Red blood cell–hitchhiking fluorescent probe to promote intraoperative diagnosis of human ovarian tumor

Ovarian cancer is the deadliest gynecological malignancy. The fluorescence-guided surgery technique provides a real-time visualization of the desired regions to guide the tumor resection. However, the fluorescent probes used in clinics suffer from the limited selectivity of ovarian tumors and short blood circulation half-lives. Here, we design an activatable trident-like fluorescent peptide probe (RMN) to bind with the ovarian tumor-overexpressed N-cadherin and respond to the matrix metalloproteinases (MMPs). Upon intravenous administration, the RMN initially hitchhikes on the red blood cell (RBC) surface with prolonged circulation half-lives. When arriving at the tumor regions, the peptide sequence is cleaved by the tumor-secreted MMPs to recover the fluorescent signals. The released "spears" containing N-cadherin-targeting moiety and fluorophore can specifically recognize the ovarian tumor cells, thereby facilitating the visualization of primary or metastatic tumor regions. Overall, this study highlights the potential of RBC-hitchhiking fluorescent probes in advancing the intraoperative diagnosis of human ovarian tumor tissues during the fluorescence-guided surgery process in clinics.