State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
School of Applied Chemical Engineering, University of Science and Technology of China, Road Baohe District, Hefei, Anhui, 230026, P. R. China.
Analyst. 2022 Apr 11;147(8):1581-1588. doi: 10.1039/d2an00212d.
Abnormal expression of matrix metalloproteinases plays an important role in tumor invasion and metastasis. In this report, a peptide modified MnFeO ratiometric fluorescent nanoprobe is developed for noninvasively visualizing the distribution of matrix metalloproteinase-7 (MMP-7) and . A fluorescein isothiocyanate (FITC) modified peptide containing the specific motif VPLSLTMG for MMP-7 cleavage was conjugated with MnFeO nanoparticles (NPs) to establish a Förster resonance energy transfer (FRET) system for sensing the protease. The rhodamine B (RhB) modified targeting peptide immobilized on the nanoparticle surface was not only used as an internal reference for forming a ratiometric fluorescence system together with the FITC dye, but also used for enhancing the tumor targeting ability. The tumor accumulation amount of the as-developed ratiometric fluorescent probe (termed MnFeO-pep-dyes) can be measured by -weighted magnetic resonance (-weighted MR) imaging because MnFeO NPs display an excellent -weighted MR contrast ability. In the presence of MMP-7, FITC detached from the MnFeO surface resulting in the recovery of FITC fluorescence, while no obvious change of the RhB fluorescence was observed. The recovery ratio of FITC to RhB fluorescence intensity is linearly dependent on the MMP-7 concentration within the range of 0.1 to 15 nM in buffer and 5 × 10 to 1 × 10 cells in cell lysates with a limit of detection of 0.1 nM and 436 cells, respectively. MnFeO-pep-dyes was further applied to spatially observe MMP-7 expression in a tumor-bearing mouse by fluorescence imaging with external magnetic field assistance for demonstrating its practicability.
基质金属蛋白酶的异常表达在肿瘤的侵袭和转移中起着重要作用。在本报告中，开发了一种肽修饰的 MnFeO 比率荧光纳米探针，用于非侵入性地可视化基质金属蛋白酶-7（MMP-7）和 的分布。将含有 MMP-7 特异性切割模体 VPLSLTMG 的荧光素异硫氰酸酯（FITC）修饰肽与 MnFeO 纳米颗粒（NPs）偶联，建立了用于感应蛋白酶的Förster 共振能量转移（FRET）系统。固定在纳米颗粒表面的罗丹明 B（RhB）修饰靶向肽不仅用作与 FITC 染料一起形成比率荧光系统的内参，而且还用于增强肿瘤靶向能力。所开发的比率荧光探针（称为 MnFeO-pep-dyes）的肿瘤积累量可以通过 T2-加权磁共振（T2-weighted MR）成像来测量，因为 MnFeO NPs 显示出优异的 T2-加权 MR 对比能力。在存在 MMP-7 的情况下，FITC 从 MnFeO 表面脱离，导致 FITC 荧光恢复，而 RhB 荧光没有明显变化。FITC 与 RhB 荧光强度的恢复比与缓冲液中 0.1 至 15 nM 范围内的 MMP-7 浓度以及细胞裂解物中 5×10 至 1×10 个细胞呈线性相关，检测限分别为 0.1 nM 和 436 个细胞。MnFeO-pep-dyes 进一步通过外部磁场辅助的荧光成像应用于荷瘤小鼠中 MMP-7 表达的空间观察，以证明其实用性。
