Aptamer-based NIR II imaging for breast cancer surgical resection.

The accuracy of intraoperative tumor margin assessment is the main challenge in breast conserving surgery (BCS). NIR-II fluorescence-guided surgery enables surgeons to visualize the tumor margins dynamically in real time and facilitate the precision of tumor resection. We develop an aptamer-conjugated NIR-II probe for intraoperative fluorescence imaging. Peglated indocyanine green (PEG-ICG) was conjugated with an aptamer SYL3C binding to EpCAM to synthesize the probe SYL3C-ICG. Human breast cancer cell lines with different expression levels of EpCAM were employed to assess its tumor-targeting capability. Tumor xenograft models were established to investigate the in vivo selectivity of SYL3C-ICG, and a segmental excision procedure was employed to evaluate the efficacy of the probe in navigating precise surgical resection under NIR-II imaging. In vitro and in vivo fluorescence imaging revealed that NIR-II provides superior imaging resolution and penetration depth compared to NIR-I, and SYL3C-ICG could selectively accumulate at the tumor site, which helps surgeons detect tiny residual malignant lesions invisible to the naked eye and reduce the postoperative recurrence rate.