The Down-Shifting Luminescence of Rare-Earth Nanoparticles for Multimodal Imaging and Photothermal Therapy of Breast Cancer.

Simple Summary: The global cancer report for 2020 highlights a noteworthy surge in new cases of breast cancer, exceeding lung cancer incidence for the first time and emerging as the foremost global cancer manifestation. Breast cancer has become a prominent contributor to female cancer-related mortality. Surgical removal continues to be a primary therapeutic recourse for breast cancer patients, aiming to extend survival by addressing residual tumor foci during surgery. However, the challenge lies in achieving complete excision due to the ambiguous boundaries of tumors. NIR-II imaging, known for its heightened sensitivity, superior spatiotemporal resolution, and enhanced optical penetration depth compared to conventional optical imaging, stands out as an optimal choice for preoperative and real-time intraoperative imaging, particularly in live fluorescence imaging. Within this study, rare-earth nanoparticles α-Er NPs exhibit remarkable imaging quality in breast cancer, incorporating X-ray computed tomography and ultrasound, collectively enhancing precision in cancer diagnosis and treatment. Additionally, the study explores the photothermal therapeutic effects of α-Er NPs. Through the combination of NIR-II imaging technology with rare-earth probes, the research pioneers a secure and effective novel strategy for the precise diagnosis and treatment integration of breast cancer, establishing a robust foundation for future advancements in medical applications. Nanotheranostic agents capable of simultaneously enabling real-time tracking and precise treatment at tumor sites play an increasingly pivotal role in the field of medicine. In this article, we report a novel near-infrared-II window (NIR-II) emitting downconversion rare-earth nanoparticles (RENPs) to improve image-guided therapy for breast cancer. The developed α-NaErF4@NaYF4 nanoparticles (α-Er NPs) have a diameter of approximately 24.1 nm and exhibit superior biocompatibility and negligible toxicity. RENPs exhibit superior imaging quality and photothermal conversion efficiency in the NIR-II range compared to clinically approved indocyanine green (ICG). Under 808 nm laser irradiation, the α-Er NPs achieve significant tumor imaging performance and photothermal effects in vivo in a mouse model of breast cancer. Simultaneously, it combines X-ray computed tomography (CT) and ultrasound (US) tri-modal imaging to guide therapy for cancer. The integration of NIR-II imaging technology and RENPs establishes a promising foundation for future medical applications. [ABSTRACT FROM AUTHOR]