Visualizing Tumors in Real Time: A Highly Sensitive PSMA Probe for NIR-II Imaging and Intraoperative Tumor Resection

Owing
to the complex anatomical structure, precise resection of
a tumor while maintaining adjacent tissue is a challenge in radical
prostatectomy for prostate cancer (PCa). Optical imaging in near-infrared
window II (NIR-II) is a promising technology for intraoperative guidance,
whereas there is no available probe for PCa yet. In this article,
a novel probe (PSMA-1092) bearing two prostate-specific
membrane antigen (PSMA) binding motifs was developed, displaying excellent
optical properties (λmax = 1092 nm) and ultrahigh
affinity (Ki = 80 pM) toward PSMA. The
tumor was visualized with high resolution (tissue-to-normal tissue
ratio = 7.62 ± 1.05) and clear margin by NIR-II imaging using PSMA-1092 in a mouse model. During the tumor resection, residual
tumors missed by visible inspection were detected by the real-time
imaging. Overall, PSMA-1092 displayed excellent performance
in delineating the tumor margin and detecting residual tumors, demonstrating
promising potential for precise PCa tumor resection in clinical practice.