Cephalopod-Inspired Optical Engineering of Mammalian Cells

During the last several decades, cephalopods (e.g., squids, octopuses, and cuttlefish) have emerged as a powerful source of inspiration for the engineering of dynamic optical systems, due to their complex nervous systems, diverse behavioral patterns, and tunable structural coloration. We drew inspiration from the tunable optical functionality of cephalopod skin cells to engineer human cells for production of reflectin-based high refractive index subcellular architectures and, as a result, to possess tunable transparency-changing and light scattering capabilities (1). Additionally, we improved our control over the production of reflectin in human cells by genetically engineering cell lines to stably express reflectin, which enabled more extensive studies of reflectin-based subcellular architectures under physiological conditions (2). Moreover, we evaluated the optical properties of single cells with three-dimensional label-free holotomographic microscopy and quantitatively characterized their subcellular reflectin-based architectures without and with external chemical stimuli (1,2). Finally, we demonstrated the potential applications of high refractive index reflectin-based subcellular architectures as high contrast genetically encoded biomolecular reporters for various types of microscopy techniques (2,3). Our combined findings validate prior postulates about the mechanisms of cephalopod tunable skin coloration and may lead to the development of unique protein-based tools for various applications in biophotonics and bioengineering.<br/> <br/>1) Chatterjee A., et al., <i>Nat Commun.,</i> <b>11</b>, 2708 (2020).<br/>2) Bogdanov G., et al., <i>iScience</i>, 106854 (2023).<br/>3) Chatterjee A., et al., <i>ACS Biomater. Sci. Eng.,</i> <b>9</b>, 978–990 (2023).