Materials and Designs for Photoelectroceuticals In Vitro and In Vivo

Recent non-genetic optoelectronic devices, which convert light into electrical or electrochemical currents, have demonstrated efficiency in modulating cells and tissues <i>in vitro</i>, <i>ex vivo</i>, and <i>in vivo</i>.[1] The potential of photoelectrochemical modulation has been explored for its wireless and remote operation, minimally invasive procedures, high spatiotemporal resolution, and immunity to interference from strong electromagnetic fields, leading to the promising field of clinical therapeutic treatments termed “photoelectroceuticals.” In this context, we report innovations in materials and designs for photoelectroceuticals using silicon-based photoelectrochemical devices. By employing rational nanoengineering of monolithic silicon membranes, we developed nanoporous single-crystalline silicon for highly accurate, precise, and localized injection of minority charge carriers (electrons).[2][3] This advancement enables high spatiotemporal and multiscale biological modulation in <i>in vitro</i> cultured rat cardiomyocytes, <i>ex vivo</i> rat heart tissues, and <i>in vivo</i> ischemic rat heart models. Furthermore, we demonstrated reliable multisite cardiac control using millisecond-duration light pulses in a live pig heart experiment under clinical open-thoracic conditions. Additionally, we showcased closed-thoracic pig heart stimulation with a custom endoscopic operation system, highlighting its translational potential. This procedure offers new solutions for temporary heartbeat regulation following open-heart surgeries, which are performed on over two million patients worldwide each year.<br/>Further efforts have concentrated on developing low-power, wearable, and long-term solutions for deep tissue modulation, addressing limitations of current optoelectronic devices.[4] Inspired by neurons, new materials and neuromorphic designs bridge the gap between optically accessible depths and deeper tissues. This approach significantly reduces the required irradiance for optical tissue stimulation by two to three orders of magnitude, ensuring stable performance in fully implanted, long-term applications.<br/><br/>[1] <b><u>P. J. Li</u></b>, S. Kim, B. Z. Tian, Nano-Bioelectronics: Beyond 25 years of Biomedical Innovation. <b><i>Device</i></b>, 2024, in press.<br/>[2] A. Prominski, J. Y. Shi, <b><u>P. J. Li</u></b>, J. P. Yue, Y. L. Lin, J. Park, B. Z. Tian, M. Y. Rotenberg. Porosity-based heterojunctions enable leadless optoelectronic modulation of tissues. <b><i>Nature Materials</i></b>, 2022, DOI: 10.1038/s41563-022-01249-7.