血红蛋白基纳米铂药的肿瘤化学动力学治疗研究

Chemodynamic therapy (CDT) is an emerging technology for cancer oxidation therapy, and the combination of CDT and chemotherapy would hold originality and tremendous promise for enhanced cancer therapy and overcome drug resistance of tumor. However, the safety and efficiency of combination of CDT and chemotherapy are limited by drug resistance and hypoxic microenvironment of tumor, co-delivery carrier materials, and adaptive antioxidant regulation of tumor cells. Hence, in this project, a biosafe tumor acid-responsive hemoglobin-based nano-self-assembled carrier are prepared and reduction-responsive platinum(IV) pro-drug is further conjugated. For the first time, we realize the controllable co-delivery of CDT reagent and platinum drug by using a hemoglobin-based nano-carrier for combination cancer CDT and chemotherapy. Hemoglobin is used to improve tumor oxygenation to block drug efflux; At the same time, reduction-responsive platinum(IV) pro-drug can stimulate the production of H2O2 and eliminate glutathione to activate the apoptosis pathway and alleviate the platinum drug detoxification mechanism, resulting in enhanced efficacy of combination therapy and cisplatin resistance reversal. The cancer treatment effect, synergistic mechanism and toxicity of CDT/chemotherapy based on the hemoglobin-based platinum nanoparticles are in-depth studied, providing experimental basis for solving the scientific problems including controllable co-delivery of CDT reagents and chemotherapy drugs, efficiently combating cisplatin resistance and delivery safety.

化学动力学治疗(CDT)是一项新兴的肿瘤氧化治疗手段，将其与传统化疗联合用于肿瘤的增强治疗以克服化疗耐药性极具原创性和应用前景。然而肿瘤CDT与化疗联合的安全性和有效性受到肿瘤耐药性及乏氧微环境、共传输载体材料类型、肿瘤细胞自身适应性抗氧化调节等问题的限制。本项目拟制备生物安全性好的酸响应性血红蛋白基纳米自组装体并键合化学还原敏感型四价铂前药，创新性地实现血红蛋白基CDT试剂和铂药的可控共传输用于肿瘤联合CDT与化疗。利用血红蛋白改善肿瘤的乏氧微环境来阻断药物外排；并通过化学还原敏感型四价铂前药同时刺激H2O2产生和清除谷胱甘肽，激活细胞凋亡通路并缓和铂药解毒机制，实现增强的协同治疗效果并彻底逆转肿瘤铂药耐药性。深入研究血红蛋白基纳米铂药的联合CDT/化疗效果、作用机理以及毒性，为CDT试剂/化疗药物共传输、肿瘤铂药耐药性有效逆转以及安全性等关键科学问题奠定研究基础。

化学动力学治疗(CDT)是一项新兴的肿瘤氧化治疗手段，将其与传统化疗联合用于肿瘤的增强治疗以克服化疗耐药性极具原创性和应用前景。然而肿瘤CDT与化疗联合的安全性和有效性受到肿瘤耐药性及乏氧微环境、共传输载体材料类型、肿瘤细胞自身适应性抗氧化调节等问题的限制。.本项目制备血红蛋白基纳米颗粒并用于包封化疗药物，创新性地实现血红蛋白基CDT试剂、化疗药物和治疗气体（氧气、一氧化碳）的可控共传输用于肿瘤联合CDT/气体治疗/化疗。我们利用蛋白质自聚集技术和自组装技术成功制备血红蛋白基纳米载体并担载化疗药物。通过1H NMR，MALDI-TOF-MS，ESI-MS，SDS-PAGE，透射电镜等手段表征了材料的合成和载体的制备。在体外，证明了血红蛋白基载药纳米颗粒能够可控的向肿瘤细胞内递送气体，并且在肿瘤细胞高H2O2浓度环境下进行Fenton反应，生成活性氧自由基，破坏细胞内氧化还原平衡和线粒体结构。通过MTT实验证明血红蛋白基载药纳米颗粒能够提高对耐药细胞的杀伤能力。同时，使用Western Blot技术证明血红蛋白基载药纳米颗粒处理耐药细胞后，HIF-a、P-gp等耐药蛋白表达降低，Bax和caspase-3等凋亡蛋白的表达增加，验证了血红蛋白基载药纳米颗粒逆转耐药的机理。我们进一步建立人源性肿瘤组织（肝癌）异种移植模型、小鼠阿霉素耐药乳腺癌癌(MCF-7/ARD)的异位植瘤裸鼠动物模型和小鼠顺铂耐药肺腺癌(A549/DDP)的异位植瘤裸鼠动物模型，测定血药浓度，证明血红蛋白基载药纳米颗粒能够延长药物半衰期。通过荧光成像，HPLC或ICP-MS方法测定药物在各组织器官的分布，证明血红蛋白基载药纳米颗粒能够提高药物在肿瘤的蓄积。抑瘤实验证明了相比于小分子化疗药物，血红蛋白基纳米载药纳米颗粒能够更有效的抑制耐药肿瘤的生长。同时，我们通过检测给药期间小鼠体重变化，治疗结束后脏器损伤和小鼠生存率等证明了血红蛋白基载药纳米颗粒具有良好的安全性。本项目为治疗气体/CDT试剂/化疗药物共传输、肿瘤耐药性有效逆转以及安全性等关键科学问题奠定研究基础。