Genetic and Chemically Programmed Nanoparticles for Prodrug Therapy

描述（由申请人提供）：病毒样颗粒（vlp）代表了针对疾病的最佳表征和最容易定制的纳米结构。它们是x射线晶体学常规分析中最大的组合，也是拥有基因组的最小实体，因此它们在化学和生物学之间占据着独特的地位。我们最近的工作主要集中在28纳米直径的二十面体颗粒上，这些颗粒来自噬菌体Q¿的外壳蛋白。这种结构是在大肠杆菌中重组产生的，产量高，纯度高，对热，可变pH值，有机溶剂和环境条件非常稳定

DESCRIPTION (provided by applicant): Virus-like particles (VLPs) represent the best-characterized and most easily tailored nanostructures for the targeting of disease. They are the largest assemblies to be routinely analyzed by x-ray crystallography, and the smallest entities to possess a genome, and thus they occupy a unique place between the worlds of chemistry and biology. Our recent efforts have focused on the 28 nm diameter icosahedral particle derived from the coat protein of bacteriophage Q¿. This structure, produced recombinantly in E. coli in high yield and purity, is very stable toward heat, variable pH, organic solvents, and conditions of chemical modification. It is also recognized by no specific receptor on mammalian cells, and therefore may be imbued with desired properties by installing functional groups on the outside surface and inside compartment of the capsid. We have developed methods to genetically encode polypeptides on the exterior of Q¿ VLPs while at the same time packaging multiple copies of active enzymes on the inside. The outside groups serve to bind to chosen receptors for the targeting of specific cell types or to display antibodies for the same purpose. The enzymes on the inside can convert benign prodrugs to cytotoxic agents with high catalytic efficiency, while being protected from protease attack and denaturation. We will further develop and enhance the technology to produce these particles, with the goal of more precisely controlling their composition and using more functional components. We will also apply them to proof-of-concept tests of prodrug activation both in vitro and in vivo to determine the scope and limitations of this therapeutic approach. For their eventual clinical application, the consequences of the anti-particle immune response must also be determined. We will therefore conduct the first quantitative assessment of the effects of pre-immunization on the circulation lifetime and biodistribution of this type of nanoparticle, and test sophisticated methods to diminish their immunogenicity and opsonization in the context of these goals. The result of these efforts will be new capabilities in protein nanoparticle design and production, an exciting preclinical evaluation of the merits of prodrug therapy using targeted VLP-packaged enzymes, and a major contribution to the fundamental understanding of nanoparticle targeting and avoidance of opsonization and immunological pathways.