Micropatterned Hydrogels with Highly Ordered Cellulose Nanocrystals for Visually Monitoring Cardiomyocytes

Cardiac microphysiological systems are accurate in vitro platforms that reveal the biological mechanisms underlying cardiopathy, accelerating pharmaceutical research in this field. Current cardiac microphysiological devices and organs‐on‐chips consist of several layers prepared with complex, multi‐step processes. Incorporating inorganic photonic crystals may cause long‐term biocompatibility issues. Herein, micropatterned hydrogels with anisotropic structural colors are prepared by locking shear‐oriented tunicate cellulose nanocrystals (TCNCs) in hydrogel networks through in situ polymerization, allowing the visualization and monitoring of cardiomyocytes. The anisotropic hydrogels are composed of highly ordered TCNCs with bright interference color and micro‐grooved methacrylated gelatin with excellent biocompatibility. The microgroove patterns induce cardiomyocyte alignment and the autonomous beating of cardiomyocytes causes the hydrogels to deform, dynamically shifting the interference color. These micropatterned hydrogels could noninvasively monitor real‐time changes of cardiomyocytes under pharmaceutical treatment and electrical stimulation through wavelength shifts in the transmittance spectra. This system provides a new way to detect the beat rate of cardiac tissue and it may contribute to high throughput develop. A facile and fast method for constructing anisotropic structural color from biocompatible materials for the multi‐chamber detection of cardiomyocytes is proposed here. These micropatterned hydrogels can noninvasively monitor real‐time changes of cardiomyocytes under drug treatment and electrical stimulation through wavelength shifts in the spectra. This system shows a great prospect in monitoring patient‐specific human‐induced pluripotent stem cell‐derived cardiomyocytes for research and drug development.