MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Qingyuan Innovation Laboratory, 1# Xueyuan Road, Quanzhou, Fujian 362801, China.
Anal Chem. 2022 Feb 8;94(5):2641-2647. doi: 10.1021/acs.analchem.1c05154. Epub 2022 Jan 27.
Ultrasmall gold nanoclusters (AuNCs) are emerging as promising luminescent nanoprobes for bioimaging due to their fantastic photoluminescence (PL) and renal-clearable ability. However, it remains a great challenge to design them for in vivo sensitive molecular imaging in desired tissues. Herein, we have developed a strategy to tailor the PL and biofate of near-infrared II (NIR-II)-emitting AuNCs via ligand anchoring for improved bioimaging. By optimizing the ligand types in AuNCs and using Er-doped lanthanide (Ln) nanoparticles as models, core-satellite Ln@AuNCs assemblies were rationally constructed, which enabled 2.5-fold PL enhancement of AuNCs at 1100 nm and prolonged blood circulation compared to AuNCs. Significantly, Ln@AuNCs with dual intense NIR-II PL (from AuNCs and Er) can effectively accumulate in the liver for ratiometric NIR-II imaging of HS, facilitated by HS-mediated selective PL quenching of AuNCs. We have then demonstrated the real-time imaging evaluation of liver delivery efficacy and dynamics of two HS prodrugs. This shows a paradigm to visualize liver HS delivery and its prodrug screening in vivo. Note that Ln@AuNCs are body-clearable via the hepatobiliary excretion pathway, thus reducing potential long-term toxicity. Such findings may propel the engineering of AuNC nanoprobes for advancing in vivo bioimaging analysis.
超小的金纳米团簇（AuNCs）由于其出色的光致发光（PL）和肾脏清除能力，正在成为生物成像中很有前途的发光纳米探针。然而，设计用于在所需组织中进行体内敏感分子成像的 AuNCs 仍然是一个巨大的挑战。在此，我们开发了一种通过配体锚定来定制近红外二区（NIR-II）发射 AuNCs 的 PL 和生物命运的策略，以改善生物成像。通过优化 AuNCs 中的配体类型，并以掺铒的镧系（Ln）纳米颗粒作为模型，合理构建了核-卫星 Ln@AuNCs 组装体，与 AuNCs 相比，AuNCs 在 1100nm 处的 PL 增强了 2.5 倍，血液循环时间延长。值得注意的是，具有双重强烈近红外二区 PL（来自 AuNCs 和 Er）的 Ln@AuNCs 可以有效地在肝脏中积累，用于 HS 的比率型近红外二区成像，这得益于 HS 介导的 AuNCs 的选择性 PL 猝灭。我们随后证明了两种 HS 前药肝递送效果和动力学的实时成像评估。这表明了一种可视化肝 HS 递送及其体内前药筛选的范例。请注意，Ln@AuNCs 可通过肝胆排泄途径清除，从而降低潜在的长期毒性。这些发现可能推动 AuNC 纳米探针的工程设计，以推进体内生物成像分析。
