核酸适配体作为一种特异性强、亲和力高的靶向分子，在肿瘤靶向药物传递系统中具有很好的应用前景。然而，多数核酸适配体存在易被体内核酸酶降解、不能直接进入胞内和与其他药物或载体连接时需要复杂的化学修饰的问题。本课题通过引入正四面体DNA纳米笼作为药物载体，将其与核酸适配体靶向分子结合，利用正四面体DNA纳米笼具有保护核酸分子不易被降解的特性以及易于被细胞摄取的能力，弥补核酸适配体作为靶向分子的缺点，从而构建一种基于核酸适配体靶向的适体-正四面体DNA纳米笼药物载体。以多柔比星为模型药物，通过非共价及共价两种方式与适体-正四面体DNA纳米笼结合实现载药，建立基于核酸适配体识别的肿瘤靶向DNA纳米笼递药系统。该系统可通过包含有核酸适配体的DNA纳米笼核酸骨架自组装形成，无需复杂的化学修饰制备步骤，并可通过核酸适配体的靶向作用实现对肿瘤细胞的靶向递药，为化疗药物的肿瘤靶向递送提供一种新的载药系统。

As a specific, high affinity targeting molecule, aptamers are of potential applications in tumor-targeting drug delivery system. However, most aptamers inclined to degradation in vivo by nuclease, not directly penetration into cells and require complex chemical modification for connecting with other drugs or carriers. In this study, tetrahedral DNA cage were introduced as a drug carrier to connect with an aptamer to construct the aptamer-recognized aptamer-tetrahedral DNA cage drug carrier. The properties of tetrahedral DNA cage tend to protect nucleic acid molecule form degradation and easily uptake by cells were utilized to make up the shortcomings of aptamers as targeting molecules. Moreover, Doxorubicin, as a model drug, was linked to the aptamer-tetrahedral DNA cage by non-covalent or covalent ways to establish aptamers recognized tumor-targeting DNA cage drug delivery system. This system can be prepared by self-assemble of the nucleic acid backbone contain aptamers DNA fragment, without complicated steps of chemical modification. Due to the targeting effect of aptamers, this system can achieve targeted drug delivery to tumor cells, which provide a novel drug delivery system for chemotherapy drugs to realize tumor-targeting delivery.