活体内microRNA响应的诊疗一体化纳米探针的构建与应用

Cancer is one of the most dangerous diseases threatening human life and health. Its early diagnosis and suitable treatment can reduce the mortality rate. Therefore, it is essential to develop highly sensitive and efficient methods for early cancer diagnosis and treatment against the threat of human cancer. The purpose of this project is intended to develop all-in-one nanoprobes containing fluorescence probes for early cancer detection and stimuli-responsive drug delivery vectors for precise cancer treatment. Upconversion nanoparticles and near infrared fluorescent materials were complexed to produce fluorescence nanoprobes with near infrared excitation and emission light to specifically identify tumor tissues of subcutaneous tumor or breast cancer mice via target molecule in vivo. MicroRNA-controlled drug carrier system, integrated with DNAzyme amplification technology without the help of polymerase or cutting enzyme, was explored to highly release drugs at disease sites for gene therapy and chemotherapy. Furthermore, pharmacodynamic mechanism was investigated via pharmacological assays. Based on the development of fluorescence probes and drug delivery carriers, all-in-one nanoprobes for simultaneous cancer diagnosis and treatment in vivo were constructed, using microRNA as a source to activate fluorescent probes and trigger drug release. These strategies would provide new theory evidences and technical means for clinical measurement and treatment of solid tumors.

癌症是威胁人类生命健康的最重大疾病之一，高灵敏的早期诊断方法和高效的治疗手段可降低其致死率。本项目拟结合荧光探针和应激药物缓释载体构建诊疗一体化纳米探针，实现活体内癌症部位的早期诊断和精准治疗。制备上转化纳米材料与近红外荧光材料的复合材料，获得具有近红外激发光和发射光的荧光探针，建立皮下、乳腺癌小鼠模型，修饰靶向分子，实现活体内肿瘤组织的特异性检测。开发癌症相关microRNA响应的智能药物缓释载体，实现基因药物和化学药物对肿瘤的协同治疗；探究在无聚合酶和剪切酶的生理环境中 microRNA循环放大体系，最大化释放药物，增强疗效；并考察病理学参数，揭示药效机制。整合荧光探针和药物缓释载体的研究基础，深入探索以microRNA为触发源同时激活荧光探针和控制药物释放的诊疗一体化纳米探针，以期同步实现microRNA相关疾病的检测和治疗，为临床医学中实体瘤的检测和治疗提供新的理论依据和技术手段。

癌症的早期诊断和有效治疗可以有效提高存活率，开发高灵敏、高特异性诊断方法及实时药效监测手段可帮助医生和病人进行癌症的早期诊断和精准治疗。该项目的研究成果包括：（1）制备了尺寸均一的磷酸钛纳米粒子，通过表面修饰不同的靶向基团如适配体、多肽、叶酸分子等，实现对于癌细胞的特异性识别作用。对磷酸钛纳米粒子进行金属化后，通过金属离子电化学信号可以实现对癌细胞的高灵敏，高特异性检测。（2）构建了用于药物靶向传输和荧光实时监测的多功能磷酸钛纳米载体。该纳米载体通过叶酸分子可以有效提高药物摄入量，增强药效，引起细胞凋亡产生ROS，激活载体表面荧光探针，通过荧光强弱有效监测药物药效。（3）开发了microRNA响应的药物传输及药效监测的多功能磷酸钛载体。该载体可以有效提高非水溶性药物KS-01在细胞内的摄入量，并通过癌细胞内microRNA作为激发源有效刺激药物释放，极大提高药物治疗效果，同时引起细胞产生caspase-3激活载体表面荧光，实现对KS-01靶向传输、可控释放和药效评估。（4）合成了近红外光激发和发射的上转换纳米材料作为荧光探针，用于活体内肿瘤成像及药效监测。该上转换纳米荧光材料具有很好的生物相容性，对其进行修饰后可以有效靶向肿瘤部位，用药后通过近红外荧光强度实现对caspase-3表达水平的检测。该项目的开展发展了一系列用于癌细胞检测、靶向治疗、药效监测的多功能纳米载体，为临床癌症的诊断和治疗提供了新的检测手段及药效评估方法，为临床用药提供理论依据。该项目的研究成果已完成项目预期的研究目标。在项目执行期间，项目负责人以第一作者和通讯作者身份在国际主流期刊上发表学术论文5篇。目前已协助培养毕业硕士研究生1名，现仍在读博士生和硕士生各1名。