低温可分离的生物降解性微针贴片传递纳米疫苗用于持久性癌症免疫治疗

Cancer still leads to high mortality worldwide. Traditional therapy are usually limited to cure metastatic tumors, and they are prone to cause side effects. Regarding these problems, immunotherapy has become a crucial strategy for the treatment of metastatic tumors owing to its specificity, intelligence, low toxicity, immune memory and other advantages. However, the current delivery system of immunotherapeutics to antigen presenting cells have not been able to achieve these goals efficiently and sustainably. Based on active immunotherapy, including application of tumor vaccine and reduction of tumor immunosuppression, the cationic tumor protein, RNA vaccine that expresses tumor protein, and siRNA that inhibits signal transducer and activator of transcription formed the co-delivery nanovaccine through microfluidic technology. Based on abundant immune cells in the skin layer, a old-sensitive separable biodegradable microneedle patch encapsulating the above nanovaccine was used for intradermal injection. The biodegradable poly(sulfamethazine ester urethane) was fabricated as the needle section. The temperature-sensitive material poly(N-isopropylacrylamide) was fabricated as the connection between the needle section and the patch section. Polyvinyl alcohol was fabricated as the patch section. After slow degradation of the needle section, the nanovaccine could be released for a long term and taken up by the antigen-presenting cells in the skin, thereby triggering the tumor immune response and inhibiting metastatic tumors persistently.

癌症仍然是造成人类死亡率较高的疾病。传统疗法通常难以治愈转移性肿瘤，并且易导致副作用。对于这些问题，免疫治疗因其针对性、智能性、低毒性、记忆性等优势成为转移性肿瘤治疗重要的策略，但是目前免疫治疗剂向抗原提呈细胞的传输体系尚无法高效而持久地达到该目的。本项目基于应用肿瘤疫苗和降低肿瘤免疫抑制这两方面主动免疫治疗，将阳离子化的肿瘤蛋白、表达肿瘤蛋白的RNA疫苗、抑制信号传导及转录激活蛋白的小干扰RNA通过微流控技术制成共传递纳米疫苗。基于皮肤层中大量的免疫细胞，采用低温可分离的生物降解性微针贴片负载上述纳米疫苗进行皮内注射，由生物降解性的聚磺胺二甲嘧啶酯氨基甲酸酯制造针头部分，首次引入了温度敏感性材料聚(N-异丙基丙烯酰胺)作为针头部分和贴片部分的连接，由聚乙烯醇制造贴片部分。经过针头部分在皮内缓慢降解，纳米疫苗能够长期释放并且被皮内的抗原提呈细胞摄取，引发肿瘤免疫反应，持久性地抑制转移性肿瘤

近年来，核酸疫苗作为对抗肿瘤或病毒的主动免疫治疗工具，引起了广泛关注。然而，它们在体内的不稳定性以及难以单独被抗原提呈细胞摄取的事实成为了其应用的主要限制，尤其体现于RNA疫苗。在本项目中，申请人在不同阶段先后探索了一系列核酸疫苗的递送系统，并且拓展了其应用领域，包括对抗肿瘤和新冠病毒。具体地，一方面基于皮内层中大量抗原提呈细胞的存在，申请人首先设计并合成了分别负载不同类别免疫佐剂的核酸纳米疫苗，实验结果显示这些纳米疫苗均具备粒径小、粒径分布均匀、结构稳定、和形貌规则等优势，重要的是其能够保护所负载的核酸疫苗并且实现其在抗原提呈细胞的高效摄取以及相关抗原的表达。然后，申请人在已具备的用于皮内疫苗注射的微针技术上进一步发展了新型可分离的生物降解性/生物缓控释微针贴片，针尖部分可以负载核酸纳米疫苗，并且具备足够的机械强度刺穿皮肤角质层。在皮内注射后，这些微针贴片的针尖部分能够缓慢降解，实现核酸纳米疫苗在皮内层的长期释放，进而触发持久的对抗转移性肿瘤或新冠病毒的体液免疫和细胞免疫效应；另一方面基于皮下引流淋巴结的存在，申请人设计并合成了能够原位转化核酸纳米疫苗的功能化凝胶。在皮下注射后，此凝胶不仅维持了核酸疫苗的稳定性，还能够缓慢转化核酸纳米疫苗释放到引流淋巴结并被其中的抗原提呈细胞摄取，进而触发持久的对抗原发性和转移性肿瘤的体液免疫和细胞免疫效应。以上策略分别实现了这些疾病有效治疗的目的，避免了多次注射。