Shu Q. Liu^∗,†, Brandon J. Teft^*, Li-Qun Zhang^‡, Yan Chun Li^§, Yu H. Wu^*

Molecular & Cellular Biomechanics, Vol.7, No.2, pp. 59-76, 2010, DOI:10.3970/mcb.2010.007.059

Abstract The activities of vascular cells, including adhesion, proliferation, and migration, are mediated by extracellular matrix components, including collagen matrix and elastic fibers or laminae. Whereas the collagen matrix stimulates vascular cell adhesion, proliferation, and migration, the elastic laminae inhibit these activities. Coordinated regulation of cell activities by these matrix components is an essential process for controlling the development and remodeling of the vascular system. This article summarizes recent development on the role of arterial elastic laminae in regulating the development of smooth muscle-like cells from bone marrow-derived progenitor cells as well as in mediating cell adhesion, proliferation, and migration with… More >

Q Wang^*, YP Zheng^∗,†, HJ Niu^∗,‡

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 45-58, 2010, DOI:10.3970/mcb.2010.007.045

Abstract This study aims to obtain osmosis-induced swelling strains of normal and proteoglycan (PG) depleted articular cartilage using an ultrasound system and to investigate the changes in its mechanical properties due to the PG depletion using a layered triphasic model. The swelling strains of 20 cylindrical cartilage-bone samples collected from different bovine patellae were induced by decreasing the concentration of bath saline and monitored by the ultrasound system. The samples were subsequently digested by a trypsin solution for approximately 20 min to deplete proteoglycans, and the swelling behaviors of the digested samples were measured again. The bi-layered triphasic model proposed in… More >

Ning Wang^*

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 33-44, 2010, DOI:10.3970/mcb.2010.007.033

Abstract Professor Y.C. Fung has shown that living tissues remodel extensively in response to mechanical forces such as blood pressure variations. At the cellular level, those mechanical perturbations must be perceived by individual cells. However, mechanisms of mechanochemical transduction in living cells remain a central challenge to cell biologists. Contrary to predictions by existing models of living cells, we reported previously that a local stress, applied via integrin receptors, is propagated to remote sites in the cytoplasm and is concentrated at discrete foci. Here we report that these foci of strains and stresses in the cytoplasm correspond to local peak deformation… More >

W. Herzog ^∗,†, V. Joumaa*, T.R. Leonard*

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 25-32, 2010, DOI:10.3970/mcb.2010.007.025

Abstract This article has no abstract. More >

Fan Song^*

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 13-24, 2010, DOI:10.3970/mcb.2010.007.013

Abstract The electrostatic interaction effects including the interaction potential, force and torque between the neighboring chondroitin sulfate glycosaminoglycan (CS-GAG) molecular chains in the bottle brush conformation of proteoglycan aggrecan are obtained as the functions of the minimum separation distance and the mutual angle between the molecular chains based on an asymptotic solution of the Poisson-Boltzmann equation that the CS-GAGs satisfy under the normal physiological conditions of articular cartilage. The present study indicates that the electrostatic interactions are not only associated intimately with the separation distance and the mutual angle, which are shown as purely exponential in separation distance and decrease with… More >

He Gong^∗,†, Ming Zhang^‡

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 1-12, 2010, DOI:10.3970/mcb.2010.007.001

Abstract In mechanical disuse conditions associated with immobilization and microgravity in spaceflight, cortical endosteal surface moved outward with periosteal surface moving slightly or unchanged, resulting in reduction of cortical thickness. Reduced thickness of the shaft cortex of long bone can be considered as an independent predictor of fractures. Accordingly, it is important to study the remodeling process at cortical endosteal surface. This paper presents a computer simulation of cortical endosteal remodeling induced by mechanical disuse at the Basic Multicellular Units level with cortical thickness as controlling variables. The remodeling analysis was performed on a representative rectangular slice of the cross section… More >

Dilson E. Rassier^*

Molecular & Cellular Biomechanics, Vol.6, No.4, pp. 229-242, 2009, DOI:10.3970/mcb.2009.006.229

Abstract When activated skeletal muscles are stretched at slow velocities, force increases in two phases: (i) a fast increase, and (ii) a slow increase. The transition between these phases is commonly associated with the mechanical detachment of cross-bridges from actin. This phenomenon is referred to asforce enhancement during stretch. After the stretch, force decreases and reaches steady-state at levels that are higher than the force produced at the corresponding length during purely isometric contractions. This phenomenon is referred to asresidual force enhancement.The mechanisms behind the increase in force during and after stretch are still a matter of debate, and have physiological… More >

Masanori Kobayashi, Myron Spector

Molecular & Cellular Biomechanics, Vol.6, No.4, pp. 217-228, 2009, DOI:10.3970/mcb.2009.006.217

Abstract In order to achieve successful wound repair by regenerative tissue engineering using mesenchymal stem cells (MSCs), it is important to understand the response of stem cells in the scaffold matrix to mechanical stress.
To investigate the clinical effects of mechanical stress on the behavior of cells in scaffolds, bone marrow-derived mesenchymal stem cells (MSCs) were grown on a type-I collagen-glycosaminoglycan (GAG) scaffold matrix for one week under cyclic stretching loading conditions.
The porous collagen-GAG scaffold matrix for skin wound repair was prepared, the harvested canine MSCs were seeded on the scaffold, and cultured under three kinds of cyclic… More >

Kittisak Koombua^*, Ramana M. Pidaparti^∗,†,‡, P. Worth Longest^∗,‡, Kevin R. Ward^‡,§

Molecular & Cellular Biomechanics, Vol.6, No.4, pp. 203-216, 2009, DOI:10.3970/mcb.2009.006.203

Abstract Without proper knowledge of mechanical ventilation effects, physicians can aggravate an existing lung injury. A better understanding of the interaction between airflow and airway tissue during mechanical ventilation will be helpful to physicians so that they can provide appropriate ventilator parameters for intubated patients. In this study, a computational model incorporating the interactions between airflow and airway walls was developed to investigate the effects of airway tissue flexibility on airway pressure and stress. Two flow rates, 30 and 60 l/min, from mechanical ventilation were considered. The transient waveform was active inhalation with a constant flow rate and passive exhalation. Results… More >

Siva A. Vanapalli^∗,†, Yixuan Li^†, Frieder Mugele^†, Michel H. G. Duits^†

Molecular & Cellular Biomechanics, Vol.6, No.4, pp. 191-202, 2009, DOI:10.3970/mcb.2009.006.191

Abstract Endogenous granules (EGs) that consist of lipid droplets and mitochondria have been commonly used to assess intracellular mechanical properties via multiple particle tracking microrheology (MPTM). Despite their widespread use, the nature of interaction of EGs with the cytoskeletal network and the type of forces driving their dynamics - both of which are crucial for the interpretation of the results from MPTM technique - are yet to be resolved. In this report, we study the dynamics of endogenous granules in mammalian cells using particle tracking methods. We find that the ensemble dynamics of EGs is diffusive in three types of mammalian… More >