Biology subjects

DePalma, S. J.

Publications and source records attributed to DePalma, S. J..

2 recordsLinked to original sources

bioRxiv2021

Mechanical intercellular communication via matrix-borne cell force transmission during vascular network formation

Intercellular communication is critical to the development and homeostatic function of all tissues. Previous work has shown that cells can communicate mechanically via transmission of cell-generated forces through their surrounding extracellular matrix, but this process is not well understood. Here, we utilized synthetic, electrospun fibrous matrices in conjunction with a microfabrication-based cell patterning approach to examine mechanical intercellular communication (MIC) between endothelial cells (ECs) during the assembly of microvascular networks. We found that cell force-mediated matrix displacements in deformable fibrous matrices underly directional migration of neighboring ECs towards each other prior to the formation of stable cell-cell connections. We also identified a critical role for intracellular calcium signaling mediated by focal adhesion kinase and TRPV4 during MIC that extends to multicellular assembly of vessel-like networks in 3D fibrin hydrogels. The results presented here are critical to the design of biomaterials that support cellular self-assembly for tissue engineering applications.

bioengineering↗

bioRxiv2021

Biomechanics and Myofibrillar Alignment Enhance Contractile Development and Reproducibility in Stem Cell Derived Cardiac Muscle

Human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) allow novel investigations of human cardiac disease, but disorganized mechanics and immaturity of hPSC-CMs on two-dimensional (2D) surfaces have been hurdles for efficient and reproducible study of these cells. Here, we developed a platform of micron-scale 2D cardiac tissues (M2DCTs) to precisely control biomechanics in arrays of thousands of purified, independently contracting cardiac muscle strips in 2D. By defining geometry and workload in M2DCTs in this reductionist platform that does not incorporate other cell types, we show that myofibrillar alignment and auxotonic contractions at physiologic workload critically drive maturation of cardiac contractile function, calcium handling, and electrophysiology. Additionally, the organized biomechanics in this system facilitates rapid and automated extraction of contractile kinetic parameters from brightfield microscopy images, increasing the reproducibility and throughput of pharmacologic testing. Finally, we show that M2DCTs enable precise and efficient dissection of contractile kinetics in cardiomyopathy disease models.

cell biology↗