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

描述（由申请人提供）：使用sirna作为任何选择基因的有效抑制剂的前景可能为许多难治性疾病提供新的治疗方法。然而，成功开发基于siRNA的疗法的一个主要障碍是，通常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递送到细胞中。GeneSegues开发了一种新的递送技术，即亚50纳米（50）胶囊，能够在细胞内将大分子药物有效地递送到目标组织和细胞。这是通过将大分子药物压缩在低于50纳米的完全由蛋白质或肽配体组成的胶囊壳中来实现的，以利用受体介导的腔泡内吞作用，通过细胞膜高效运输到细胞内室。在我们的初步研究中，我们证明了纳米封装siRNA对？-半乳糖苷酶？-半乳糖苷酶-(+)肿瘤低剂量小鼠。为了在这些有希望的早期发现的基础上，我们在这项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)开发和表征用于肿瘤靶向的siRNA纳米胶囊配方，通过适应传统寡核苷酸成功研究的结果，2)比较纳米胶囊的体外递送与脂质体递送，以及3)使用模型系统比较纳米胶囊的递送与体内修饰骨架siRNA的裸递送。在第二个关注治疗效果的目标中，我们建议在裸鼠中使用人类前列腺癌的原位异种移植模型，比较纳米胶囊递送与针对酪蛋白激酶2（一种最近验证的癌症靶点）的修饰骨干siRNA的裸递送。如果成功的话，我们期望这项工作的完成将为与NIH和/或药物开发商合作提供一个坚实的框架，以推进封装siRNA疗法的发展。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，靶向siRNA疗法有望显著改善晚期疾病患者的生活质量和生存。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取得重大进展。

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.