Generating affordable and more representative cardiotoxicity testing platforms is a must to increase public confidence in drugs simultaneous to solid economic growth. We aim to use micro-contact printing (μCP)-based "Single Cell Adhesion Dot Arrays" SCADA substrates with human cardiovascular phenotypes to develop a low-cost, high-throughput and easy-to-use system for human cardiotoxicity tracking.
We use small molecule-based differentiation protocols to obtain highly-pure cardiomyocytes (hiPSC-CMs) and smooth muscle cells (hiPSC-SMCs), as defined by FACS, IF and RT-qPCR for specific markers. Micropatterned SCADAs were tuned to match the specific biological requirements of these cells. Hence, geometry, size and distribution of protein patterns in combination with diverse cell density plating conditions, drove for 45x25µm Matrigel rectangular dots as the best design for hiPSC-CMs while collagen type I rectangular dots of bigger dimensions (90x30µm) were employed to contain hiPSC-SMCs. Under these conditions, 70-85% of initial dot array occupancy (DAO) was achieved, providing over a thousand cells (events) per SCADA that can be counted for high sensitivity.
Exposure to the cardiotoxic drugs doxorubicin or epirubicin at different concentrations elicited a drastic DAO decrease on 5 different hiPSC lines-derived phenotypes. A robust evaluation of the effect experienced with accumulative doses of both drugs throughout 24h of exposition allowed for the detection of changes in cellular response at several levels: gender, pathological condition, cellular phenotypes and drugs.
This work lays the foundations for uncovering phenotype-specific drug sensitivity, opening the way to high throughput analysis using microfluidics miniaturization, allowing the decrease of sampling volumes and cellular input and specialized equipment.