Noninvasive Promotion of Neuronal Differentiation in Human Neural Progenitor Cells Using Terahertz Wave Illumination

Abstract

Recent advances in neuromodulation have demonstrated the importance of precise and minimally invasive strategies for modulating neuronal function. Terahertz (THz) wave has emerged as a promising method due to its low photon energy and ability to interact with biomolecular vibrational modes without inducing ionization. These frequency-specific interactions can affect water dynamics around biomolecules, modify molecular interactions, and alter cellular signaling processes that influence neuronal responses. In this study, the effects of THz irradiation on the differentiation of human neural progenitor cells in terms of safety and enhancement are investigated. Cellular safety is assessed using viability assays, live/dead imaging, and expression analysis of stress-related genes. All of these results indicate absence of cytotoxic effects after THz exposure. Concurrently, the THz irradiation significantly promotes neuronal differentiation, evidenced by lower levels of stemness markers (SOX2, Nestin) and higher levels of neuronal markers (beta 3-tubulin, GAP43) in both quantitative Polymerase Chain Reaction (qPCR) and immunocytochemistry (ICC). Morphological analyses further reveal enhanced neurite-associated structures in THz-exposed cells. These findings collectively indicate that THz irradiation can alter neuronal differentiation while maintaining cellular integrity. Such properties suggest THz exposure as a promising noninvasive tool for modulating neural development and function.