Development of new injectable, PolyGeneCaP composites for gene therapy

基因治疗的目的是通过提供正常基因来修复或替换受损或缺失的基因来治疗天生患有遗传性疾病的患者。基因治疗的潜在应用包括众所周知的疾病，如血友病、囊性纤维化、肌肉萎缩症、某些类型的癌症和许多其他疾病，目前正在发现有缺陷的基因。目前将健康基因引入受影响患者细胞的程序主要依赖于使用病毒衍生的“载体”，但是人们越来越担心这些媒介还没有得到充分的了解，并且有可能是危险的，甚至是致命的。不幸的是，迄今为止，替代的合成基因传递系统效率低下，而且只取得了非常有限的成功。在这个项目中，我们建议开发一种非病毒传递系统，将特定的健康基因包裹在安全的化学颗粒中。我们计划用一种新方法将它们转化为非常小的“纳米颗粒”（称为GeneCaP），使其完全包围基因，从而保护其不被破坏，并使其更容易进入患者的细胞。为了进一步提高基因进入的效率，这一直是基因治疗的主要问题之一，我们将把GeneCaP放入一种新型的可注射液体（PolyGeneCaP）中。这将被设计成使其快速固化在非常靠近患病器官的地方，然后缓慢降解，释放被包裹的GeneCaP到需要基因发挥作用的细胞附近。本提案将使用的“模型”疾病称为Sly病（粘多糖病VII型），这是一大群溶酶体基因缺陷之一，导致进行性精神和身体残疾，通常在早期致命。疾病的发生是因为有缺陷的基因不能产生一种特殊的溶酶体蛋白，当健康的基因出现时，这种蛋白就会减轻疾病。在这项研究中，我们将首次测量并仔细关联含dna颗粒的特性和这些新的“基因药物”帮助纠正MPS VII疾病的能力，以便能够为一系列遗传疾病制定最佳治疗策略。

The aim of gene therapy is to treat patients who are born with inherited diseases by providing a normal gene to repair or replace the damaged or missing gene. Potential applications of gene therapy include well-known diseases such as haemophilia, cystic fibrosis, muscular dystrophy, some types of cancer and many other disorders where the defective genes are now being identified. Current procedures for the introduction of healthy genes into the cells of affected patients have relied primarily on the use of virus-derived 'carriers', but there is growing concern that these agents are not yet well enough understood and have the potential to be dangerous, even fatal. Unfortunately, alternative synthetic gene-delivery systems have thus far been inefficient and have had only very limited success. In this project we are proposing to develop a non-viral delivery system that has a specific healthy gene entrapped within a safe chemical particle. We plan to use a new method to convert these into very small 'nanoparticles' (called GeneCaP) that fully surround the gene and therefore protect it from breakdown and also enable it to get more readily into the patient's cells. To increase further the efficiency of gene entry, which has been one of the major problems in gene therapy, we will place the GeneCaP into a novel liquid (PolyGeneCaP) which can be injected. This will be designed so that it will rapidly solidify very close to the diseased organ and then degrade slowly, releasing the encased GeneCaP adjacent to the cell where the gene is needed to function. The 'model' disease which will be used in this proposal is called Sly Disease (Mucopolysaccharidosis Type VII), one of a large group of lysosomal gene defects which result in progressive mental and physical disability and are usually fatal at an early age. Illness occurs because the defective gene is unable to produce a particular lysosomal protein, which when restored in the presence of the healthy gene alleviates the disease. In this study we will, for the first time, measure and carefully correlate the properties of the DNA-containing particles and the ability of these new 'gene-drugs' to help correct the MPS VII disease, in order to be able to develop the optimal treatment strategies for a range of genetic diseases.