可逆交联的小尺寸透明质酸纳米载体的设计及肿瘤靶向化疗

Disulfide-based reversibly crosslinked hyaluronic acid (HA) nanocarriers with a diameter of 30-80 nm, constructed from natural hydrophobic molecules modified HA through hydroxyl groups, were utilized for tumor targeted chemotherapy using various type of tumor models. The HA nanoparticles were conveniently prepared via self-assembly of natural HA-HM-LA (HA-hydrophobic molecules-lipoic acid) polymer in the aqueous solution and subsequent crosslinking. Thus obtained nanoparticles bearing several unique advantages: (1) mild and ease preparation by direct dispersion in the aqueous solution, facilitating mass production; (2) excellent biocompatibility and biodegradability; (3) targeting ability irrelevant hydroxyl groups based modification of HA, affording high substitution degree of hydrophobic molecules to obtain small sized nanoparticles, thus leading to enhanced tumor accumulation, penetration and cancer chemotherapy; (4) improved hydrophobicity and disulfide crosslinking density, due to the high content of HM-LA, resulting in efficient encapsulation and in vivo tumor targeted release of anticancer drugs; (5) great potential to target a variety of malignant tumor with high morbidity and mortality regarding the specific binding affinity of HA towards CD44 receptor overexpressed by various cancer cells; (6) simpleness and multi-functionality, proposing high possibility to achieve clinical translation.

本项目通过透明质酸（HA）的羟基修饰天然疏水分子，以构建双硫键可逆交联的小尺寸（30-80 nm）HA纳米载体，用于多种肿瘤模型的靶向化疗。该新型纳米粒子由全天然的透明质酸-疏水分子-硫辛酸（HA-HM-LA）聚合物在水溶液中自组装并交联得到。其具有以下优点：（1）纳米粒子可由聚合物在水溶液中直接分散得到，制备条件温和，有利于大规模生产；（2）纳米粒子具有优异的生物相容性和生物降解性；（3）通过羟基修饰HA不影响其靶向性能，可以引入高取代度的疏水分子，以得到小尺寸纳米粒，促进肿瘤部位的富集和渗透，增强癌症治疗效果；（4）由于疏水分子取代度高，所得纳米粒的疏水性及双硫键交联密度增加，可望同时实现抗癌药物的高效包裹和体内高效肿瘤靶向释放；（5）由于HA可特异性识别CD44受体，该纳米药物有望靶向到高发病率和死亡率的多种恶性肿瘤，实现主动靶向治疗；（6）该纳米药物简单且多功能，可望实现临床转化。

项目针对当前纳米药物普遍面临的制备繁琐、材料安全性低、体内循环稳定性差、肿瘤部位富集量少、细胞内吞效率低及细胞内药物释放缓慢等挑战，创新性地采用透明质酸与天然或生物可降解的疏水分子简单构建了一系列小尺寸的多功能纳米载体，用于小分子抗癌药物和蛋白质药物的高效包载和靶向递送，实现了多种肿瘤模型（皮下乳腺癌、皮下卵巢癌、原位肝癌、乳腺癌PDX模型等）的高效靶向治疗，具有重要的科学意义。主要结果如下：（1）设计构建了小尺寸的双硫可逆交联透明质酸纳米载体，实现了小分子抗癌药物（多西他赛、阿霉素、美登素）和蛋白质药物的高效包载和靶向递送，在三阴性乳腺癌CDX和PDX模型中展示了显著的抗肿瘤活性及较低的毒副作用，具有较大的临床转化潜力。（2）设计构建了基于纯天然分子透明质酸和叶酸的双重靶向纳米药物（阿霉素、索拉菲尼），其制备简单、药物负载量高、安全低毒、且具备优异的长期储存稳定性和冻干再分散性，实现了对皮下SKOV-3卵巢癌和原位SMMC-7721肝癌异种移植小鼠模型的主动靶向治疗，可望拓展转化用于CD44和叶酸受体高表达肿瘤的治疗。（3）设计制备了单抗导向的多功能囊泡表阿霉素纳米药物，在荷皮下SKOV-3卵巢癌裸鼠模型中展示了优异的肿瘤抑制效果，可望拓展用于其它毒素药物的靶向递送，替代抗体药物偶联物。（4）设计制备了双肽修饰的多功能聚合物囊泡，其在提高纳米蛋白体系内涵体逃逸的同时有效保持了细胞靶向性，为蛋白质药物的高效细胞质递送开辟了新途径。本项目所构建的小尺寸多功能透明质酸纳米载药平台制备简单、生物安全性好、兼具稳定性高、靶向递送及细胞内快速释放药物等多重功能、临床转化潜力大，在肿瘤靶向治疗方面具有重要的应用前景。