Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering Northwestern Polytechnical University, Xi'an, 710072, China; College of Pharmaceutical Sciences, Anhui Xinhua University, Hefei, 230088, China.
Institute of Flexible Electronics (IFE, Future Technologies), Xiamen University, Xiamen, 361005, China; Future Display Institute in Xiamen, Xiamen, 361005, China.
Biosens Bioelectron. 2025 Jan 1;267:116823. doi: 10.1016/j.bios.2024.116823. Epub 2024 Sep 30.
Fluorescence imaging technology has emerged as a powerful tool for studying intricate mitochondrial morphology within living cells. However, the need for fluorophores with stable fluorescence intensity and low phototoxicity poses significant challenges, particularly for long-term live-cell mitochondrial monitoring. To address this, we introduce the confinement fluorescence effect (CFE) into the design of fluorophores. This strategy involves confining small-molecule fluorophores within a silicon suboxide network structure of nanoparticles (CEF-NPs), which restricts molecular rotation, resulting in the suppression of non-radiative transition and the isolation of encapsulated fluorophores from surrounding quenching factors. CFE-NPs (SY2@SiOx) exhibit exceptional properties, such as high fluorescence intensity (80-fold) and reduced phototoxicity (0.15-fold). Furthermore, the TPP + -functionalized CFE-NPs (SY2@SiOxTPP) demonstrated efficacy in mitochondrial imaging and mitochondrial dynamics monitoring. Biochemistry assays indicated that SY2@SiOxTPP exhibits significantly lower phototoxicity to mitochondrial functions compared to both small-molecule fluorophore and commercial Mito Tracker. This approach allows for the long-term dynamic monitoring of mitochondrial morphological changes through fluorescence imaging, without impairing mitochondrial functionality.
荧光成像技术已成为研究活细胞内复杂线粒体形态的有力工具。然而，对于具有稳定荧光强度和低光毒性的荧光染料的需求仍然存在很大的挑战，特别是在长期的活细胞线粒体监测中。为了解决这个问题，我们将限制荧光体的约束荧光效应（CFE）引入到荧光染料的设计中。这种策略涉及将小分子荧光染料限制在纳米颗粒的氧化硅网络结构内（CEF-NPs），这限制了分子的旋转，从而抑制了非辐射跃迁，并将被封装的荧光染料与周围的猝灭因子隔离开来。CEF-NPs（SY2@SiOx）表现出了出色的性质，例如高荧光强度（80 倍）和降低的光毒性（0.15 倍）。此外，TPP + 功能化的 CFE-NPs（SY2@SiOxTPP）在线粒体成像和线粒体动力学监测中表现出了很好的效果。生物化学测定表明，与小分子荧光染料和商业的 Mito Tracker 相比，SY2@SiOxTPP 对线粒体功能的光毒性要低得多。这种方法可以通过荧光成像进行长期的线粒体形态变化的动态监测，而不会损害线粒体的功能。
