Evaluation of the phenotypic properties of cardiac cells cultured in micropatterns

Author(s)

Jennifer Adriane dos Santos

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2023-04-19

Examining board members

Adriano Mesquita Alencar; Jonatas Bussador do Amaral; Anderson Zanardi de Freitas; Francisco Rafael Martins Laurindo

• Advisor: Adriano Mesquita Alencar

Abstract

Among the various problems considered when studying the rheological properties of living cells, we can mention the mechanical characterization and response of cardiac cells, in particular, cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs), a topic with strong scientific appeal and few papers found in the literature. It is known that the active regulation of cellular forces during adhesion plays an important role in determining the size, shape, and internal structure of cells. To this end, a general application protocol was created, where tensile force measurements were performed using rheological techniques such as Traction Force Microscopy (TFM) and the application of electrical stimulation (EE) to synchronize the contraction of the adhered hiPSC-CMs on micropatterns (MPs), which consists of a method of producing microscopic patterns for the confinement of cells, to understand the functional mechanisms in which the cell behaves and responds to the surrounding microenvironment. To this end, we used polyacrylamide substrates where Geltrex (GTX) and Laminin (LAM) micropatterns were produced and incorporated through a Polydimethylsiloxane (PDMS) mold to characterize the effect of these stimuli applied to hiPSC-CMs to evaluate the mechanics of the cell phenotype by determining the tensile strength properties, contraction power and morphology of these cells. In this study, a total of 72 cells divided into 8 groups were studied as follows: (1) cells cultured in MPs using LAM matrix; (2) cultured in MPs using GTX; (3) cultured in LAM without MPs; (4) cultured in GTX without MPs. In addition, the electrical stimulator was used in each group, making a total of 8 groups studied. The use of MPs caused an increase in the degree of alignment of hiPSC-CMs and after applying the electrical stimuli the mean quadratic traction of hiPSC-CMs decreased in 87 % of the analyzed cells (AU)

• FAPESP's process: 18/20910-5 - Evaluation of Phenotypic Properties of Micropatterned Cardiac Cells
• Grantee: Jennifer Adriane dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate