Qingyu Wang¹, Dalin Tang^1,2,*, Gador Canton³, Zheyang Wu², Thomas S. Hatsukami⁴, Kristen L. Billiar⁵, Chun Yuan⁶

Molecular & Cellular Biomechanics, Vol.15, No.4, pp. 189-201, 2018, DOI:10.32604/mcb.2018.04572

Abstract Cardiovascular diseases are closely linked to atherosclerotic plaque development and rupture. Assessment of plaque vulnerability is of fundamental significance to cardiovascular research and disease diagnosis, prevention, treatment and management. Magnetic resonance image (MRI) data of carotid atherosclerotic plaques from 8 patients (5 male, 3 female; age: 62-83, mean=71) were acquired at the University of Washington (UW), Seattle by the Vascular Imaging Laboratory (VIL) with written informed consent obtained. Patient-specific vessel material properties were quantified using Cine MRI data for modeling use. 3D thin-layer models were used to obtain plaque stress and strain for plaque assessment. A stress-based plaque vulnerability index… More >

Ruihan Zhang^1,2, Junhao Yang¹, Chunxiao Chen^1,*

Molecular & Cellular Biomechanics, Vol.15, No.3, pp. 177-187, 2018, DOI: 10.3970/mcb.2018.04292

Abstract The proportion of cells staining for the nuclear antigen Ki-67 is an important predictive indicator for assessment of tumor cell proliferation and growth in routine pathological investigation. Instead of traditional scoring methods based on the experience of a trained laboratory scientist, deep learning approach can be automatically used to analyze the expression of Ki-67 as well. Deep learning based on convolutional neural networks (CNN) for image classification and single shot multibox detector (SSD) for object detection are used to investigate the expression of Ki-67 for assessment of biopsies from patients with breast cancer in this study. The results focus on… More >

Ying Mao¹, Chaojing Li¹, Peng Ge¹, Fujun Wang^1,*, Lu Wang^1,*

Molecular & Cellular Biomechanics, Vol.15, No.3, pp. 143-154, 2018, DOI: 10.3970/mcb.2018.03987

Abstract Heparin/ PEG-PCL core-shell microcarriers were fabricated in one-step via coaxial-electrospraying technology. Optimization of the coaxial-electrospraying processing is by controlling the PEG-PCL concentration, applied voltage, receiving distance, and feed rate. The influence of the electrospray parameters on microsphere morphology was studied by optical microscopy and scanning electron microscopy. The functional groups and components of the electrosprayed microspheres were characterized by Fourier transform infrared spectroscopy (FTIR). Transmission electron microscope (TEM) observation proved the core-shell structure of heparin-loaded PEG-PCL microspheres. Drug loading and releasing study demonstrated that PEG-PCL concentration could control the encapsulation efficiency and releasing activity of the heparin in the microspheres.… More >

JongWon Kim^1,2, Ning Li², Ramana Pidaparti^2,*, Xianqiao Wang^2,*

Molecular & Cellular Biomechanics, Vol.15, No.3, pp. 127-141, 2018, DOI: 10.3970/mcb.2018.02669

Abstract Nonlinear microstructure of the microtubules (MTs) plays an important role in their mechanical properties. Despite the extensive efforts into the development of continuum models for microtubules, a mesoscale finite element model that can link the molecular level information to the overall performance of microtubules is still missing. The aim of this study is to develop a molecular dynamics model (MDM), finite element model (FEM) and structural mechanics beam model (SMBM) for tubulins of protofilament (PF). In MDM, the backbone atoms of α-tubulin were fixed while the backbone atoms of β-tubulin were attached to a molecular dynamics (MD) atom through a… More >

Yuxiang Huang¹, Chuliu He¹, Jiaqiu Wang², Yuehong Miao¹, Tongjin Zhu¹, Ping Zhou¹, Zhiyong Li^1,2,*

Molecular & Cellular Biomechanics, Vol.15, No.2, pp. 117-125, 2018, DOI: 10.3970/mcb.2018.02478

Abstract Intravascular optical coherence tomography (IVOCT) is becoming more and more popular in clinical diagnosis of coronary atherosclerotic. However, reading IVOCT images is of large amount of work. This article describes a method based on image feature extraction and support vector machine (SVM) to achieve semi-automatic segmentation of IVOCT images. The image features utilized in this work including light attenuation coefficients and image textures based on gray level co-occurrence matrix. Different sets of hyper-parameters and image features were tested. This method achieved an accuracy of 83% on the test images. Single class accuracy of 89% for fibrous, 79.3% for calcification and… More >

Zhedian Zhou¹, Tal Geva², Rahul H. Rathod², Alexander Tang², Chun Yang³, Kristen L. Billiar⁴, Dalin Tang^1,*,3, Pedro del Nido⁵

Molecular & Cellular Biomechanics, Vol.15, No.2, pp. 99-115, 2018, DOI: 10.3970/mcb.2018.00558

Abstract Patients with repaired Tetralogy of Fallot (ToF), a congenital heart defect which includes a ventricular septal defect and severe right ventricular outflow obstruction, account for the majority of cases with late onset right ventricle (RV) failure. The current surgical approach, which includes pulmonary valve replacement/insertion (PVR), has yielded mixed results. A computational parametric study using 7 patient-specific RV/LV models based on cardiac magnetic resonance (CMR) data as "virtual surgery" was performed to investigate the impact of patch size, RV remodeling and tissue regeneration in PVR surgery design on RV cardiac functions. Two patch sizes, three degrees of scar trimming (RV… More >

Lilan Gao^1,2,*, Qingxian Yuan^1,2, Ruixin Li^3,*, Lei Chen^1,2, Chunqiu Zhang^1,2, Xizheng Zhang^1,2

Molecular & Cellular Biomechanics, Vol.15, No.2, pp. 85-98, 2018, DOI: 10.3970/mcb.2018.00329

Abstract Silk fibroin-typeⅡcollagen scaffold was made by 3D printing technique and freeze-drying method, and its mechanical properties were studied by experiments and theoretical prediction. The results show that the three-dimensional silk fibroin-typeⅡ collagen scaffold has good porosity and water absorption, which is (89.3%+3.26%) and (824.09%+93.05%), respectively. With the given strain value, the stress of scaffold decreases rapidly firstly and then tends to be stable during the stress relaxation. Both initial and instantaneous stresses increase with increase of applied strain value. The creep strains of scaffold with different stress levels show the two stages: the rapidly increasing stage and the second stable… More >

Jiangguo Lin¹, Botao Xiao^1,2, Quhuan Li¹, Ying Fang¹, Jianhua Wu^1,*

Molecular & Cellular Biomechanics, Vol.15, No.1, pp. 37-49, 2018, DOI:10.3970/mcb.2018.015.037

Abstract The protein structure-function paradigm implies that the structure of a protein defines its function. Crystallization techniques such as X-ray, electron microscopy (EM) and nuclear magnetic resonance (NMR) have been applied to resolve the crystal structure of numerous proteins, provided beautiful and informative models of proteins. However, proteins are not intrinsically in static state but in dynamic state, which is lack in crystal models. The protein flexibility, a key mechanical property of proteins, plays important roles in various biological processes, such as ligand-receptor interaction, signaling transduction, substrate recognition and post-translational modifications. Advanced time-resolved crystallography has been developed recent years to visualize… More >

Virginia Aragon Sanabria¹, Cheng Dong^*

Molecular & Cellular Biomechanics, Vol.15, No.1, pp. 1-19, 2018, DOI:10.3970/mcb.2018.015.001

Abstract Endothelial barrier function is critical for tissue homeostasis throughout the body. Disruption of the endothelial monolayer leads to edema, vascular diseases and even cancer metastasis among other pathological conditions. Breakdown of the endothelial barrier integrity triggered by cytokines (e.g.IL-8,IL-1β) and growth factors (e.g.VEGF) is well documented. However, endothelial cells are subject to major biomechanical forces that affect their behavior. Due to their unique location at the interface between circulating blood and surrounding tissues, endothelial cells experience shear stress, strain and contraction forces. More than three decades ago, it was already appreciated that shear flow caused endothelial cells alignment in the… More >

Yang Li¹, Xiuxian Liu², Zhiyong Li^2,*, Jiayi Tong¹, Yi Feng¹, Genshan Ma¹, Chengxing Shen³, Naifeng Liu¹

Molecular & Cellular Biomechanics, Vol.14, No.4, pp. 213-229, 2017, DOI:10.3970/mcb.2017.014.213

Abstract Coronary tortuosity is a common angiographic finding, but the hemodynamic significance of coronary tortuosity is largely unknown. The impact of coronary tortuosity on coronary pressure and wall shear stress is still unclear. We addressed this issue in the present experimental study. A distorted tube model connected to heart pumping machine was established to simulate the coronary circulation. The pressure of each point was measured with a coronary pressure guidewire. Influence of tortuosity angle and tortuosity number on local pressure was measured. Wall shear stress was calculated accordingly to the pressure of each point. Pressure distribution in this system was affected… More >