Ueya Yuichi, Umezawa Masakazu, Takamoto Eiji, Yoshida Moe, Kobayashi Hisanori, Kamimura Masao, Soga Kohei
Tsukuba Research Laboratories, JSR Corporation 25 Miyukigaoka Tsukuba Ibaraki 305-0841 Japan.
Department of Materials Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science 6-3-1 Niijuku Katsushika Tokyo 125-8585 Japan
RSC Adv. 2021 May 25;11(31):18930-18937. doi: 10.1039/d1ra01040a. eCollection 2021 May 24.
Polystyrene-based nanoparticles (PSt NPs) prepared by emulsion polymerization are promising organic matrices for encapsulating over-thousand-nanometer near-infrared (OTN-NIR) fluorescent dyes, such as thiopyrilium IR-1061, for OTN-NIR dynamic live imaging. Herein, we propose an effective approach to obtain highly emissive OTN-NIR fluorescent PSt NPs (OTN-PSt NPs) in which the polarity of the PSt NPs was adjusted by changing the monomer ratio (styrene to acrylic acid) in the PSt NPs and the dimethyl sulfoxide concentration in the IR-1061 loading process. Moreover, OTN-PSt NPs covalently modified with poly(ethylene glycol) (PEG) (OTN-PSt-PEG NPs) showed high dispersion stability under physiological conditions and minimal cytotoxicity. Notably, the optimized OTN-PSt-PEG NPs were effective in the dynamic live imaging of mice. This methodology is expected to facilitate the design of certain polar thiopyrilium dye-loaded OTN-NIR fluorescent imaging probes with high emissivity.
通过乳液聚合制备的聚苯乙烯基纳米颗粒（PSt NPs）是用于封装超千纳米近红外（OTN-NIR）荧光染料（如硫代吡喃鎓IR-1061）以进行OTN-NIR动态活体成像的有前景的有机基质。在此，我们提出了一种有效的方法来获得高发射性的OTN-NIR荧光PSt NPs（OTN-PSt NPs），其中通过改变PSt NPs中的单体比例（苯乙烯与丙烯酸）以及IR-1061负载过程中的二甲基亚砜浓度来调节PSt NPs的极性。此外，用聚乙二醇（PEG）共价修饰的OTN-PSt NPs（OTN-PSt-PEG NPs）在生理条件下表现出高分散稳定性和最小细胞毒性。值得注意的是，优化后的OTN-PSt-PEG NPs在小鼠动态活体成像中是有效的。该方法有望促进某些具有高发射率的负载极性硫代吡喃鎓染料的OTN-NIR荧光成像探针的设计。
