traction-microscopy-integrated-with-microfluidics-for-chemotactic

Traction Microscopy Integrated with Microfluidics for Chemotactic Collective Migration

Cells change migration patterns in response to chemical stimuli, including the gradients of the stimuli. Cellular migration in the direction of a chemical ...

The interplay between neurogenesis and angiogenesis is crucial during the development mediated by neuro-angiogenic morphogens. In particular, the angiogenic activity of neuropeptides and their role in tissue regeneration have long been investigated for better understanding of their biological mechanisms and further applications. However, there have been few studies for direct comparison of angiogenic activities of neuropeptides for  and  models. In this study, we report that direct comparison of the angiogenic activities of neuropeptide Y, secretoneurin, and substance P (SP) immobilized on hydrogels in  and  experiments.

Comparison of Angiogenic Activities of Three Neuropeptides, Substance P, Secretoneurin, and Neuropeptide Y Using Myocardial Infarction.

Collective cellular migration plays a central role in development, regeneration, and metastasis. In these processes, mechanical interactions between cells are fundamental but measurement of these interactions is often hampered by technical limitations. To overcome some of these limitations, here we describe a system that integrates microfluidics with traction microscopy (TM). Using this system we can measure simultaneously, and in real time, migration speeds, tractions, and intercellular tension throughout an island of confluent Madin-Darby canine kidney (MDCK) cells. The cell island is exposed to hepatocyte growth factor (HGF) at a controlled gradient of concentrations; HGF is known to elicit epithelial-to-mesenchymal transition (EMT) and cell scattering. As expected, the rate of expansion of the cell island was dependent on the concentration of HGF. Higher concentrations of HGF reduced intercellular tensions, as expected during EMT. A novel finding, however, is that the effects of HGF concentration and its gradient were seen within an island. This integrated experimental system thus provides an integrated tool to better understand cellular forces during collective cellular migration under chemical gradients.

Traction microscopy with integrated microfluidics: responses of the multi-cellular island to gradients of HGF.

In vitro maturation of cardiomyocytes in 3D is essential for the development of viable cardiac models for therapeutic and developmental studies. The method by which cardiomyocytes undergoes maturation has significant implications for understanding cardiomyocytes biology. The regulation of the extracellular matrix (ECM) by changing the composition and stiffness is quintessential for engineering a suitable environment for cardiomyocytes maturation. In this paper, we demonstrate that collagen type I, a component of the ECM, plays a crucial role in the maturation of cardiomyocytes. To this end, embryonic stem-cell derived cardiomyocytes were incorporated into Matrigel-based hydrogels with varying collagen type I concentrations of 0 mg, 3 mg, and 6 mg. Each hydrogel was analyzed by measuring the degree of stiffness, the expression levels of MLC2v, TBX18, and pre-miR-21, and the size of the hydrogels. It was shown that among the hydrogel variants, the Matrigel-based hydrogel with 3 mg of collagen type I facilitates cardiomyocyte maturation by increasing MLC2v expression. The treatment of transforming growth factor β1 (TGF-β1) or fibroblast growth factor 4 (FGF-4) on the hydrogels further enhanced the MLC2v expression and thereby cardiomyocyte maturation.

Article	Year
Comparison of Angiogenic Activities of Three Neuropeptides, Substance P, Secretoneurin, and Neuropeptide Y Using Myocardial Infarction. Tissue engineering and regenerative medicine\| PubMed ID: 30603572	2018
Traction microscopy with integrated microfluidics: responses of the multi-cellular island to gradients of HGF. Lab on a chip\| PubMed ID: 30924490	2019
Collagen Type I Containing Hybrid Hydrogel Enhances Cardiomyocyte Maturation in a 3D Cardiac Model. Polymers\| PubMed ID: 30995718	2019

Jongseong Kim

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