载阿霉素金纳米粒凝胶治疗肝癌的机制及疗效研究

Transarterial chemoembolization therapy is an important therapeutic method for patients with unresectable liver tumor and embolic material is a key factor affecting the efficacy of interventional therapies for liver cancer. We have successfully developed drug-loading temperature-sensitive nanogels and have already applied them in the embolization of liver cancer in our previous experimental study. However, the nanopaticles are not radiopaque, which need to be mixed with a contrast agent to achieve X-ray visibility. Further studies shows that the drug-loaded radiopaque embolization material could not only increase the controllability of embolization during operation, but also be beneficial to the follow-up and observation after operation. Temperature sensitive p(N-isopropylacrylamide-co-acrylic acid) modified gold nanoparticles has good radiopaque visibility and embolization efficiency. The problem further to be solved is whether the modified Dox-GNPs/Nanogels shows its radiopaque visibility and realizes the sustained release of chemotherapeutic drugs at the same time. According to this project, it is suggested that Dox-GNPs/Nanogels can realize self-radiopaque , embolization and drug controlled release. So we're going to develop Dox-GNPs/Nanogels, and we intend to 1) develop a new X-ray visible nano-embolic agent, 2) investigate the embolic properties in vitro model(determine in vitro its embolic properties), and 3) evaluate its efficacy, safety and X-ray visibility in embolization for liver cancer in animal models . This study will provide theoretical and practical bases for clinical application of radiopaque embolic materials, and thus improving the effectiveness of transcatheter therapies for liver cancer.

介入栓塞术是治疗中、晚期肝癌的重要手段，栓塞材料是影响肝癌介入疗效的关键因素。前期研究已证实，负载化疗药物的纳米凝胶可用于肝癌模型介入治疗研究，但还存在不能够自显影、需要同造影剂混合使用的问题。进一步研究发现，载药型自显影栓塞材料既可以增加术中栓塞可控性，又有利于术后随访观察。温敏型聚聚合物修饰的金纳米粒水分散体PNA@GNP具有良好的自显影性、栓塞有效性，有待需要进一步解决的问题是改良后载阿霉素金纳米粒水凝胶-Dox-GNPs/Nanogels能否实现自显影的同时又可以实现化疗药物的缓释。本项目据此提出，Dox-GNPs/Nanogels可实现显影-栓塞-药物缓释。我们拟研制一种新型自显影性纳米凝胶，以期体外验证其生物安全性，体内验证其对肝癌动物模型的疗效、安全性和可随访性。本项目将为新型自显影栓塞材料的临床应用提供理论基础和实践依据，提高肝癌介入治疗效果。

经导管栓塞治疗是临床治疗中、晚期肝癌的首选方法。栓塞材料是影响肝癌介入疗效的关键因素。前期研究已证实，负载化疗药物的纳米凝胶可用于肝癌模型介入治疗研究，但还存在不能够自显影、需要同造影剂混合使用的问题。基于此，本研究制备了一种将化疗药物与显像相结合的栓塞剂，即阿霉素-聚丙烯酸修饰金纳米粒/温敏纳米凝胶（GNP@D-PNAx）。材料表征结果显示GNP@D-PNAx具有较好的温敏特性和流动性，GNP@ D-PNAx具有良好好的X线衰减效果，有利于术中成像和术后评价。肾动脉栓塞实验结果显示GNP@D-PNAx可导致栓塞肾脏完全缺血性坏死，具有永久性血管阻塞的能力。VX2荷瘤兔肝动脉栓塞实验结果显示，与生理盐水、碘油，空白GNP@PNAx等栓塞剂相比，GNP@D-PNAx可显著抑制肿瘤生长和转移、促进肿瘤凋亡和坏死。同时，药物代谢结果显示GNP@D-PNAx负载阿霉素在肿瘤内可达到较好的缓释效果。此外，免疫组化结果显示GNP@D-PNAx能够降低栓塞后瘤内MMP-9，HIF-1α、CD31及VEGF表达，改善肿瘤缺氧和免疫抑制微环境。为进一步评估GNP@D-PNAx对肿瘤免疫微环境的影响，本研究同期加用C57鼠Hepa1-6皮下瘤模型。结果显示GNP@D-PNAx组瘤内CD8+淋巴细胞浸润增多，表明GNP@D-PNAx能产生较好的抗肿瘤免疫反应。通过细胞毒性实验及栓塞后兔肝肾功能检测显示GNP@D-PNAx具有良好的生物安全性。基于以上结果，GNP@D-PNAx可实现显影-栓塞-药物释放，其自显影特性、生物相容性、栓塞安全有效性得到良好的验证，为医用介入栓塞材料的研制提供新思路、新途径。