An investigation of droplet mobility and the ultra-mild internal mechanical microenvironment in cylindrical microchannels

2021 ◽  
Vol 33 (10) ◽  
pp. 102005
Author(s):  
Mengqi Li ◽  
Zhaomiao Liu ◽  
Yan Pang ◽  
Ju Wang ◽  
Shanshan Gao ◽  
...  
Keyword(s):  
Mechanical Microenvironment

MULTI-SCALE MECHANICAL BEHAVIOR ANALYSIS ON FLUID–SOLID COUPLING FOR OSTEONS IN VARIOUS GRAVITATIONAL FIELDS

2021 ◽  
Author(s):  
HAO ZHANG ◽  
HAI-YING LIU ◽  
CHUN-QIU ZHANG ◽  
ZHEN-ZHONG LIU ◽  
WEI WANG
Keyword(s):  
Gravitational Field ◽  
Fluid Shear Stress ◽  
Bone Matrix ◽  
Fluid Pressure ◽  
Gravity Gradient ◽  
Static Compression ◽  
Gravitational Fields ◽  
Multi Scale ◽  
Earth’S Gravitational Field ◽  
Mechanical Microenvironment

Background: Compact bone mainly consists of cylindrical osteon structures. In microgravity, the change in the mechanical microenvironment of osteocytes might be the root cause of astronauts’ bone loss during space flights. Methods: A multi-scale three-dimensional (3D) fluid–solid coupling finite element model of osteons with a two-stage pore structure was developed using COMSOL software based on the natural structure of osteocytes. Gradients in gravitational fields of [Formula: see text]1, 0, 1, 2.5, and 3.7[Formula: see text]g were used to investigate the changes in the mechanical microenvironment on osteocyte structure. The difference in arteriole pulsating pressure and static compression stress caused by each gravity gradient was investigated. Results: The mechanical response of osteocytes increased with the value of g, compared with the Earth’s gravitational field. For instance, the fluid pressure of osteocytes and the von Mises stress of bone matrix near lacunae decreased by 31.3% and 99.9%, respectively, in microgravity. Under static loading, only about 16.7% of osteocytes in microgravity and 58.3% of osteocytes in the Earth’s gravitational field could reach the fluid shear stress threshold of biological reactions in cell culture experiments. Compared with the Earth’s gravitational field, the pressure gradient inside osteocytes severely decreased in microgravity. Conclusion: The mechanical microenvironment of osteocytes in microgravity might cause significant changes in the mechanical microenvironment of osteocytes, which may lead to disuse osteoporosis in astronauts.

Anchorage: Dependent Persistent Alignment of Perfused Microvasculature in Implanted Tissue Constructs

2011 ◽  
Author(s):  
Laxminarayanan Krishnan ◽  
Carlos C. Chang ◽  
Shawn Reese ◽  
Stuart K. Williams ◽  
Jeffrey A. Weiss ◽  
...  
Keyword(s):  
Local Environment ◽  
Collagen Matrix ◽  
Cell Behavior ◽  
Microvascular Networks ◽  
Tissue Constructs ◽  
Artificial Tissue ◽  
Additional Level ◽  
Mechanical Microenvironment

One of the challenges in engineering complex artificial tissue constructs, with defined matrix and cellular architecture, is the formation of a viable microcirculation within them, that inosculates with the host vasculature and matures into a functional microvascular bed. Current methods based on complex cell patterning in 2-D or 3-D matrix systems rely on ‘printing’ cells or patterns of cells on/ in a substrate, direct culture on patterned substrates, or endothelialization of decellularized vessels. We are now beginning to understand the effects of the microenvironment on microvascular constructs. Flow induced remodeling and maturation of angiogenic microvasculature and changes in functional characteristics when co-implanted with astrocyte precursors strongly suggests a role for the local environment in determining characteristics of the microvascular bed [1, 2]. Chang et al. have shown that neovascular networks from microvessels pre-aligned by direct-bioprinting in a collagen matrix, retain alignment when cultured in vitro, but lose alignment on implantation in vivo [3]. Though unloading of mechanically loaded tissue influences cell behavior [4], it does not explain this loss of orientation after implantation, of previously unloaded constructs. Implanted constructs have an additional level of complexity in the form of network revision and maturation with blood flow. We hypothesize that the local mechanical microenvironment, in addition to flow, dictates network morphology in vivo. This study compares the changes in pre-aligned microvascular networks implanted with and without anchorage.

Cell mechanical microenvironment for cell volume regulation

2019 ◽  
Vol 235 (5) ◽  
pp. 4070-4081
Author(s):  
Meng Wang ◽  
Yaowei Yang ◽  
Lichun Han ◽  
Feng Xu ◽  
Fei Li
Keyword(s):  
Cell Volume ◽  
Volume Regulation ◽  
Cell Volume Regulation ◽  
Mechanical Microenvironment

Engineering the cellular mechanical microenvironment to regulate stem cell chondrogenesis: Insights from a microgel model

2020 ◽  
Vol 113 ◽  
pp. 393-406
Author(s):  
Qi Feng ◽  
Huichang Gao ◽  
Hongji Wen ◽  
Hanhao Huang ◽  
Qingtao Li ◽  
...  
Keyword(s):  
Stem Cell ◽  
Mechanical Microenvironment
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