An Integrative\nProbe for Tumor Therapy and Dual-Modal\nSelf-Evaluation Imaging of Therapeutic Efficacy

Currently, independent tumor therapy and evaluation methods\ncan\nnot achieve real-time evaluation. Therefore, development of a self-evaluation\nstrategy is urgently needed. To the best of our knowledge, there is\nno multimodal self-evaluation strategy. Herein, we design an integrative\nprobe (<b>CPT-SS-DEVD-HCy</b>) for tumor therapy and dual-modal\nself-evaluation imaging. In tumor cells, the high concentration of\nglutathione (GSH) specifically induces <b>CPT-SS-DEVD-HCy</b> to release CPT, which generates apoptosis with the activation of\ncaspase-3 (Casp-3). Subsequently, activated Casp-3 further specifically\ncleaves peptide substrate to release hemicyanine (HCy) dye, thus generating\na fluorescent/photoacoustic (FL/PA) dual-modal signal for self-evaluation\nimaging. Cell experiments show that <b>CPT-SS-DEVD-HCy</b> can\neffectively kill tumor cells through GSH-instructed CPT release and\nfurther image Casp-3 activity during apoptosis with a 5.1-/6.4-fold\nincreased FL/PA signal. Moreover, <b>CPT-SS-DEVD-HCy</b> displays\na high tumor inhibition effect and is competently able to self-evaluate\nthe tumor therapeutic effect <i>in vivo</i>. We envision\nthat this work will be helpful for developing more self-evaluation\nimaging probes in the future.