Development of the next generation of lipid nanoparticles for gene therapy

脂质纳米粒(LNPs)是药物递送、功能基因组学和其他生物技术和医学应用的革命性工具。他们即将实现个性化医学的梦寐以求的应用之一：癌症等疾病的个性化基因治疗。对导致肿瘤生长的“无赖”基因的了解很多，但要有效地关闭或“沉默”这些基因，仍然存在许多重大障碍。最有希望的基因治疗方法是利用短的双链RNA(SiRNA)，其序列允许它与癌症基因的信使RNA结合，之后自然的细胞机制将其降解。在细胞内传递后，siRNAs已显示出在体外沉默特定基因的能力。然而，在体内使用siRNA需要复杂的递送技术，因为“裸露的”siRNA在循环中迅速分解，不会在疾病部位聚集，也不能穿透靶细胞膜到达其细胞内作用部位。将siRNA包裹在LNP中可以保护siRNA在血流中不被降解，并通过内吞作用使siRNA在细胞内内化。然而，在增加LNPs的实际使用方面仍有大量工作要做。LNP siRNA系统的纳米结构及其所包含的五种不同脂质成分的功能作用尚不清楚，阻碍了开发稳定、可针对不同组织、易于制造并满足监管要求的下一代系统的努力。在这个项目中，我们将使用计算机模拟和生物物理表征来研究不同成分在决定LNPs的结构、大小、靶向特性和内体释放机制中的作用。我们将在新的LNPs的设计和制造中测试我们的知识。这将改进LNPs的合理设计技术，极大地扩大其作为抗癌药物和功能基因组学工具的用途，并通过我们的合作伙伴Precision NanoSystems实现这两项技术的商业化，以及开发针对特定癌症形式的药物。

Lipid nanoparticles (LNPs) are a revolutionary tool for drug delivery, functional genomics and other applications in biotechnology and medicine. They are on the verge of enabling one of the dream applications of personalized medicine: individual gene therapy in diseases such as cancer. Knowledge of the "rogue" genes responsible for tumour growth is substantial but there remains a number of significant obstacles to effectively turning these genes off or "silencing" them. The most promising gene therapy approach utilizes short pieces of double stranded RNA (siRNA) whose sequence allows it to bind to the cancer gene's messenger RNA, after which a natural cellular mechanism degrades it. Following intracellular delivery siRNAs have demonstrated abilities to silence specific genes in vitro. However, the use of siRNA in vivo requires sophisticated delivery technologies, since "naked" siRNAs are rapidly broken down in the circulation, do not accumulate at disease sites and cannot penetrate target cell membranes to reach their intracellular sites of action. Encapsulating siRNA in an LNP protects the siRNA from degradation in the bloodstream, and enables the internalization of the siRNA within the cell via endocytosis. However, considerable work remains to increase the practical use of LNPs. The nanostructure of the LNP siRNA systems and the functional roles of the five different lipid components they contain are not well understood, impeding efforts to develop next generation systems that are stable, can be targeted to different tissues, are straightforward to manufacture, and meet regulatory requirements. In this project, we will use computer modelling and biophysical characterization to investigate the role of the different components in determining the structure, size, targeting properties and the endosomal release mechanism of LNPs. We will test our knowledge in the design and manufacture of new LNPs. This will lead to improved rational design technology for LNPs that will greatly expand their use as anti-cancer drugs and functional genomics tools, with extensive opportunities for commercialization of both technology, through our partner Precision NanoSystems, and the development of drugs for specific forms of cancer.