Zhejiang Engineering Research Center of Advanced Mass Spectrometry and Clinical Application, Institute of Mass Spectrometry, School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, China.
Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou 310022, China.
Anal Chem. 2024 Oct 15;96(41):16338-16345. doi: 10.1021/acs.analchem.4c03630. Epub 2024 Oct 3.
In situ visualization of microRNA (miRNA) in cancer cells and diseased tissues is essential for advancing our comprehension of the onset and progression of associated diseases. Two-photon (TP) imaging, as an imaging technology with high spatiotemporal resolution, deep tissue penetration, and accurate target quantification, has distinctive advantages over single-photon imaging and has attracted increasing attention. Extensive research has been conducted on two-photon dye-doped silica nanoparticles, which exhibit a large two-photon absorption (TPA) cross-section, high fluorescence quantum yield, and excellent biocompatibility. However, the low abundance of RNA in tumor cells leads to insufficient signal output. Based on functional nucleic acid, a catalyzed hairpin self-assembly (CHA) signal amplification strategy, which has simplicity, robustness, and nonenzymatic characteristics, can achieve the amplification of DNA or RNA signals. Here, a two-photon silica nanoamplifier (TP-SNA) utilizing TP dye-doped silica nanoparticles (SiNPs) and functional nucleic acid was constructed, employing triggering catalyzed hairpin self-assembly and fluorescence resonance energy transfer (FRET) for highly sensitive detection and precise TP imaging of endogenous miRNAs in tumor cells and tissues at varying depths. The TP-SNA demonstrated the capability to detect miR-203 with a detection limit of 33 pM. The maximum two-photon tissue penetration depth of the two-photon nanoamplifier was 210 μm. The two-photon nanoamplifier developed in this study makes full use of the advantages of accurate TP ratiometric bioimaging and the CHA signal amplification strategy, which shows good application value for future transformation into clinical diagnosis.
在癌症细胞和病变组织中对 microRNA (miRNA) 进行原位可视化对于深入了解相关疾病的发生和发展至关重要。双光子（TP）成像作为一种具有高时空分辨率、深组织穿透能力和准确目标定量的成像技术，相对于单光子成像具有独特的优势，引起了越来越多的关注。双光子染料掺杂二氧化硅纳米粒子的研究已经广泛开展，其具有大的双光子吸收（TPA）截面、高荧光量子产率和良好的生物相容性。然而，肿瘤细胞中 RNA 的丰度较低，导致信号输出不足。基于功能核酸的催化发夹自组装（CHA）信号放大策略具有简单、稳健和非酶特性，可以实现 DNA 或 RNA 信号的放大。在这里，构建了一种利用双光子染料掺杂二氧化硅纳米粒子（SiNPs）和功能核酸的双光子二氧化硅纳米放大器（TP-SNA），采用触发催化发夹自组装和荧光共振能量转移（FRET），实现了肿瘤细胞和组织中内源性 miRNAs 的高灵敏检测和精确的 TP 成像，深度可达到不同的程度。TP-SNA 能够以 33 pM 的检测限检测 miR-203。双光子纳米放大器的最大双光子组织穿透深度为 210 μm。本研究开发的双光子纳米放大器充分利用了准确的双光子比率生物成像和 CHA 信号放大策略的优势，对于未来转化为临床诊断具有很好的应用价值。
