Real-time detection and resection of sentinel lymph node metastasis in breast cancer through a rare earth nanoprobe based NIR-IIb fluorescence imaging.

Sentinel lymph node (SLN) biopsy is a commonly employed procedure for the routine assessment of axillary involvement in patients with breast cancer. Nevertheless, conventional SLN mapping cannot reliably distinguish the presence and absence of metastatic disease. Additionally, the complex anatomical structures and lymphatic drainage patterns surrounding tumor sites pose challenges to the sensitivity of the near-infrared fluorescence imaging with subcutaneously injected probes. To identifying the SLN metastases, we developed a novel nanoprobe for in vivo fluorescence imaging within the second near-infrared (NIR-II) range. This nanoprobe utilizes rare-earth nanoparticles (RENPs) to emit bright fluorescence at 1525 nm and is conjugated with tumor-targeted hyaluronic acid (HA) to facilitate the detection of metastatic SLN. Upon intravenous administration, RENPs@HA effectively migrated to SLNs and selectively entered metastatic breast tumor cells through CD44-mediated endocytosis. The RENPs@HA nanoprobes exhibited rapid accumulation in metastatic inguinal lymph nodes in mouse model, displaying a 5.8-fold-stronger fluorescence intensity to that observed in normal SLNs. Consequently, these nanoprobes effectively differentiate metastatic SLNs from normal SLNs. Importantly, the probes accurately detected micrometastases. These findings underscore the potential of RENPs@HA for real-time visualization and screening of SLNs metastasis.

Estimating dynamic vascular perfusion based on Er-based lanthanide nanoprobes with enhanced down-conversion emission beyond 1500 nm.

Peripheral artery disease (PAD) is a common, yet serious, circulatory condition that can increase the risk of amputation, heart attack or stroke. Accurate identification of PAD and dynamic monitoring of the treatment efficacy of PAD in real time are crucial for optimizing therapeutic outcomes. However, current imaging techniques do not enable these requirements. Methods: A lanthanide-based nanoprobe with emission in the second near-infrared window b (NIR-IIb, 1500-1700 nm), Er-DCNPs, was utilized for continuous imaging of dynamic vascular structures and hemodynamic alterations in real time using PAD-related mouse models. The NIR-IIb imaging capability, stability, and biocompatibility of Er-DCNPs were evaluated in vitro and in vivo. Results: Owing to their high temporal-spatial resolution in the NIR-IIb imaging window, Er-DCNPs not only exhibited superior capability in visualizing anatomical and pathophysiological features of the vasculature of mice but also provided dynamic information on blood perfusion for quantitative assessment of blood recovery, thereby achieving the synergistic integration of diagnostic and therapeutic imaging functions, which is very meaningful for the successful management of PAD. Conclusion: Our findings indicate that Er-DCNPs can serve as a promising system to facilitate the diagnosis and treatment of PAD as well as other vasculature-related diseases.