Raschzok , Timo A. Auer , Uli Fehrenbach , Felix Krenzien , Johann Pratschke , Igor M. Sauer , Jing Guo , Jürgen Braun , Heiko Tzschätzsch , Ingolf Sack , Karl H. Hillebrandt , Simon Moosburner
Objective
Liver transplantation remains the primary treatment for end-stage liver disease, however, a shortage of suitable grafts persists. Factors contributing to this imbalance include insufficient organ quality, which exhibit higher complication rates, exacerbated by static cold storage. Normothermic Machine Perfusion (NMP) is proposed as an alternative, offering dynamic preservation, and quality assessment. This study introduces magnetic resonance elastography (MRE), to evaluate changes of viscoelastic properties of the liver after NMP for quality assessment.
Materials and methods
In this study, using a rat liver NMP model, we investigated whether older age and extended cold ischemia time (CIT) affect liver tissue properties after NMP. Ex vivo MRE measurements were conducted using a multifrequency tabletop 0.5-T MRE with excitation frequencies ranging from 500 Hz to 5300 Hz and viscoelastic model fitting with power-law exponent α.
Results
Samples of 24 Sprague Dawley rat livers were analyzed after 6- or 12-h of cold ischemia time and consequent 6-h NMP. All samples had predominantly viscous-fluid properties (ɑ>0.5). The powerlaw exponent ɑ was the highest in livers from 3-month-old rats and short cold ischemia (0.61, IQR 0.61–0.75) and lowest in long cold ischemia and older liver grafts (0.56, IQR 0.55–0.62; p < 0.001). Furthermore, shear modulus μ was significantly lower in 3-month-old rats and short cold ischemia than all other groups (p < 0.001).
Conclusion
Despite NMP, viscoelastic properties of liver tissues were still slightly impaired after extended CIT. MRE could serve as a diagnostic imaging tool, complementing MRI and pathological evaluation, for assessing the quality of liver grafts after NMP.
目的:肝移植仍然是终末期肝病的主要治疗方法,然而,仍然缺乏合适的移植物。造成这种不平衡的因素包括器官质量不足,这表现出较高的并发症发生率,并因静态冷藏而加剧。常温机器灌注(NMP)被建议作为一种替代方法,提供动态保存和质量评估。本研究引入磁共振弹性成像(MRE)技术,评价NMP后肝脏粘弹性的变化,用于质量评估。材料和方法:本研究采用大鼠肝脏NMP模型,研究年龄和延长冷缺血时间(CIT)对NMP后肝组织特性的影响。体外MRE测量采用多频台式0.5 t MRE,激励频率为500 Hz至5300 Hz,粘弹性模型拟合幂律指数α。结果:24只大鼠肝脏在冷缺血6、12小时后及随后的6小时NMP后进行分析。所有样品都具有主要的粘流体性质([]> .5])。3月龄短冷缺血大鼠肝脏的幂律指数最高(0.61,IQR为0.61 ~ 0.75),长冷缺血大鼠肝脏的幂律指数最低(0.56,IQR为0.55 ~ 0.62);p结论:尽管NMP,延长CIT后肝组织的粘弹性仍有轻微损伤,MRE可作为一种诊断成像工具,补充MRI和病理评价,用于评价NMP后肝移植质量。
{"title":"Assessing age and cold ischemia effects on liver tissue viscoelastic properties: Implications for graft quality assessment with MRE during machine perfusion","authors":"Lisa-Marie Skrip , Leonard Boerger , Kilian A. Walter , Alexander Arnold , Lene A. Böhne , Eriselda Keshi , Anna S. Pietsch , Nathanael Raschzok , Timo A. Auer , Uli Fehrenbach , Felix Krenzien , Johann Pratschke , Igor M. Sauer , Jing Guo , Jürgen Braun , Heiko Tzschätzsch , Ingolf Sack , Karl H. Hillebrandt , Simon Moosburner","doi":"10.1016/j.jmbbm.2025.107291","DOIUrl":"10.1016/j.jmbbm.2025.107291","url":null,"abstract":"<div><h3>Objective</h3><div>Liver transplantation remains the primary treatment for end-stage liver disease, however, a shortage of suitable grafts persists. Factors contributing to this imbalance include insufficient organ quality, which exhibit higher complication rates, exacerbated by static cold storage. Normothermic Machine Perfusion (NMP) is proposed as an alternative, offering dynamic preservation, and quality assessment. This study introduces magnetic resonance elastography (MRE), to evaluate changes of viscoelastic properties of the liver after NMP for quality assessment.</div></div><div><h3>Materials and methods</h3><div>In this study, using a rat liver NMP model, we investigated whether older age and extended cold ischemia time (CIT) affect liver tissue properties after NMP. <em>Ex vivo</em> MRE measurements were conducted using a multifrequency tabletop 0.5-T MRE with excitation frequencies ranging from 500 Hz to 5300 Hz and viscoelastic model fitting with power-law exponent <em>α</em>.</div></div><div><h3>Results</h3><div>Samples of 24 Sprague Dawley rat livers were analyzed after 6- or 12-h of cold ischemia time and consequent 6-h NMP. All samples had predominantly viscous-fluid properties (<em>ɑ</em>>0.5). The powerlaw exponent <em>ɑ</em> was the highest in livers from 3-month-old rats and short cold ischemia (0.61, IQR 0.61–0.75) and lowest in long cold ischemia and older liver grafts (0.56, IQR 0.55–0.62; p < 0.001). Furthermore, shear modulus <em>μ</em> was significantly lower in 3-month-old rats and short cold ischemia than all other groups (p < 0.001).</div></div><div><h3>Conclusion</h3><div>Despite NMP, viscoelastic properties of liver tissues were still slightly impaired after extended CIT. MRE could serve as a diagnostic imaging tool, complementing MRI and pathological evaluation, for assessing the quality of liver grafts after NMP.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107291"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145679922","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 : 2026-03-01Epub Date: 2025-12-03DOI: 10.1016/j.jmbbm.2025.107303
Hamed Hatami-Marbini, Md Esharuzzaman Emu
The primary objective of the present study was to characterize the species-specific effects of GAGs on the microstructure of corneal extracellular matrix (ECM). To this end, the keratanase enzyme was used to remove GAGs from human, pig, and mouse corneal ECM. Then, transmission electron microscopy (TEM) was done to determine the microstructure of samples before and after GAG depletion. In particular, TEM images were analyzed using ImageJ software to determine the diameter of collagen fibrils and interfibrillar spacing (IFS). An insignificant change in the average collagen fibril diameter of human (28.7 nm–>28.8 nm), porcine (34.7 nm–>35.2 nm), and murine (33.0 nm–>33.4 nm) was observed because of GAG depletion. The enzyme treatment significantly increased the average IFS from 45.8 nm, 53.0 nm, and 54.6 nm to 48.9 nm, 57.3 nm and 61.5 nm in human, porcine, and murine corneal samples, respectively (α < 0.05). The effects of GAGs on microstructural properties of corneal ECM were discussed in terms of their ability to form tiny bridges between collagen fibrils and their net negative charge density. It was concluded that, despite existing differences among collagen fibril diameter and IFS of human, porcine, and mouse cornea, GAG depletion showed relatively similar effects on the microstructure of their ECM. The findings of the present study may help explain the pathological effects associated with changes in GAG content and offer a basis for better understanding of interspecies variations in biomechanical response of cornea.
{"title":"Collagen fibril organization and its association with glycosaminoglycans in human, pig, and mouse cornea","authors":"Hamed Hatami-Marbini, Md Esharuzzaman Emu","doi":"10.1016/j.jmbbm.2025.107303","DOIUrl":"10.1016/j.jmbbm.2025.107303","url":null,"abstract":"<div><div>The primary objective of the present study was to characterize the species-specific effects of GAGs on the microstructure of corneal extracellular matrix (ECM). To this end, the keratanase enzyme was used to remove GAGs from human, pig, and mouse corneal ECM. Then, transmission electron microscopy (TEM) was done to determine the microstructure of samples before and after GAG depletion. In particular, TEM images were analyzed using ImageJ software to determine the diameter of collagen fibrils and interfibrillar spacing (IFS). An insignificant change in the average collagen fibril diameter of human (28.7 nm–>28.8 nm), porcine (34.7 nm–>35.2 nm), and murine (33.0 nm–>33.4 nm) was observed because of GAG depletion. The enzyme treatment significantly increased the average IFS from 45.8 nm, 53.0 nm, and 54.6 nm to 48.9 nm, 57.3 nm and 61.5 nm in human, porcine, and murine corneal samples, respectively (α < 0.05). The effects of GAGs on microstructural properties of corneal ECM were discussed in terms of their ability to form tiny bridges between collagen fibrils and their net negative charge density. It was concluded that, despite existing differences among collagen fibril diameter and IFS of human, porcine, and mouse cornea, GAG depletion showed relatively similar effects on the microstructure of their ECM. The findings of the present study may help explain the pathological effects associated with changes in GAG content and offer a basis for better understanding of interspecies variations in biomechanical response of cornea.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107303"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145835776","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 : 2026-03-01Epub Date: 2025-12-22DOI: 10.1016/j.jmbbm.2025.107323
Chloé Techens , Amira Ben Hassine , Edwin-Joffrey Courtial , David Eglin , Stéphane Avril
Smooth muscle cells (SMCs) of elastic arteries are essential to maintain mechanical homeostasis in the media layer. However, investigating the SMCs mechanoregulation mechanisms important to understand homeostasis and diseases progression, is hampered by a lack of in vitro model replicating realistic biological conditions. Indeed, previous studies have mainly been performed on 2D surfaces rather than in a 3D environment replicating more closely the tissue mechanics and composition. Thus, the objective of this study was to optimize a collagen hydrogel embedding SMCs 3D culture model where the “contractile” phenotype expressed by SMCs in healthy aortas, assessed by a spindle-shaped morphotype will be reproduced and conserved. A Design of Experiment (DoE) was established where 12 chemically different hydrogels were tested varying pH and collagen concentrations (7.4/7.7/8, 2.5/5.0/7.5/10.0 mg/mL) with 3 cell densities (50 000/100 000/150 000 cells/mL). SMCs contractile morphotype was optimal for low-collagen concentration hydrogels seeded at SMCs density of 100 000 cells/mL, independently of the hydrogel pH. The study provided an overview of the adaptation of the SMC population to the matrix shear modulus and viscosity, and provide a parameterized 3D model to study mechanoregulation of SMCs.
{"title":"Aortic smooth muscle cells keep their spindle-shaped morphotype in low density collagen hydrogels","authors":"Chloé Techens , Amira Ben Hassine , Edwin-Joffrey Courtial , David Eglin , Stéphane Avril","doi":"10.1016/j.jmbbm.2025.107323","DOIUrl":"10.1016/j.jmbbm.2025.107323","url":null,"abstract":"<div><div>Smooth muscle cells (SMCs) of elastic arteries are essential to maintain mechanical homeostasis in the media layer. However, investigating the SMCs mechanoregulation mechanisms important to understand homeostasis and diseases progression, is hampered by a lack of <em>in vitro</em> model replicating realistic biological conditions. Indeed, previous studies have mainly been performed on 2D surfaces rather than in a 3D environment replicating more closely the tissue mechanics and composition. Thus, the objective of this study was to optimize a collagen hydrogel embedding SMCs 3D culture model where the “contractile” phenotype expressed by SMCs in healthy aortas, assessed by a spindle-shaped morphotype will be reproduced and conserved. A Design of Experiment (DoE) was established where 12 chemically different hydrogels were tested varying pH and collagen concentrations (7.4/7.7/8, 2.5/5.0/7.5/10.0 mg/mL) with 3 cell densities (50 000/100 000/150 000 cells/mL). SMCs contractile morphotype was optimal for low-collagen concentration hydrogels seeded at SMCs density of 100 000 cells/mL, independently of the hydrogel pH. The study provided an overview of the adaptation of the SMC population to the matrix shear modulus and viscosity, and provide a parameterized 3D model to study mechanoregulation of SMCs.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107323"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145835746","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 : 2026-03-01Epub Date: 2025-11-28DOI: 10.1016/j.jmbbm.2025.107286
Swaprakash Yogeshwaran , Leila Donyaparastlivari , Ayda Pormoustafa , Vidhi Patel , Alexander Buffone , Rajarshi Chattaraj , Amir K. Miri
We present an inverse-engineering method for estimating physical forces within cell suspensions in 3D scaffolds during fabrication using fluorescent, lipid-coated microbubbles (MBs) filled with an inert fluorocarbon gas. MBs deform and rupture under significant mechanical pressure. In this work, we applied the compressibility characteristics of the MBs to estimate the forces acting on a cell-laden model during fabrication and handling. MBs were encapsulated in hydrogels and subjected to hydrostatic pressure for a specific period, and we demonstrated how calibration curves are generated to estimate the pressure around each MB. We further studied MB response via conventional ultrasound imaging and theoretical modeling. This work demonstrates a simple, scalable approach for estimating physical loads that biological cells experience during extrusion, injection, and other biofabrication processes.
{"title":"Microbubble-based indirect measurement of cell loading in hydrogel bioinks during handling of 3D models","authors":"Swaprakash Yogeshwaran , Leila Donyaparastlivari , Ayda Pormoustafa , Vidhi Patel , Alexander Buffone , Rajarshi Chattaraj , Amir K. Miri","doi":"10.1016/j.jmbbm.2025.107286","DOIUrl":"10.1016/j.jmbbm.2025.107286","url":null,"abstract":"<div><div>We present an inverse-engineering method for estimating physical forces within cell suspensions in 3D scaffolds during fabrication using fluorescent, lipid-coated microbubbles (MBs) filled with an inert fluorocarbon gas. MBs deform and rupture under significant mechanical pressure. In this work, we applied the compressibility characteristics of the MBs to estimate the forces acting on a cell-laden model during fabrication and handling. MBs were encapsulated in hydrogels and subjected to hydrostatic pressure for a specific period, and we demonstrated how calibration curves are generated to estimate the pressure around each MB. We further studied MB response via conventional ultrasound imaging and theoretical modeling. This work demonstrates a simple, scalable approach for estimating physical loads that biological cells experience during extrusion, injection, and other biofabrication processes.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107286"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145727528","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 : 2026-03-01Epub Date: 2025-12-30DOI: 10.1016/j.jmbbm.2025.107325
Junfeng Zhang , Zhanpeng Liu , Qili Sun , Ye Tian , Jing Nie , Enze Zhao , Fenbo Ma , Bin Tang , Shuaishuai Cao
Polyetheretherketone (PEEK) exhibits significant potential in orthopedic implant applications due to its elastic modulus closely resembling that of natural bone; however, its inherently bioinert surface limits the efficacy of osseointegration. Inspired by natural biomineralization processes, this study developed an innovative coating strategy based on microbially induced calcium carbonate precipitation (MICP). Through sulfonation treatment of PEEK (SPEEK), a calcium carbonate bioactive coating enriched with calcium and magnesium elements was constructed on its surface using Sporosarcina pasteurii. Characterization results revealed that the coating exhibited a microporous structure, superhydrophilicity, and a depth-dependent modulus gradient (decreasing from 6.5 GPa to 4.5 GPa) along with mechanical heterogeneity from the surface to the substrate, successfully mimicking the hierarchical mechanical architecture of native bone. In vitro cellular experiments demonstrated that SPEEK-MICP-6D significantly enhanced the proliferation, viability, and expression of osteogenesis-related genes (ALP, Runx2, Col1, BSP) in MC3T3-E1 preosteoblasts. This enhanced bioactivity was primarily attributed to the sustained release of calcium and magnesium ions from the coating, coupled with its biomimetic mechanical microenvironment. The MICP modification method offers advantages of low cost, sustainability, and scalability, providing a highly promising platform for the development of next-generation PEEK orthopedic implants that integrate biomimetic mechanical properties with enhanced bioactivity.
{"title":"Biomimetic PEEK implants with hierarchical mechanics and enhanced bioactivity","authors":"Junfeng Zhang , Zhanpeng Liu , Qili Sun , Ye Tian , Jing Nie , Enze Zhao , Fenbo Ma , Bin Tang , Shuaishuai Cao","doi":"10.1016/j.jmbbm.2025.107325","DOIUrl":"10.1016/j.jmbbm.2025.107325","url":null,"abstract":"<div><div>Polyetheretherketone (PEEK) exhibits significant potential in orthopedic implant applications due to its elastic modulus closely resembling that of natural bone; however, its inherently bioinert surface limits the efficacy of osseointegration. Inspired by natural biomineralization processes, this study developed an innovative coating strategy based on microbially induced calcium carbonate precipitation (MICP). Through sulfonation treatment of PEEK (SPEEK), a calcium carbonate bioactive coating enriched with calcium and magnesium elements was constructed on its surface using <em>Sporosarcina pasteurii.</em> Characterization results revealed that the coating exhibited a microporous structure, superhydrophilicity, and a depth-dependent modulus gradient (decreasing from 6.5 GPa to 4.5 GPa) along with mechanical heterogeneity from the surface to the substrate, successfully mimicking the hierarchical mechanical architecture of native bone. In <em>vitro</em> cellular experiments demonstrated that SPEEK-MICP-6D significantly enhanced the proliferation, viability, and expression of osteogenesis-related genes (ALP, Runx2, Col1, BSP) in MC3T3-E1 preosteoblasts. This enhanced bioactivity was primarily attributed to the sustained release of calcium and magnesium ions from the coating, coupled with its biomimetic mechanical microenvironment. The MICP modification method offers advantages of low cost, sustainability, and scalability, providing a highly promising platform for the development of next-generation PEEK orthopedic implants that integrate biomimetic mechanical properties with enhanced bioactivity.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"175 ","pages":"Article 107325"},"PeriodicalIF":3.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145914589","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}