College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Nanoscale. 2018 Apr 26;10(16):7511-7518. doi: 10.1039/c7nr08558c.
DNA has emerged as a biocompatible biomaterial that may be considered for various applications. Here, we report tumor cell-specific aptamer-modified DNA nanostructures for the specific recognition and delivery of therapeutic chemicals to cancer cells. Protein tyrosine kinase (PTK)7-specific DNA aptamer sequences were linked to 15 consecutive guanines. The resulting aptamer-modified product, AptG15, self-assembled into a Y-shaped structure. The presence of a G-quadruplex at AptG15 was confirmed by circular dichroism and Raman spectroscopy. The utility of AptG15 as a nanocarrier of therapeutics was tested by loading the photosensitizer, methylene blue (MB), to the G-quadruplex as a model drug. The generated MB-loaded AptG15 (MB/AptG15) showed specific and enhanced uptake to CCRF-CEM cells, which overexpress PTK7, compared with Ramos cells, which lack PTK7, or CCRF-CEM cells treated with a PTK7-specific siRNA. The therapeutic activity of MB/AptG15 was tested by triggering its photodynamic effects. Upon 660 nm light irradiation, MB/AptG15 showed greater reactive oxygen species generation and anticancer activity in PTK7-overexpressing cells compared to cells treated with MB alone, those treated with AptG15, and other comparison groups. AptG15 stemmed DNA nanostructures have significant potential for the cell-type-specific delivery of therapeutics, and possibly for the molecular imaging of target cells.
DNA 已成为一种生物相容性生物材料，可考虑用于各种应用。在这里，我们报告了肿瘤细胞特异性适体修饰的 DNA 纳米结构，用于特异性识别和向癌细胞递送治疗化学品。蛋白酪氨酸激酶（PTK）7 特异性 DNA 适体序列与 15 个连续的鸟嘌呤相连。得到的适体修饰产物 AptG15 自行组装成 Y 形结构。通过圆二色性和拉曼光谱证实了 AptG15 中存在 G-四链体。通过将光敏剂亚甲蓝（MB）加载到 G-四链体作为模型药物来测试 AptG15 作为治疗药物的纳米载体的用途。生成的负载 MB 的 AptG15（MB/AptG15）与缺乏 PTK7 的 Ramos 细胞或用 PTK7 特异性 siRNA 处理的 CCRF-CEM 细胞相比，对过表达 PTK7 的 CCRF-CEM 细胞表现出特异性和增强的摄取。通过触发其光动力效应来测试 MB/AptG15 的治疗活性。在 660nm 光照射下，与单独用 MB 处理的细胞、用 AptG15 处理的细胞以及其他比较组相比，MB/AptG15 在过表达 PTK7 的细胞中产生了更多的活性氧物种并具有更强的抗癌活性。AptG15 衍生的 DNA 纳米结构具有针对特定细胞类型的治疗药物递送的巨大潜力，并且可能适用于靶细胞的分子成像。
