Optimal Hydrophobicity of Lipoid Gene Delivery Agents

描述(申请人提供)：阳离子类脂化合物在体外和体内通常用于将DNA输送到细胞以表达外源基因的目的。许多临床试验表明，这些药物在基因治疗方面很有希望，但基于脂质的递送仍然不如替代病毒载体有效。然而，与最初的配方相比，已经有了很大的改进，类脂制剂与修饰的病毒相比具有重要的安全优势。Avanti Lipids一直在销售一种不同寻常的阳离子类脂，这种类阳离子类脂基于天然脂质磷脂酰胆碱，在体外表现出低细胞毒性。通过简单的化学修饰，磷脂酰胆碱转化为阳离子化合物，与DNA形成络合物，是有效的转染剂。这些化合物最初是由西北大学开发的，最近被发现在混合物中具有非常强的协同作用；例如，两种这样的化合物混合在一起比单独使用两种化合物要有效得多。此外，最佳的组成取决于条件和电池。这些发现指出了一种全新的方法来增强基因(可能还有药物)的传递，这表明这些分子的疏水部分可能对这些阳离子类脂制剂的疗效至关重要。这项建议的目的是考察各种阳离子磷脂酰胆碱，这些阳离子磷脂酰胆碱具有不寻常的疏水部分，在任何其他阳离子类脂类中都很难或不可能合成。这些脂类将由Avanti合成，并在西北大学进行转基因活性测试和相关物理性质的表征。活性比现有化合物高50倍的化合物或混合物有望立即商业化，尽管人们预计会发现活性更高的化合物。所有提出的方法都已在以前发表过。

DESCRIPTION (provided by applicant): Cationic lipid-like compounds are commonly used in vitro and in vivo to deliver DNA to cells for the purposes of expressing exogenous genes. A number of clinical trials have indicated the promise of these agents for gene therapy, however lipid-based delivery remains less effective than the alternative viral vectors. Nevertheless, vast improvements have been made over the initial formulations and lipid-like agents have an important safety advantage over modified viruses. Avanti Lipids has been marketing an unusual category of cationic lipoids that are based on the natural lipid phosphatidylcholine and which, in vitro exhibit low cell toxicity. Through a simple chemical modification, the phosphatidyl cholines are converted to cationic compounds that form complexes with DNA and are effective transfection agents. These compounds, originally developed at Northwestern University, have recently been found to give very strong synergy in mixtures; for example, a mixture of 2 such compounds is much more effective than either compound separately. Furthermore, the optimal composition depends on conditions and cells. These findings point to an entirely new approach for enhancing gene (and probably drug) delivery, suggesting that the hydrophobic portions of these molecules maybe critical for the efficacy these cationic lipid-like agents. The aim of this proposal is to survey a variety of cationic phosphatidylcholines that have unusual hydrophobic moieties that would be difficult or impossible to synthesize in any other cationic lipoid class. The lipids will be synthesized by Avanti and tested for transfection activity and characterized with respect to relevant physical properties at Northwestern. Immediate commercialization is anticipated for compounds or mixtures with 50X higher activity than current compounds, although the expectation is that compounds with even higher activity will be discovered. All proposed methods have been previously published.