Tumor-targeted delivery of siRNA via sub-50 nanometer capsules

描述(由申请人提供)：使用siRNAs作为任何选择的基因的有效抑制剂的前景可能为许多顽固性疾病提供一种新的治疗方法。然而，基于siRNA的治疗成功发展的一个主要障碍是普遍无法使用临床相关方法在体内以稳定和细胞特异性的方式将siRNA输送到细胞中。GeneSegues开发了一种新的给药技术，亚50纳米(S50)胶囊，能够有效地将大分子药物输送到靶组织和细胞。这是通过将大分子药物压缩在完全由蛋白质或多肽配体组成的亚50 nm胶囊外壳中实现的，以利用受体介导的空泡内吞作用高效地通过细胞膜向细胞内转运。在我们的先导研究中，我们展示了在低剂量水平下，针对β-半乳糖苷酶的纳米囊化siRNA有效地输送到β-半乳糖苷酶(+)肿瘤。为了建立在这些有希望的早期发现的基础上，我们在这项拟议的研究中的第一个目标是评估和优化siRNA纳米胶囊配方，包括1)通过将成功的研究结果与传统寡核苷酸相适应来开发和表征用于肿瘤靶向的siRNA纳米胶囊配方，2)在体外比较纳米胶囊递送和脂质体递送，以及3)使用模型系统比较纳米胶囊递送和体内修饰主干siRNA的裸递送。在关注治疗效果的第二个目标中，我们建议使用人前列腺癌裸鼠原位异种移植模型，比较纳米胶囊传递和裸露传递针对酪蛋白激酶2的修饰骨架siRNA的作用，酪蛋白激酶2是最近被证实的癌症靶点。如果成功，我们预计这项工作的完成将为与美国国立卫生研究院和/或药物开发商合作推进封装的siRNA疗法提供一个坚实的框架。在基因水平上操纵疾病病理可以导致治愈，而不仅仅是对症治疗。因此，通过有针对性的siRNA疗法，被诊断为晚期疾病的患者的生活质量和存活率有望显著改善。将siRNA疗法推向市场的关键途径是有效的药物输送；这项研究可能会推动这条道路上的重大进展。

DESCRIPTION (provided by applicant): The prospect of using siRNAs as potent inhibitors to any gene of choice may provide a new therapeutic approach for many intractable diseases. However, a major impediment to successful development of siRNA-based therapies has been the general inability to deliver siRNA into cells in a stable and cell-specific manner in vivo using clinically relevant methods. GeneSegues has developed a novel delivery technology, sub-50 nanometer (s50) capsules, capable of efficient intracellular delivery of large molecule drugs to target tissues and cells. This is achieved by compressing large molecule drugs in sub-50 nm capsule shells formed entirely of protein or peptide ligands, to take advantage of receptor-mediated caveolar endocytosis for highly efficient transport across the cell membrane to intracellular compartments. In our pilot studies, we demonstrate effective delivery of nanoencapsulated siRNA against ?-galactosidase to ? -galcatosidase-(+) tumors at low dosing levels in mice. To build upon these promising early findings, our first aim in this proposed research entails assessing and optimizing siRNA nanocapsule formulations, including 1) developing and characterizing siRNA nanocapsule formulations for tumor-targeting by adapting results from successful research with conventional oligos, 2) comparing nanocapsule delivery to liposomal delivery in vitro, and 3) comparing nanocapsule delivery to naked delivery of modified-backbone siRNA in vivo using a model system. In a second aim focusing on therapeutic efficacy, we propose to compare nanocapsule delivery vs. naked delivery of modified-backbone siRNA against Casein Kinase 2, a recently validated cancer target, using an orthotopic xenograft model of human prostate cancer in nude mice. If successful, we expect that completion of this body of work would provide a solid framework for partnering with NIH and/or drug developers to progress encapsulated siRNA therapies forward. Manipulation of disease pathology at the gene level can lead to a cure, not just symptomatic treatment. Consequently, quality of life and survival of patients diagnosed with advanced disease would be expected to improve significantly with targeted siRNA therapeutics. The critical path to bringing siRNA therapeutics to market is effective drug delivery; potentially, this research will drive significant progress along that path.