A Precipitation-Enhanced Emission (PEE) Strategy for Increasing the Brightness and Reducing the Liver Retention of NIR-II Fluorophores

A Small-Molecule NIR-II Probe for the Diagnosis of Hemorrhagic Diseases

Numerous hemorrhagic disorders, particularly those presenting deep hemorrhage, pose diagnostic challenges, often leading to delayed treatment and severe outcomes. Near-infrared (NIR)-II fluorescence imaging offers advantages such as deep tissue penetration, real-time visualization, and a high signal-to-background ratio, making it highly suitable for diagnosing hemorrhagic diseases. In this study, an NIR-II fluorescent probe LJ-2P carrying carboxylic and phosphoric acid groups is successfully applied for imaging hemorrhagic diseases. LJ-2P demonstrates a strong affinity for fibrinogen and fibrin clots both computationally and experimentally, thus exhibiting increased brightness upon coagulation. As compared to Indocyanine Green, LJ-2P provides a longer imaging window, higher imaging specificity, and signal-to-background ratio, as well as superior photobleaching resistance in three disease models: gastric, pulmonary, and cerebral hemorrhages. These results reveal that LJ-2P demonstrates enhanced imaging capabilities, enabling precise identification of hemorrhagic sites.

Polymeric engineering of AIEgens for NIR-II fluorescence imaging and detection of abdominal metastases of ovarian cancer in vivo

A polymeric engineering design principle is proposed for the construction of small-sized (∼20 nm) NIR-II AIEgen-doped nanodots (AIEdots) with high brightness and prolonged circulation time in blood vessels. With the utilization of the as-designed NIR-II AIEdots, the successful achievement of high-resolution NIR-II fluorescence imaging of tumor vessels and precise detection of abdominal metastases of ovarian cancer has been attained.

Nanoparticle-Based Photothermal Therapy for Breast Cancer Noninvasive Treatment

Rapid advancements in materials science and nanotechnology, intertwined with oncology, have positioned photothermal therapy (PTT) as a promising noninvasive treatment strategy for cancer. The breast's superficial anatomical location and aesthetic significance render breast cancer a particularly pertinent candidate for the clinical application of PTT following melanoma. This review comprehensively explores the research conducted on the various types of nanoparticles employed in PTT for breast cancer and elaborates on their specific roles and mechanisms of action. The integration of PTT with existing clinical therapies for breast cancer is scrutinized, underscoring its potential for synergistic outcomes. Additionally, the mechanisms underlying PTT and consequential modifications to the tumor microenvironment after treatment are elaborated from a medical perspective. Future research directions are suggested, with an emphasis on the development of integrative platforms that combine multiple therapeutic approaches and the optimization of nanoparticle synthesis for enhanced treatment efficacy. The goal is to push the boundaries of PTT toward a comprehensive, clinically applicable treatment for breast cancer.

In Vivo Fate of CXCR2-Overexpressing Mesenchymal Stromal/Stem Cells in Pulmonary Diseases Monitored by Near-Infrared Region 2 Imaging

Lung-associated diseases pose a huge threat to human society. Mesenchymal stromal/stem cells (MSCs) hold great promise in the treatment of pulmonary diseases through cell transdifferentiation, paracrine factors, immune regulation, EV secretion, and drug loading. However, intravenous injection of MSCs often resulted in limited lesion tropism and apparent off-target accumulation. The IL-8-CXCR1/2 chemokine axis has been shown to be involved in progression of diseases including lung cancer and acute lung injury (ALI). Herein, we took advantage of this chemokine axis to enhance the homing of MSCs to cancerous and inflammation lesions. The in vivo distribution of MSCs was further monitored real-time by near-infrared region 2 (NIR-II) imaging owing to its outstanding performance in deep tissue imaging. Specifically, a new high-brightness D-A-D NIR-II dye, LJ-858, was synthesized and coprecipitated with a poly(d,l-lactic acid) polymer to form LJ-858 nanoparticles (NPs) with a relative quantum yield of 14.978%. LJ-858 NPs can efficiently label MSCs, and the NIR-II signal can be stable for 14 days without compromising the cell viability. Subcutaneous tracking of labeled MSCs showed no significant decline of NIR-II intensity within 24 h. The enhanced tropism of CXCR2-overexpressing MSCs to A549 tumor cells and the inflamed lung tissue was demonstrated through transwell models. The in vivo and ex vivo NIR-II imaging results further validated the significantly enhanced lesion retention of MSC^CXCR2 in the lung cancer and ALI models. Taken together, this work reported a robust strategy to enhance the pulmonary disease tropism by the IL-8-CXCR1/2 chemokine axis. In addition, in vivo distribution of MSCs was successfully visualized by NIR-II imaging, which provides more insights into optimizing protocols for MSC-based therapies in the future.