Photocleavable Systems for Cell Biology: Conceptual Design across Molecular Modalities

The spatiotemporal control of biomolecular functions via light-triggered bond cleavage has emerged as a powerful approach in chemical biology and cell biology. In this concept review, three major modalities of photo-cleavable systems-proteins, small molecules, and metal complexes-are classified and discussed, highlighting their design principles, biological applicability, and remaining challenges. Emphasis is placed on recent efforts to address key design challenges-such as balancing functional performance, biological compatibility, and optical responsiveness-across different molecular modalities, offering perspectives for the next generation of photo-responsive tools for biological research.