Activatable T1 Relaxivity Recovery Nanoconjugates for Kinetic and Sensitive Analysis of Matrix Metalloprotease 2
Activatable T1 Relaxivity Recovery Nanoconjugates for Kinetic and Sensitive Analysis of Matrix Metalloprotease 2
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用于基质金属蛋白酶 2 动力学和灵敏分析的可激活 T-1 弛豫恢复纳米缀合物
DOI：
10.1021/acsami.7b05389
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发表时间：
2017
影响因子：
9.5
通讯作者：
高锦豪
中科院分区：
文献类型：
--
作者：
朱祥龙;林泓域;王俪荣;马棱嶒;陈忠;高锦豪
基质金属蛋白酶2（MMP-2，一种与肿瘤侵袭和转移相关的重要癌症标志物）体外和细胞水平活性的灵敏检测对临床诊断和医疗治疗具有重要意义。纳米颗粒具有独特的物理特性，正在成为构建各种生物分子缀合物的平台，有望产生新型生物传感器。在这项工作中，Fe3O4 NPs 通过连接肽用 Gd 螯合物进行修饰，构建 NP 底物 (Fe3O4-pep-Gd) 缀合物，用于体外细胞水平和体内动态 MMP-2 活性评估。超顺磁性 Fe3O4 通过在外部磁场下扰动质子弛豫过程来猝灭附着的 Gd 螯合物的纵向弛豫效应（T1 弛豫率）。 MMP-2 裂解肽底物并从局部磁场中释放 Gd 螯合物，同时伴随 T1 弛豫度恢复和 T1 对比度增强。 Fe3O4-pep-Gd 缀合物通过将多个 Gd 螯合物与一个连接肽结合而实现信号放大，从而对 MMP-2 的检测表现出高灵敏度（低至 0.5 nM）。酶促过程与整合的 Michaelis-Menten 模型非常一致，揭示了初始阶段意想不到的活性增强。 Fe3O4-pep-Gd 缀合物还可以在细胞水平和体内探测 MMP-2，这表明在体外诊断 (IVD) 和疾病监测方面具有巨大的前景。
Sensitive detection of matrix metalloproteinase 2 (MMP-2, an important cancer marker associated with tumor invasion and metastasis) activity in vitro and at cellular level is of great significance to clinical diagnosis and medical treatment. With unique physical properties, nanoparticles are emerging as a platform for the construction of conjugates of various biological molecules, which can be expected to generate new types of biosensors. In this work, Fe3O4 NPs were modified with Gd chelates via linking peptides to construct NP-substrate (Fe3O4-pep-Gd) conjugates for kinetic MMP-2 activity assessment in vitro at the cellular level and in vivo. Superparamagnetic Fe3O4 quenched the longitudinal relaxation effect (T1 relaxivity) of the attached Gd chelates by perturbing proton relaxation process under an external magnetic field. MMP-2 cleaved the peptide substrates and released Gd chelates from the local magnetic fields accompanied by T1 relaxivity recovery and T1 contrast enhancement. Benefiting from signal amplification through binding multiple Gd chelates to one linking peptide, Fe3O4-pep-Gd conjugates exhibited high sensitivity for the detection of MMP-2 (as low as 0.5 nM). Enzymatic processes were in good agreement with the integrated Michaelis-Menten model, revealing an unexpected activity enhancement in the initial stage. Fe3O4-pep-Gd conjugates could also probe MMP-2 at cellular level and in vivo that indicates a great promise in in vitro diagnosis (IVD) and disease monitoring.