{"title":"Numerical study of the structural design influence on cartilage cell differentiation in mechanically stimulated hydrogel scaffolds using an FSI-based model.","authors":"Pedram Azizi, Christoph Drobek, Hermann Seitz","doi":"10.1007/s10237-025-01976-1","DOIUrl":"10.1007/s10237-025-01976-1","url":null,"abstract":"<p><p>Three-dimensional (3D) hydrogel scaffolds show considerable promise for the regenerative treatment of cartilage and bone defects. Within tissue engineering, these scaffolds can be mechanically stimulated to specifically promote cartilage formation. While in vitro experiments are traditionally used to study the influence of scaffold structure on cell differentiation, in silico studies offer a complementary, cost-effective, and powerful approach. This numerical study employs a transient fluid-structure interaction (FSI) model to modify the structural design of a mechanically stimulated hydrogel scaffold for enhanced cartilage cell differentiation. The study involved two key modification steps applied to scaffolds under 5% compression. In the first step, scaffold porosity was adjusted by altering the number of strands per layer. The scaffold designed with 38% porosity, consisting of 9 strands per layer across 9 layers, improved cartilage differentiation by approximately 15%. The second step focused on scaling the selected scaffold from step 1 by adjusting the number of layers while keeping the porosity constant, aiming to optimize pore dimensions. This led to a slight improvement in cartilage differentiation of about 2.3%. The results indicate that porosity exerts a more significant influence on cell differentiation than pore size in the structured scaffolds investigated. The FSI-based model demonstrates strong potential for analyzing the impact of pore architecture on cell differentiation, although manufacturing challenges of hydrogel scaffolds may limit the practical application of these modification strategies.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1417-1433"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12246015/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The impact of coronary outflow and non-Newtonian fluid property on aortic valve haemodynamics.","authors":"Zhongjie Yin, Chlöe Armour, Harkamaljot Kandail, Declan P O'Regan, Toufan Bahrami, Saeed Mirsadraee, Selene Pirola, Xiao Yun Xu","doi":"10.1007/s10237-025-01975-2","DOIUrl":"10.1007/s10237-025-01975-2","url":null,"abstract":"<p><p>The normal healthy aortic valve (AoV) has three leaflets, two of which have outflows to the coronary arteries. Blood flow through the coronary ostia will have an impact on AoV dynamics and the surrounding haemodynamics, leading to differential shear stress distributions at the aortic side of the three leaflets. In addition, aortic root haemodynamics may also be influenced by the non-Newtonian behaviour of blood which is known as a shear-thinning fluid due to the aggregation of red blood cells at low shear rate. However, the combined effect of coronary and non-Newtonian flow on AoV haemodynamics has not been studied in an anatomically realistic setting. In this study, strongly coupled fluid-structure interaction (FSI) analyses were performed on a natural, healthy AoV, with and without accounting for coronary outflows and non-Newtonian properties of blood. Our results showed that the influence of coronary outflow is more pronounced than employing a non-Newtonian model, and their combined effect is non-negligible, particularly on wall shear stress. Incorporating coronary outflow and non-Newtonian properties increased time-averaged wall shear stress (TAWSS) in the aortic sinus by up to 108.45%; it also increased TAWSS on the aortic side of valve leaflets by 41.04%, 44.76%, and 54.91% on the left, right and non-coronary leaflet, respectively. These results highlight the importance of incorporating coronary outflow and non-Newtonian properties when accurate predictions of wall shear stress and its related parameters are critical.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1401-1416"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12245955/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144293162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of the transjugular intrahepatic portosystemic shunt (TIPS) surgical strategies: a computational fluid dynamics perspective.","authors":"Baopeng Wu, Hao Han, Jing Yao, Lingyu Jiang, Jian Yang, Ying Xin, Runxin Fang, Lingling Wei, Shicheng He, Zhiyong Li, Qiang Chen","doi":"10.1007/s10237-025-01970-7","DOIUrl":"10.1007/s10237-025-01970-7","url":null,"abstract":"<p><p>Transjugular intrahepatic portosystemic shunt (TIPS) surgery is commonly employed to treat the portal hypertension (PH), and an appropriate surgical strategy is crucial to balance the surgical outcome and post-TIPS complications. This study numerically explored the effects of six TIPS surgical strategies on the shunt outcome and PV stenosis risk by considering three stent insertion positions with two in-vessel covered lengths from the perspective of the hemodynamics. Sequential CT images of 21 PH subjects were used to reconstruct the six kinds of virtual TIPS surgical models with 6 mm stent and further to compare their five post-TIPS hemodynamic indexes. According to four of the five indexes, it was found that although there was no significant difference between the six surgical strategies, the stent insertion into the main portal vein (MPV) with in-vessel covered length 0 cm was slightly better to reduce the PV pressure, improve the shunt outcome, and potentially decrease the post-TIPS PV stenosis risk. The current findings could be helpful for clinical applications in the aspect of selecting TIPS surgical strategy to treat the PH.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1327-1341"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hemodynamic differences and endoleak risk assessment of different angles of chimney stent graft deployment in chimney technique using integrated structural and fluid dynamics simulation.","authors":"Xiao Han, Jing Zhu, Yue Che, Xiran Cao, Mingyu Wan, Xinhui Si, Wei Wang, Chang Shu, Mingyao Luo, Xuelan Zhang","doi":"10.1007/s10237-025-01964-5","DOIUrl":"10.1007/s10237-025-01964-5","url":null,"abstract":"<p><p>Chimney technique is an effective method for guaranteeing left subclavian artery (LSA) revascularization for patients receiving thoracic endovascular aortic repair. However, the complications like endoleak often occur after the chimney technique, and clinical studies have shown that they are closely related to the configuration of the chimney stent graft (SG). In this paper, we simulated the deployment of chimney SG with different angles and thoracic aortic SG, and analyzed the risk of complications according to numerical simulation results. Thoracic aortic SG and chimney SGs with different angles were designed based on patient-specific aortic geometry. The dynamic deployment process of SGs was simulated, followed by computational fluid dynamics (CFD) analysis to evaluate hemodynamic differences. Results indicate that the angle of chimney SG has little influence on the von Mises stress on the vascular wall. The endoleak flow rate at peak systole reached 11.15 ml/s in the 70° configuration, which is 1.80 times that of the 45° configuration. Meanwhile, the flow rate of LSA reached 5.94 ml/s in the 45° configuration, which is 1.21 times that of the 70° configuration. This indicates that the 45° configuration may reduce the risk of endoleak and flow obstruction to LSA. In addition, the relative residence time of 0° or 15° configuration is larger, suggesting a higher risk of thrombosis. This study employs virtual stent deployment and CFD analysis to predict the risk of complications associated with the deployment of chimney stents with different angles, potentially aiding surgeons in selecting the most appropriate surgical plan.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1251-1266"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joonas P Kosonen, Atte S A Eskelinen, Gustavo A Orozco, Mitchell C Coleman, Jessica E Goetz, Donald D Anderson, Alan J Grodzinsky, Petri Tanska, Rami K Korhonen
{"title":"Mechanobiochemical finite element model to analyze impact-loading-induced cell damage, subsequent proteoglycan loss, and anti-oxidative treatment effects in articular cartilage.","authors":"Joonas P Kosonen, Atte S A Eskelinen, Gustavo A Orozco, Mitchell C Coleman, Jessica E Goetz, Donald D Anderson, Alan J Grodzinsky, Petri Tanska, Rami K Korhonen","doi":"10.1007/s10237-025-01961-8","DOIUrl":"10.1007/s10237-025-01961-8","url":null,"abstract":"<p><p>Joint trauma often leads to articular cartilage degeneration and post-traumatic osteoarthritis (PTOA). Pivotal determinants include trauma-induced excessive tissue strains that damage cartilage cells. As a downstream effect, these damaged cells can trigger cartilage degeneration via oxidative stress, cell death, and proteolytic tissue degeneration. N-acetylcysteine (NAC) has emerged as an antioxidant capable of inhibiting oxidative stress, cell death, and cartilage degeneration post-impact. However, the temporal effects of NAC are not fully understood and remain difficult to assess solely by physical experiments. Thus, we developed a computational finite element analysis framework to simulate a drop-tower impact of cartilage in Abaqus, and subsequent oxidative stress-related cell damage, and NAC treatment upon cartilage proteoglycan content in Comsol Multiphysics, based on prior ex vivo experiments. Model results provide evidence that immediate NAC treatment can reduce proteoglycan loss by mitigating oxidative stress, cell death (improved proteoglycan biosynthesis), and enzymatic proteoglycan depletion. Our simulations also indicate that delayed NAC treatment may not inhibit cartilage proteoglycan loss despite reduced cell death after impact. These results enhance understanding of the temporal effects of impact-related cell damage and treatment that are critical for the development of effective treatments for PTOA. In the future, our modeling framework could increase understanding of time-dependent mechanisms of oxidative stress and downstream effects in injured cartilage and aid in developing better treatments to mitigate PTOA progression.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1191-1206"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12246027/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144053753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francesca Renzi, Giovanni Puppini, Giovanni B Luciani, Christian Vergara
{"title":"Image-based computational hemodynamics in the right heart.","authors":"Francesca Renzi, Giovanni Puppini, Giovanni B Luciani, Christian Vergara","doi":"10.1007/s10237-025-01963-6","DOIUrl":"10.1007/s10237-025-01963-6","url":null,"abstract":"<p><p>Characterizing flow within the right heart (RH) is particularly challenging due to its complex geometries. However, gaining insight into RH fluid dynamics is of extreme diagnostic importance, given the high prevalence of acquired and congenital heart diseases with impaired RH function. In this proof-of-concept study, we propose a pipeline for patient-specific simulations of RH hemodynamics. We reconstruct the geometry and motion of the patient's right atrium, ventricle, and pulmonary and tricuspid valves, from multi-series cine MRI. For this purpose, we develop a novel and flexible reconstruction procedure that, for the first time, integrates patient-specific tricuspid valve dynamics into a computational model, enhancing the accuracy of our RH blood flow simulations. We apply this approach to study the hemodynamics in both healthy and repaired-ToF RH with severe pulmonary regurgitation, as well as to assess the hemodynamic changes induced by the pulmonary valve replacement intervention. Modeling the entire RH enables us to understand the contribution of the superior and inferior vena cava inflows to the ventricular filling, as well as the impact of the impaired right atrial function on the ventricular diastole. To analyze the turbulent and transitional behavior, we include the large eddy simulation sigma model in our computational framework, which reveals how the contribution of the smallest scales in the dissipation of the turbulent energy changes among health and disease.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1223-1250"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144265006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Biomorphoelasticity alone: limitations in modeling post-burn contraction and hypertrophy without finite strains.","authors":"Ginger Egberts, Fred Vermolen, Paul van Zuijlen","doi":"10.1007/s10237-025-01969-0","DOIUrl":"10.1007/s10237-025-01969-0","url":null,"abstract":"<p><p>We present a continuum hypothesis-based two-dimensional biomorphoelastic model describing post-burn scar hypertrophy and contraction. The model is based on morphoelasticity for permanent deformations and combined with a chemical-biological model that incorporates cellular densities, collagen density, and the concentration of chemoattractants. We perform a sensitivity analysis for the independent parameters of the model and focus on the effects on the features of the post-burn dermal thickness given a low myofibroblast apoptosis rate. We conclude that the most sensitive parameters are the equilibrium collagen concentration, the signaling molecule secretion rate and the cell force constant, and link these results to stability constraints. Next, we observe a relationship between the simulated contraction and hypertrophy and show the effects for significant variations in the myofibroblast apoptosis rate (high/low). Our ultimate goal is to optimize post-burn treatments, by developing models that predict with a high degree of certainty. We consider the presented model and sensitivity analysis to be a step toward their construction.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1313-1326"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12246031/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of the biomechanical effects of severe anterior disc displacement on the temporomandibular joint and occlusion.","authors":"Chunxin Yang, Tinghui Sun, Bingmei Shao, Zhan Liu","doi":"10.1007/s10237-025-01965-4","DOIUrl":"10.1007/s10237-025-01965-4","url":null,"abstract":"<p><p>The temporomandibular joint (TMJ) and occlusion, as critical load-bearing components of the stomatognathic system, exhibit complex interdependence. While occlusal abnormalities contribute to internal joint disorders, their reciprocal effects remain poorly understood. This study investigates how severe anterior disc displacement (ADD) alters the stress distribution within the TMJ and the occlusion, aiming to elucidate the TMJ-occlusion relationship and inform clinical diagnosis and treatment strategies. Refined finite element models of the masticatory system of the normal, bilaterally severe ADD, and unilaterally severe ADD groups were developed. Stress distributions were analyzed under maximum voluntary intercuspal clenching (MIC) and maximum voluntary unilateral molar clenching (MUC) with corresponding muscle force intensities. Results showed that under high-intensity clenching, the contact stress on the second molars in the severe ADD groups (48.4-50.3 MPa) exceeded that in the normal group (37.7-38.4 MPa). The condylar contact stress of the severe ADD group was more than 40 times greater than that of the normal group. The ranking of peak stresses on the condyles with unilateral severe ADD under different high-intensity tasks was as follows: MUCI (336.97 MPa) > MUCC (206.54 MPa) > MIC (169.19 MPa). In conclusion, severe ADD under high-intensity clenching induces anterior slippage of discs, resulting in abnormal stress concentrations on the condyles and second molars, particularly during ipsilateral clenching. To mitigate potential biomechanical risks, patients are encouraged to adopt balanced mastication habits.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":"1267-1277"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144126167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marisa S Bazzi, Hadi Wiputra, Weihua Guan, Victor H Barocas
{"title":"Ascending aortic aneurysm growth in the Fbln4<sup>SMKO</sup> mouse is consistent with uniform growth laws.","authors":"Marisa S Bazzi, Hadi Wiputra, Weihua Guan, Victor H Barocas","doi":"10.1007/s10237-025-01972-5","DOIUrl":"https://doi.org/10.1007/s10237-025-01972-5","url":null,"abstract":"<p><p>Arterial growth and remodeling (G&R), in response to biomechanical stimuli, plays a pivotal role in vascular health. Disruptions in G&R, often seen in conditions such as aneurysms and atherosclerosis, can lead to pathological changes and pose significant health risks. Assessing risk should not only consider the current state of the aneurysm but also how it develops over the subsequent months. Herein, we make a controlled, subject-specific assessment of maladaptive aortic tissue growth using data previously obtained for the Fbln4<sup>SMKO</sup> mouse model. The computational model uses a locally applied continuum G&R approach coupled with fluid-structure interaction (FSI) simulations. Ten mice were studied, exhibiting varying degrees of aneurysm formation over time. This investigation focused on the ascending aorta, where aneurysms develop in the Fbln4<sup>SMKO</sup> mouse. A continuous G&R model was tuned and evaluated using information from 2, 4, and 6 months obtained from CT scans. A G&R model with uniform growth laws showed variable accuracy in predicting circumferential growth across different mice, exhibiting both under- and over-estimations compared to in vivo measurements. Modeling prediction showed to be improved by multiple-domain modeling. There is correlation between (1) the fitted circumferential growth time constants and the observed ascending aorta Young's modulus and (2) the fitted axial growth time constant and the tortuosity index. Furthermore, the ratio of the circumferential growth time constant to the circumferential stress correlated with mouse lifespan more strongly than diameter change, suggesting that analysis of a G&R model may be valuable in predicting risk of aneurysm rupture.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144673663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tension-area relationship in compartmentalized crumpled plasma membrane: a mechanistic model and its implications.","authors":"Andrey K Tsaturyan","doi":"10.1007/s10237-025-01992-1","DOIUrl":"https://doi.org/10.1007/s10237-025-01992-1","url":null,"abstract":"<p><p>The plasma membrane is a liquid lipid bilayer containing both dissolved proteins and proteins anchoring the membrane to the underlying actin cortex. Membrane tension, a 2D analog of pressure in a 3D liquid, is believed to play a crucial role in organizing essential processes within cells and tissues. This, along with recent, conflicting data on the speed of membrane tension propagation, highlights the need for a comprehensive mechanical model to describe tension in the cortex-anchored plasma membrane as a function of transmembrane hydrostatic pressure difference and excess membrane area due to cortex contraction. In this study, we present a mechanical model of plasma membrane compartments, separated by \"picket fences\" of cortex-anchoring proteins permeable to lipids. Beyond hydrostatic pressure, the model incorporates the 2D osmotic pressure exerted by membrane-dissolved proteins. Our findings reveal that the tension-area relationship within a membrane compartment exhibits a seemingly paradoxical feature: in a specific range of membrane surface area, an increase in area leads to a rise in tension. We further model the tension-area relationship for an ensemble of membrane compartments, which exchange membrane area through shared borders, and discuss potential biological implications of this model.</p>","PeriodicalId":489,"journal":{"name":"Biomechanics and Modeling in Mechanobiology","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144658005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}