A Functional Iron Oxide Nanoparticles Modified with PLA-PEG-DG as Tumor-Targeted MRI Contrast Agent.

PURPOSE: Tumor targeting could greatly promote the performance of magnetic nanomaterials as MRI (Magnetic Resonance Imaging) agent for tumor diagnosis. Herein, we reported a novel magnetic nanoparticle modified with PLA (poly lactic acid)-PEG (polyethylene glycol)-DG (D-glucosamine) as Tumor-targeted MRI Contrast Agent. METHODS: In this work, we took use of the D-glucose passive targeting on tumor cells, combining it on PLA-PEG through amide reaction, and then wrapped the PLA-PEG-DG up to the Fe3O4@OA NPs. The stability and anti phagocytosis of Fe3O4@OA@PLA-PEG-DG was tested in vitro; the MRI efficiency and toxicity was also detected in vivo. RESULTS: These functional magnetic nanoparticles demonstrated good biocompatibility and stability both in vitro and in vivo. Cell experiments showed that Fe3O4@OA@PLA-PEG-DG nanoparticles exist good anti phagocytosis and high targetability. In vivo MRI images showed that the contrast effect of Fe3O4@OA@PLA-PEG-DG nanoparticles prevailed over the commercial non tumor-targeting magnetic nanomaterials MRI agent at a relatively low dose. CONCLUSIONS: The DG can validly enhance the tumor-targetting effect of Fe3O4@OA@PLA-PEG nanoparticle. Maybe MRI agents with DG can hold promise as tumor-targetting development in the future.

Thiadiazoloquinoxaline derivative-based NIR-II organic molecules for NIR-II fluorescence imaging and photothermal therapy.

NIR-II FI has emerged as a promising imaging tool for in vivo precise diagnosis and visualization towards various diseases, ascribed to its merits of attenuated light scattering and tissue absorption and ignorable auto-fluorescence. Owing to its superiority in high specificity, low toxicity, and ignorable invasiveness, photothermal therapy (PTT) has developed as one of the most potential treatment methods for cancer treatment. Although organic optical agents with a donor-acceptor-donor (D-A-D) skeleton have been extensively applied to NIR-II FI and PTT, most were based on the three weak electron acceptors benzobisthiadiazole (BBTD), diketopyrrolopyrrole (DPP), and thiadiazoloquinoxaline (TTQ). Although the acceptor TTQ has developed as a promising acceptor to synthesize molecules for high-resolution NIR-II FI and PTT, reviews focused on TTQ based NIR-II organic molecules for NIR-II FI and PTT were still rarely reported. Hence, this review systemically summarized the current advanced process of TTQ based D-A-D type organic molecules for NIR-II FI and PTT. Firstly, some examples for NIR-II FI of tissue and immune and thrombosis NIR-II FI were presented in detail. Some examples of NIR-II FI-navigated PTT or combination therapy were discussed. Finally, some pending challenges in applying them to NIR-II FI and PTT are discussed.

D-A Type NIR-II Organic Molecules: Strategies for the Enhancement Fluorescence Brightness and Applications in NIR-II Fluorescence Imaging-Navigated Photothermal Therapy.

NIR-II fluorescence imaging (NIR-II FI) and photothermal therapy (PTT) have received broad attentions in precise tumor diagnosis and effective treatment attributed to high-resolution and deep tissue imaging, negligible invasivity, and high-efficiency treatment. Although many fluorescent molecules have been designed and conducted for NIR-II FI and PTT, it is still an enormous challenge for researchers to pioneer some rational design guidelines to improve fluorescence brightness. Organic D-A-type molecules, including small molecules and conjugated polymers, can be designed and developed to improve fluorescence brightness due to their tunable and easy functionalized chemical structures, allowing molecules tailored photophysical properties. In this review, some approaches to the development and design strategies of D-A type small molecules and conjugated polymers for the enhancement of fluorescence brightness are systemically introduced. Meanwhile, some applications of PTT and PTT-based combination therapy (such as PDT, chemotherapy, or gas therapy) assisted by NIR-II FI-based single or multiimaging technologies are classified and represented in detail as well. Finally, the current issues and challenges of NIR-II organic molecules in NIR-II FI-navigated PTT are summarized and discussed, which gives some guidelines for the future development direction of NIR-II organic molecules for NIR-II FI-navigated PTT.