共载化疗药和磁性纳米粒缓释栓塞微球的可视化多模式抗肝癌策略研究

Traditional transcatheter arterial chemoembolization(HCC) for hepatocellular carcinoma is likely to cause toxic side effects and high recurrence rate. Meanwhile, the conventional embolic agents are rarely visible in the magnetic resonance imaging (MRI), and also unable to track the precise location and distribution of embolic agents during TACE. Magnetized Drug-Eluting Beads is a new targeted dosage form, which can be visible in MRI. They can enhance the anti-tumor effect of chemotherapeutic drugs with microwave treatment. Electrospraying technology is an electrohydrodynamic process in which a spray of monodisperse micro-sized droplets is formed under a high-voltage electric field. Based on this, this study will prepare a sustained-release embolic microsphere system containing adriamycin and Fe3O4 nanoparticle, which controlled particle size of microspheres by electrospraying method, supplemented by in vitro microwave hyperthermia to achieve multi-modal combination therapy of hepatocellular carcinoma. Our pre-experiment found that sustained-release embolic microspheres were successfully prepared by electrospraying method and adriamycin could sustain release for 26 days, while supplemented by microwave hyperthermia can significantly improve the anti-tumor effect. This project intended to further determine and optimize the preparation process and physical and chemical properties of the embolic microspheres. Co-incubation of cells and microspheres was used to clarify the effect of co-loading microspheres on the cell apoptosis and the cell viability. The orthotopic animal model of hepatocellular carcinoma was established, and embolization was performed for interventional therapy, to determine the effect of arterial embolization, chemotherapy and microwave hyperthermia to produce synergistic anti-hepatocellular carcinoma. This study will provide new ideas and new methods for the safe and efficient embolization of solid tumors.

传统的经导管肝动脉化疗栓塞术治疗肝细胞肝癌易引起全身毒副作用且复发率较高，而栓塞材料粒径不均且无法实现栓塞可视化。载药磁性微球是一种新型靶向给药剂型，其不仅能实现可视化栓塞治疗，并且可结合体外微波热疗杀伤肿瘤。电喷雾乳化法可通过高压电将液体单分散成微米级的雾滴，利用这种方法可以制备粒径均匀的微球。基于此，本研究将以电喷雾乳化法制备可控粒径的共载阿霉素和Fe3O4纳米粒栓塞微球，辅以体外微波热疗实现肝癌的多模式联合治疗。前期研究证实该微球能够缓释阿霉素持续杀伤肝癌细胞达26天，且辅以微波热疗能显著提高抗肿瘤疗效。本项目拟进一步确定并优化该栓塞微球制备的处方工艺和理化性质；明确该微球辅以微波热疗对肝癌细胞抗肿瘤效果；建立原位肝癌模型动物，开展肿瘤的栓塞介入治疗研究，确定肿瘤动脉栓塞、化学药物治疗以及微波热疗能够产生协同抗肝癌作用。本实验为实体肿瘤的安全高效栓塞治疗提供新的思路和方法。

经肝动脉化疗栓塞术作为目前临床中晚期肝癌的常用疗法，仍存在肿瘤反应差、残留的肿瘤组织容易进展和复发等问题，栓塞微球粒径不均且无法实现栓塞可视化。前期研究发现四氧化三铁纳米粒介导的磁热不仅能够有效提高递送效率并改善化疗药物在肿瘤内的分布，从而增强对肿瘤细胞的杀伤作用，还可以实现微球在磁共振成像下的可视化。基于此，本项目创新性地将四氧化三铁纳米粒引入到肝癌介入化疗栓塞治疗体系中来全面改善TACE整体治疗效能，并开展了以下研究工作：（1）通过高压电喷雾技术制备了共载阿霉素和Fe3O4纳米粒的单分散明胶微球（ADM/Fe3O4-MS），对其处方工艺和理化性质进行了全面的探索，通过改变电压、针头内径、注射流速、明胶浓度和戊二醛浓度五个参数实现了ADM/Fe3O4-MS的可控制备，制备得到的ADM/Fe3O4-MS平均粒径为217.7 ± 57.4 μm，阿霉素包载量为1.7 ± 0.1%，四氧化三铁纳米粒的包载量为4.9 ± 0.6%，同时微球能实现长期缓慢释放阿霉素，且微球具有超顺磁性以及良好的磁热效应，并在T2加权成像中显示出良好的成像效果；（2）体外细胞实验显示相比其他微球，在磁热介导的情况下，ADM/Fe3O4-MS展现出更强的抗肿瘤作用，明显提升了肿瘤细胞杀伤作用，且进一步证实了微波介导的热疗通过激活铁死亡来放大ADM/Fe3O4-MS的抗肿瘤效果；（3）利用VX2兔原位肝癌模型在体内层面对其栓塞性能和抗肿瘤作用进一步进行了确认，研究结果也证实了ADM/Fe3O4-MS能够实现稳定的栓塞作用，且磁热介导下的ADM/Fe3O4-MS具有更为卓越的抗肿瘤作用，展现出了更强的原位肿瘤抑制能力。在本项目的支持下，本项目相关研究成果累计发表SCI研究论文3篇，影响因子均大于5，其中2篇项目申请人以通讯作者身份发表。本研究为新型肝癌栓塞剂的制备提供了新的思路和科学依据。