Development of new injectable, PolyGeneCaP composites for gene therapy

基因治疗的目的是通过提供一个正常的基因来修复或替换受损或缺失的基因，从而治疗先天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、肌肉营养不良、某些类型的癌症和许多其他疾病，目前正在识别这些缺陷基因。目前将健康基因导入受影响患者细胞的程序主要依赖于使用病毒衍生的“携带者”，但越来越多的人担心，这些因素还没有得到足够的了解，有可能是危险的，甚至是致命的。不幸的是，到目前为止，替代的合成基因传递系统一直效率低下，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。我们计划使用一种新的方法将这些转化为非常小的纳米颗粒(称为GeneCaP)，这些纳米颗粒完全围绕在基因周围，从而保护基因免受破坏，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放入一种新型的液体(PolyGeneCaP)中，该液体可以注射。这将是这样设计的，它将在非常接近患病器官的地方迅速固化，然后缓慢降解，释放被包裹的GeneCaP，靠近该基因发挥功能所需的细胞。这项建议中将使用的“模型”疾病被称为Sly病(粘多糖症III型)，这是一大组溶酶体基因缺陷之一，会导致进行性的精神和身体残疾，通常在幼年时是致命的。疾病的发生是因为有缺陷的基因不能产生特定的溶酶体蛋白，当在健康基因存在的情况下恢复时，这种蛋白可以缓解疾病。在这项研究中，我们将首次测量并仔细关联含有DNA的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，以便能够开发出一系列遗传病的最佳治疗策略。

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.