Department of Chemistry, Shanghai Stomatological Hospital, State Key Laboratory of Molecular Engineering of Polymers, Institute of Biomedical Sciences, Fudan University, Shanghai, 200438, China.
Shanghai Institute for Pediatric Research, Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
Biosens Bioelectron. 2022 Jul 1;207:114194. doi: 10.1016/j.bios.2022.114194. Epub 2022 Mar 21.
Accurate discrimination between different cells at the molecular level is of fundamental importance for disease diagnosis. Endogenous proteases are such molecular candidates for cancer cell subtype study. But in situ probing their activity in live cells remains challenging for surface-enhanced Raman scattering (SERS). Here, we present a sensitive ratio-type SERS nanoprobe for imaging of matrix metalloproteinase-2 (MMP-2) in different cancer cells subtypes. The nanoprobe contained three components: a plasmon-active gold nanoparticle as the SERS enhancing matrix, Raman dye rhodamine B (Rh B)-labelled substrate peptides as the specific MMP-2 recognizer, and 2-naphthalenethiol (2-NT) as the internal standard. MMP-2-responsive cleavage of peptides from the nanoprobe surface results in decrease or even disappearance of SERS emission of Rh B, which was ratioed over the emission of 2-NT for the quantification of MMP-2 activity. Both in-tube assay and in-cell imaging results show that the MMP-responsive nanoprobe can work and serve to differentiate the normal breast cells from the tumorous ones, to differentiate two breast cancer cell subtypes with a different degree of malignancy. We believe that this SERS nanoprobe could find a wide application in the fields of tumor biology and accurate disease diagnosis.
在分子水平上准确区分不同的细胞对疾病诊断至关重要。内源性蛋白酶是用于癌症细胞亚型研究的此类分子候选物。但在活细胞中原位探测其活性对表面增强拉曼散射（SERS）仍然具有挑战性。在这里，我们提出了一种灵敏的比率型 SERS 纳米探针，用于成像不同癌症细胞亚型中的基质金属蛋白酶-2（MMP-2）。该纳米探针包含三个组成部分：等离子体活性金纳米颗粒作为 SERS 增强基质，罗丹明 B（Rh B）标记的基质肽作为特定 MMP-2 识别物，以及 2-萘硫醇（2-NT）作为内标。肽从纳米探针表面的 MMP-2 响应性切割导致 Rh B 的 SERS 发射减少甚至消失，通过 Rh B 的发射与 2-NT 的发射的比值来定量 MMP-2 活性。管内测定和细胞内成像结果均表明，该 MMP 响应性纳米探针可用于区分正常乳腺细胞与肿瘤细胞，区分两种恶性程度不同的乳腺癌细胞亚型。我们相信，这种 SERS 纳米探针在肿瘤生物学和准确疾病诊断领域有广泛的应用前景。
