Journal of the Mechanical Behavior of Biomedical Materials最新文献

{"title":"Effects of tensile and compressive stress on bone resorption and formation parameters surrounding dental implants","authors":"Bin Li ,&nbsp;Natsuko Murakami ,&nbsp;Cangyou Xie ,&nbsp;Yuki Mouri ,&nbsp;Hitomi Matsuno ,&nbsp;Hisami Okawara ,&nbsp;Kazuhiro Aoki ,&nbsp;Noriyuki Wakabayashi","doi":"10.1016/j.jmbbm.2025.106928","DOIUrl":"10.1016/j.jmbbm.2025.106928","url":null,"abstract":"<div><div>This study investigates the effects of tensile and compressive stresses on peri-implant bone remodeling activity. Titanium implants were inserted into the extracted maxillary molar sites of four-week-old male mice and allowed to heal. A sustained load of 0.9 N, inclined at 30° from palatal to buccal, was applied for 30 min daily over 7 days. Non-loaded implants served as a controls. Non-demineralized sections parallel to the occlusal plane were prepared 150 μm below the alveolar crest, and bone morphometry parameters related to bone resorption and formation were measured within a 120 μm-wide peri-implant region, divided into distal, buccal, mesial, and palatal quarters. Stress distribution was calculated using an animal-specific three-dimensional (3D) finite element (FE) model based on microfocus CT data. In the buccal quarter, where compressive stress was statistically higher than in the other quarters, and the mesial quarter, where tensile stress was greater than that in the other quarters, bone remodeling parameters increased significantly upon loading (p &lt; 0.05), aligning with previous <em>in vivo</em> findings that mechanical stress influences bone-related cell activity. However, no significant parameter changes were observed in the distal quarter, where both tensile and compressive stresses were higher than those in the other quarters. This suggested regional suppression of remodeling activity by a simultaneous concentration of tension and compression. These findings offer crucial insights into the preservation and maintenance of the peri-implant bone under mechanical stress from occlusal forces, highlighting the role of stress distribution in bone remodeling.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"165 ","pages":"Article 106928"},"PeriodicalIF":3.3,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395820","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}

{"title":"Effect of different finishing/polishing techniques and glaze application on the flexural strength of ultratranslucent zirconia after hydrothermal aging","authors":"Sarah Emille Gomes da Silva ,&nbsp;Bianca Cristina Dantas da Silva ,&nbsp;Anne Heloyse Teixeira Crispim ,&nbsp;Amanda Maria de Oliveira Dal Piva ,&nbsp;Cornelis Johannes Kleverlaan ,&nbsp;Rodrigo Othávio de Assunção e Souza","doi":"10.1016/j.jmbbm.2025.106924","DOIUrl":"10.1016/j.jmbbm.2025.106924","url":null,"abstract":"<div><h3>Purpose</h3><div>To evaluate the effect of different finishing/polishing procedures and glaze on the surface roughness, flexure strength, and microstructure of an ultratranslucent zirconia (UZ) submitted aging.</div></div><div><h3>Methodology</h3><div>Two hundred and forty (240) UZ bars were sintered (8 × 2 × 1 mm) and treated according to the factors (n = 15): Type of finishing/polishing procedure (Control - Ctrl; Ultra-fine Diamond Burr - FG; Medium grit diamond burr- MG; Stone Bur - Stone; Rubber - Rub; FG + Rub; MG + Rub; Stone + Rub), and “Glaze” (Without and With - Gl). The bars were hydrothermally degraded (24 h, 127 °C, 1.7 bar), submitted to roughness analysis and 3-point mini flexural strength (FS) test. Scanning Electron Microscopy (SEM), X-ray Diffraction (XDR), and Weibull analysis were performed. Data were analyzed by 2-way ANOVA and Tukey test (5%).</div></div><div><h3>Results</h3><div>Finishing/Polishing’ and its interaction with ‘Glaze’ were statistically significant (P &lt; 0.0001) for FS, unlike ‘Glaze’ alone (P = 0.8827). Rub (602.11 MPa^A), Stone + Rub (555.50 MPa^AB), and Ctrl (621.72 MPa^A) showed superior FS, while FG_GL showed the lowest FS. Stone + Rub showed the highest Weibull modulus (13.15^a). Ctrl_Gl (0.18 ± 0.02^F μm) and Ctrl + Rub_Gl (0.29 ± 0.07^F μm) showed the lowest roughness. Glaze (0.48^B) reduced the roughness of the groups that did not receive it (1.56^A), with MG (2.60 ± 0.69^A μm) and FG (2.50 ± 0.7^A μm) exhibiting rougher surfaces.</div></div><div><h3>Conclusions</h3><div>Rubber polishers are ideal for minor adjustments to UZ while Stone followed by rubber is effective for greater abrasion without compromising mechanical strength. The application of glaze did not reduce mechanical strength and resulted in lower surface roughness compared to the non-glazed groups, with the exception of the FG groups.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106924"},"PeriodicalIF":3.3,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372338","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}

{"title":"Measuring full-field strain of the muscle-tendon junction using confocal microscopy combined with digital volume correlation","authors":"Nodoka Iwasaki ,&nbsp;Benjamin Morrison ,&nbsp;Aikaterina Karali ,&nbsp;Marta Roldo ,&nbsp;Gordon Blunn","doi":"10.1016/j.jmbbm.2025.106925","DOIUrl":"10.1016/j.jmbbm.2025.106925","url":null,"abstract":"<div><div>The muscle-tendon junction (MTJ) is a specialized interface that facilitates the transmission of force from the muscle to the tendon which has been implicated in muscle strains and tears. Understanding the transmission of forces and the strain generated in the MTJ is therefore important. For the first time, we report the 3D full-field strain distribution across the muscle-tendon junction (MTJ) using in-situ tensile testing and confocal microscopy coupled with digital volume correlation (DVC). This approach allowed us to measure the mechanical behaviour of the MTJ at the fibre/fascicle level. Acridine orange (AO) in 70% ethanol was used to enhance the contrast of the mouse Achilles-gastrocnemius MTJ, and the specimens were rehydrated prior to the tensile testing, which was performed using custom made tensile rig that fitted under the confocal microscopy. The 3D full-field strain distribution was obtained using DVC, where the strain changes were measured from confocal images taken with the MTJ under preload (0.4 N) and loaded (0.8 N and 1.2 N) representing 2.7- and 4-times body weight. High strain concentration was observed at the junction for both 0.8 N and 1.2 N loads. At the junction, the first principal stain (ε_p1), shear strain (γ) and von Mises strain (ε_VM) reached 15.2, 34.2 and 19.2% respectively. This study allowed us to measure fascicle level strain distribution at the MTJ. Using histology, microtears at the MTJ were seen in specimens loaded with 1.2 N which were associated with von Mises strain concentration in the adjacent region. The microtears occurred in regions where the strain level was between 8 and 15%. This study developed a methodology to determine high-resolution strain distribution at the MTJ and has the potential to be used to analyse the strain at the cellular level using higher magnification objectives.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106925"},"PeriodicalIF":3.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of paraben on uterine collagen: An integrated and targeted Correlative approach using second harmonic generation microscopy, nanoindentation, and atomic force microscopy","authors":"Mahmuda R. Arshee ,&nbsp;Ritwik Shukla ,&nbsp;Jie Li ,&nbsp;Umnia Doha ,&nbsp;Indrani C. Bagchi ,&nbsp;Ayelet Ziv-Gal ,&nbsp;Amy J. Wagoner Johnson","doi":"10.1016/j.jmbbm.2025.106926","DOIUrl":"10.1016/j.jmbbm.2025.106926","url":null,"abstract":"<div><div>This study investigates the structural and mechanical changes in uterine collagen following exposure to propylparaben (PP) using a combined methodology of Second Harmonic Generation (SHG) microscopy, Nanoindentation (NI), and Atomic Force Microscopy (AFM). SHG analysis identified significant disorganization in collagen fibril orientation in the circumferential layer and heterogeneous distribution of regions with elevated forward to backward ratios (F/B) across all uterine layers due to PP exposure. High F/B can indicate multiple potential fibril-level changes like thickened fibrils, higher crosslinking, fibril disorganization - changes not fully decipherable by SHG alone. Recognizing this limitation, the study employs NI and AFM to provide complementary mechanical and nanoscale insights. NI revealed increased indentation modulus in the exposed uteri, suggesting increased stiffness. Co-registration of the indentation response with SHG parameters uncovered that elevated F/B regions show enhanced mechanical stiffness, suggesting a fibrotic transformation following chronic PP exposure. AFM was specifically performed on regions identified by SHG as having low or high F/B, providing the necessary nanoscale resolution to elucidate the structural changes in fibrils that are likely responsible for the observed alterations. AFM confirmed the presence of disordered and entangled collagen fibrils in the circumferential layer in all regions and an increase in fibril diameter in the high F/B regions in the PP-exposed uteri. Together, these findings demonstrate significant alterations in collagen architecture due to PP exposure, revealing disruptions at both the fiber and fibril levels and highlighting the potential for broader applications of the multi-scale, multi-modal approach in collagenous tissue studies.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"165 ","pages":"Article 106926"},"PeriodicalIF":3.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Cr addition on Ti implant alloys (Ti-Cr/Ti-Al-V-Cr) to enhance corrosion and wear resistance","authors":"Maria Herbster ,&nbsp;Bernd Garke ,&nbsp;Karsten Harnisch ,&nbsp;Oliver Michael ,&nbsp;Alexandra Lieb ,&nbsp;Ulf Betke ,&nbsp;Mandy Könnecke ,&nbsp;Andreas Heyn ,&nbsp;Paulina Kriegel ,&nbsp;Henrike Thärichen ,&nbsp;Jessica Bertrand ,&nbsp;Manja Krüger ,&nbsp;Thorsten Halle","doi":"10.1016/j.jmbbm.2025.106899","DOIUrl":"10.1016/j.jmbbm.2025.106899","url":null,"abstract":"<div><div>Due to their excellent biocompatibility, favorable strength-to-weight ratio and mechanical properties, Ti-based alloys are most commonly used for long-term implants in the human body. Nevertheless, low wear resistance and increased degradation due to corrosion under critical <em>in vivo</em> conditions impair the service life of these implants. This fact opens the potential for optimization, which can be exploited by chemical alloying with Cr.</div><div>This study investigates the effect of Cr alloying on the mechanical, tribological, corrosion properties and cytocompatibility of cp Ti and TiAl6V4 alloys. Argon-arc melting was used to cast binary and quaternary specimens of varying Cr content (0.1, 0.2, 0.4, 1, 2, 4, 8, 10, 15 and 20 m%). After homogenization (1100 °C, 30 min), microstructures were characterized by means of XRD and EBSD and correlated with mechanical properties using hardness and compression tests. At up to 2 m% Cr, a martensitic α′ microstructure is formed. A Cr content of 4 m% reveals two phase α’ + β alloys. Alloying with ≥8 m% Cr results in complete β phase, whereas the significantly reduced fracture compression indicates the formation of metastable ω phase for Cr content of 8–10 m%. Based on XPS analysis, a change in the composition of the passive layers by incorporation of Cr₂O₃ and CrO_x is verified. These modified passive layers result in a reduction in corrosion current densities under mimicked severe inflammatory conditions (PBS with HCl and H₂O₂). In addition, the tribological behavior is significantly improved by a reduced wear rate for binary Ti-2/4Cr and quaternary TiAlV-4/8Cr alloys. Cell viability is not inhibited by Cr alloying, but reduced calcification is observed for all Cr modified specimens. These findings highlight the tremendous potential of Ti alloying with Cr for improved implant properties, with the alloy range of 2–4 m% Cr being the most suitable.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106899"},"PeriodicalIF":3.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A bioreactor for in vitro studies of lymphatic endothelial cells with simultaneous fluid shear stress and membrane strain","authors":"C. Davis ,&nbsp;B. Zambrano-Roman ,&nbsp;R. Sridhar ,&nbsp;A. Jastram ,&nbsp;S. Chakraborty ,&nbsp;D. Zawieja ,&nbsp;M.R. Moreno","doi":"10.1016/j.jmbbm.2025.106909","DOIUrl":"10.1016/j.jmbbm.2025.106909","url":null,"abstract":"<div><div>Reproducing the <em>in vivo</em> physiologic conditions and biomechanical environment to stimulate natural growth and behavior of lymphatic endothelial cells (LECs) is critical in studying the lymphatic system and its response to stimuli. <em>In vitro</em> studies that deconstruct the biomechanical environment, e.g. independently incorporate flow-induced shear stress or membrane strain have demonstrated the significance of mechanotransduction in LECs (and vascular endothelial cells). Such studies have facilitated the investigation of intracellular signaling pathways stimulated by a particular mechanical cue but do not accurately reproduce natural physiologic behavior of <em>in vivo</em> LECs given the absence of other natural mechanical cues. In this study, we present a novel experimental device designed to reconstruct the <em>in vivo</em> biomechanical environment, i.e. a device that enables the simultaneous application of flow-induced shear stress and cyclic stretching of LECs <em>in vitro</em>. The device is uniquely capable of simulating physiologically-relevant conditions for lymphatic endothelial cells, such as low-flow, high-strain scenarios. Using this device, we observed that, like vascular ECs, LECs aligned in the direction of fluid shear stress when steady flow was applied. In our case the behavior was observed under conditions closer to the physiological mean flow in the lymphatic vessels than vascular levels of shear stress. When concurrent cyclic stretching was applied, the alignment in the direction of flow and perpendicular to the uniaxial stretch was detected in a substantially shortened timeframe. Additionally, the distribution of alignment angles was more closely clustered around 90° under the flow/stretch scenario after 6 h than the 24 h flow only scenario, perhaps indicating a greater sensitivity to cyclic stretching than to fluid shear stress in the morphological alignment response of LECs. We also observed alignment of cell nuclei and F-actin filaments in Human Dermal Lymphatic Endothelial Cells (HDLECs) after only 6 h of combined flow and stretch. These observations underscore the importance of including both sources of mechanical stress when studying the growth and behavior of LECs.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106909"},"PeriodicalIF":3.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350113","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}

{"title":"Evaluation of boundary conditions for predicting femoral bone-implant mechanics during gait in the absence of comprehensive medical imaging","authors":"Emmanuel Eghan-Acquah ,&nbsp;Alireza Y. Bavil ,&nbsp;Laura E. Diamond ,&nbsp;Rod Barrett ,&nbsp;Christopher P. Carty ,&nbsp;Martina Barzan ,&nbsp;David Bade ,&nbsp;Azadeh Nasseri ,&nbsp;David G. Lloyd ,&nbsp;David J. Saxby ,&nbsp;Stefanie Feih","doi":"10.1016/j.jmbbm.2025.106908","DOIUrl":"10.1016/j.jmbbm.2025.106908","url":null,"abstract":"<div><div>Finite element analysis (FEA) is nowadays a pivotal tool in orthopaedic research for personalized virtual surgery planning. Despite its widespread use, a comprehensive evaluation of the effect of boundary conditions on the simulation of physiological mechanics in implanted bone is currently lacking. This study assesses the impact of boundary conditions and femur geometry on predicted femur mechanics. It focuses on an isolated implanted femur, partially imaged, from a paediatric patient with femoral varus who underwent a proximal femoral osteotomy. By employing FEA of the femur under motion with loading scenarios informed by personalized neuromusculoskeletal modelling, this study evaluated implant and bone mechanics across three femur model configurations (full-femur, proximal half-femur, and distally synthesized full-femur) with two boundary condition approaches (biomechanical and fixed distal). The biomechanical boundary condition was validated against the gold standard inertia relief method for the natural femur and thereafter exploited as the benchmark against the other implanted femur model configurations. The distally synthesized full-femur with biomechanical boundary conditions performed best and closely predicted bone-implant micromotion (R² = 0.99, nRMSE = 0.3%), risk of implant yield (&lt;1% variance from the benchmark model), and interfragmentary movement (R² = 1, nRMSE = 6%). The half-femur model with biomechanical boundary conditions overpredicted the risk of yield and interfragmentary movements by 17% and 15.8%, respectively. The fixed distal constraint method significantly overestimated the risk of implant yield in both half and synthesized full-femur models by 157% and 170%, respectively. These findings underscore the critical importance of selecting appropriate boundary conditions in the FEA of implanted femur models and advocate for the synthesis of the missing portion of the femur coupled with the biomechanical boundary conditions for more accurate predictions of bone and implant mechanics. Such insights are expected to enhance the physiological plausibility and reliability of orthopaedic research and clinical practices, especially when managing proximal femoral osteotomies.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106908"},"PeriodicalIF":3.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143328668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What does the slope of stress–stretch curves tell us about vascular tissue response?","authors":"Jia Lu ,&nbsp;Ferdinando Auricchio","doi":"10.1016/j.jmbbm.2025.106906","DOIUrl":"10.1016/j.jmbbm.2025.106906","url":null,"abstract":"<div><div>We examined a group of 50 uniaxial stress–stretch curves obtained from human ascending aortic aneurysm tissues. The curves were believed to be associated with elastic response because the stress is monotonically increasing in all curves, and so is the slope. However, 26 curves exhibit exponential-like slope while the remaining 24 curves have sigmoid slopes. We hypothesized that the slope patterns stemmed from collage waviness distribution. A structural constitutive model was introduced to describe the responses. The model employed a unimodal density function to describe the waviness distribution, from which a two-phase response ensued. In the first phase the slope is quasi-exponential, and in the second phase the slope is sigmoid. The model fitted all 50 curves perfectly well. An exponential model was also introduced for a comparison. The model fitted the curves of quasi-exponential slope generally well, but performed worse over the curves of sigmoid slope. The work suggests that the slope may encode significant information about collagen waviness, and underscores a limitation of exponential-based models.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106906"},"PeriodicalIF":3.3,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178711","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}

{"title":"Glass infiltration in an experimental ATZ ceramic composite reinforced with Al2O3 whiskers","authors":"Tiago Moreira Bastos Campos ,&nbsp;Ana Carolina da Silva ,&nbsp;Bruno Roberto Spirandeli ,&nbsp;Edmara Tatiely Pedroso Bergamo ,&nbsp;Larissa Marcia Martins Alves ,&nbsp;Ernesto Byron Benalcázar Jalkh ,&nbsp;Gilmar Patrocínio Thim ,&nbsp;Claudinei Santos ,&nbsp;Paulo G. Coelho ,&nbsp;Estevam Augusto Bonfante","doi":"10.1016/j.jmbbm.2025.106892","DOIUrl":"10.1016/j.jmbbm.2025.106892","url":null,"abstract":"<div><div>This study evaluated the development and characterization of alumina-toughened zirconia (ATZ) composites containing 10 wt% Al₂O₃ whiskers subjected to the glass infiltration. To obtain ATZ 90/10 composites, the commercial 3Y-TZP powder was mixed with synthesized alumina whiskers and subsequently compacted. Discs (n = 210) were pre-sintered at 1000 °C for 1 h. The infiltration of glass (68SiO₂-11.7Al₂O₃-3CaO-7.3Na₂O-10K₂O) was developed by mixing glass and propylene glycol, which was then applied onto ATZ pre-sintered specimens. For infiltration, the graded discs were divided into two different sintering protocols: protocol 1 (1550 °C for 2 h) and protocol 2 (1350 °C for 1 h followed by 1550 °C for 2 h). As a control group, non-infiltrated specimens were sintered using protocol 1. The specimens were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Hardness, fracture toughness, and biaxial flexural strength tests followed by fractographic analysis were performed. Statistical analyses were conducted using Weibull distribution to calculate the material's modulus (<em>m</em>) and characteristic strength (95% CI), as well as ANOVA tests. High-aspect ratio alumina whiskers (10 μm × 200 nm) were synthesized. While the control group's XRD patterns evidenced only characteristic tetragonal zirconia and α−alumina peaks, the glass-infiltrated groups did not present characteristic peaks of crystalline materials. ATZ with alumina whiskers showed higher fracture toughness and characteristic strength compared to conventional ATZ. Furthermore, glass-infiltration improved the characteristic strength of conventional ATZ with no significant differences observed in the Weibull modulus. For W-G-2, C, and W groups the fractures originated at the zirconia surface, while for C-G-1-, C-G-2, and W-G-1 the origins were inside the ceramic microstructure. In conclusion, the development of ATZ with alumina whiskers increased the biaxial flexural strength and fracture toughness compared to conventional ATZ. The glass gradation significantly improved the characteristic strength of conventional ATZ regardless of the sintering protocol used, whereas it only improved the characteristic strength of whisker-reinforced ATZ when a single sintering was performed. Additionally, the sintering protocol influenced the thickness and amount of glass gradation in the composites.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106892"},"PeriodicalIF":3.3,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178712","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}

{"title":"A bio-lattice deep learning framework for modeling discrete biological materials","authors":"Manik Kumar ,&nbsp;Nilay Upadhyay ,&nbsp;Shishir Barai ,&nbsp;Wesley F. Reinhart ,&nbsp;Christian Peco","doi":"10.1016/j.jmbbm.2025.106900","DOIUrl":"10.1016/j.jmbbm.2025.106900","url":null,"abstract":"<div><div>Biological tissues dynamically adapt their mechanical properties at the microscale in response to stimuli, often governed by discrete interacting mechanisms that dictate the material’s behavior at the macroscopic scale. An approach to model the discrete nature of these elemental units is the Lattice Spring Modeling (LSM). However, the interactions in biological matter can present a high degree of complexity and heterogeneity at the macroscale, posing a computational challenge in multiscale modeling. In this work, we propose a novel machine learning-based multiscale framework that integrates deep neural networks (DNNs), the finite element method (FEM), and a LSM-inspired microstructure description to investigate the behavior of discrete, spatially heterogeneous materials. We develop a versatile, assumption-free lattice framework for interacting discrete units, and derive a consistent multiscale connection with our FEM implementation. A single DNN is trained to learn the constitutive equations of various particle configurations and boundary conditions, enabling rapid response predictions of heterogeneous biological tissues. We demonstrate the effectiveness of our approach with extensive testing, starting with benchmark cases and progressively increasing the complexity of the microstructures. We explored materials ranging from soft to hard inclusions, then combined them to form a macroscopically homogeneous material, a gradient-varying polycrystalline solid, and fully randomized configurations. Our results show that the model accurately captures the material response across these spatially varying structures.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"164 ","pages":"Article 106900"},"PeriodicalIF":3.3,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143076794","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}