Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, China.
The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2022 Jul;14(4):e1786. doi: 10.1002/wnan.1786. Epub 2022 Feb 28.
Enzyme-mediated intratumoral self-assembled (EMISA) nanotheranostics represent a new class of smart agents for combined imaging and therapy of cancer. Cancer cells overexpress various enzymes that are essential for high metabolism, fast proliferation, and tissue invasion and metastasis. By conjugating small molecules that contain an enzyme-specific cleavage site to appropriate chemical linkers, it is possible to induce self-assembly of nanostructures in tumor cells having the target enzyme. This approach of injecting small theranostic molecules that eventually become larger nanotheranostics in situ avoids some of the major limitations that are encountered when injecting larger, pre-assembled nanotheranostics. The advantage of EMISA nanotheranostics include the avoidance of nonspecific uptake and rapid clearance by phagocytic cells, increased cellular accumulation, reduced drug efflux and prolonged cellular exposure time, all of which lead to an amplified imaging signal and therapeutic efficacy. We review here the different approaches that can be used for preparing EMISA-based organic, inorganic, or organic/inorganic hybrid nanotheranostics based on noncovalent interactions and/or covalent bonding. Imaging examples are shown for fluorescence imaging, nuclear imaging, photoacoustic imaging, Raman imaging, computed tomography imaging, bioluminescent imaging, and magnetic resonance imaging. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Biology-Inspired Nanomaterials > Peptide-Based Structures.
酶介导的肿瘤内自组装（EMISA）纳米诊疗剂代表了一类新的智能药物，可用于癌症的联合成像和治疗。癌细胞过度表达各种酶，这些酶对于高代谢、快速增殖以及组织侵袭和转移是必不可少的。通过将含有酶特异性切割位点的小分子与适当的化学连接子偶联，可以诱导具有靶酶的肿瘤细胞中的纳米结构自组装。这种注射小分子治疗剂的方法最终在原位形成更大的纳米诊疗剂，避免了注射较大的预组装纳米诊疗剂时遇到的一些主要限制。EMISA 纳米诊疗剂的优点包括避免被吞噬细胞非特异性摄取和快速清除、增加细胞积累、减少药物外排和延长细胞暴露时间，所有这些都导致成像信号和治疗效果增强。我们在这里综述了基于非共价相互作用和/或共价键合制备基于 EMISA 的有机、无机或有机/无机杂化纳米诊疗剂的不同方法。展示了荧光成像、核医学成像、光声成像、拉曼成像、计算机断层扫描成像、生物发光成像和磁共振成像的成像实例。本文属于以下分类：诊断工具 > 体内纳米诊断和成像 仿生纳米材料 > 基于肽的结构。
