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

描述（由申请人提供）：使用siRNA作为任何选择的基因的有效抑制剂的前景可以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的疗法的主要障碍是通常不能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，亚50纳米（s50）胶囊，能够将大分子药物有效地细胞内递送到靶组织和细胞。这是通过将大分子药物压缩在完全由蛋白质或肽配体形成的亚50 nm胶囊壳中来实现的，以利用受体介导的小窝内吞作用来高效地跨细胞膜转运到细胞内区室。在我们的初步研究中，我们证明了在小鼠中以低剂量水平将针对B-半乳糖苷酶的纳米封装siRNA有效递送至B-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，我们在这项拟议研究中的第一个目标需要评估和优化siRNA纳米胶囊制剂，包括1）通过采用常规寡核苷酸的成功研究结果来开发和表征用于肿瘤靶向的siRNA纳米胶囊制剂，2）比较纳米胶囊递送与体外脂质体递送，和3）使用模型系统在体内比较纳米胶囊递送与修饰骨架siRNA的裸递送。在关注治疗效果的第二个目标中，我们建议使用裸鼠中的人前列腺癌原位异种移植模型，比较针对酪蛋白激酶2（最近验证的癌症靶标）的修饰骨架siRNA的纳米胶囊递送与裸递送。如果成功的话，我们希望这项工作的完成将为与NIH和/或药物开发人员合作提供一个坚实的框架，以推进封装的siRNA疗法。在基因水平上操纵疾病病理学可以导致治愈，而不仅仅是对症治疗。因此，预期被诊断患有晚期疾病的患者的生活质量和存活率将用靶向siRNA治疗剂显著改善。将siRNA疗法推向市场的关键途径是有效的药物递送;潜在地，这项研究将推动沿着这条道路取得沿着重大进展。

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 B-galactosidase to B-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.