Compact Molecular Conformation of Prodrugs Enhances Photocleaving Performance for Tumor Vascular Growth Inhibition

Highly spatiotemporal-resolved photomodulation demonstrates promise for investigating key biological events in vivo and in vitro, such as cell signaling pathways, neuromodulation, and tumor treatment without side effects. However, enhancing the performance of photomodulation tools remains challenging due to the limitations of the physicochemical properties of the photoactive molecules. Here, a compact, stable intramolecular π-π stacking conformation forming between the target molecule (naproxen) and the perylene-based photoremovable protecting group is discovered to confine the motion of the photolabile bond and then enhance the photocleavage quantum yield. In conjunction with a red-absorbing photosensitizer, the photocleavage wavelength is extended to the red region via triplet-triplet annihilation. In particular, the triplet lifetime of the prodrug can be extended via the linked steric hindrance to improve the conversion yield via TTA. Using the new photomodulation tool, it is precisely photoreleased cyclooxygenase-2 inhibitors for tumor vascular growth suppression in vivo. In combination with cisplatin, over 90% efficient inhibition of malignant breast tumors is observed via the synergistic tumor treatment strategy. These findings provide a new concept for the rational design of efficient photocleavage and have implications for photomodulating cell signaling pathways in tumor therapy, as well as laying a solid foundation for the development of phototherapeutic approaches.