Synthetic vectors for pH-targeted gene delivery

用于 pH 靶向基因递送的合成载体

基本信息

批准号：
7001188
负责人：
David Oupicky
金额：
$ 18.01万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-01-01 至 2007-09-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Selective tumor delivery of therapeutic genes is instrumental to the success of numerous cancer gene therapy protocols. The objective of this research proposal, which is a key step in our long-term goal to develop safe and efficient vectors for systemic human cancer gene therapy, is to prepare polyplexes capable of selective surface presentation of targeting ligands in response to small physiologically relevant decrease of pH. Well defined, end-functionalized copolymers of N-isopropylacrylamide and 1-vinylimidazole, which display pH-induced globule-to-coil phase transition at body temperature, will be synthesized by RAFT polymerization, conjugated with PEG, protamine, and targeting ligands, and used to prepare polyplexes with plasmid DNA and oligonucleotides. We hypothesize that pH-triggered phase transition will display targeting ligands selectively at slightly acidic pH and permit pH-selective cellular uptake. The phase state-controlled tropism of polyplexes will be investigated by analyzing pH-dependent binding of biotin-containing polyplexes to immobilized avidin and by measuring the levels of pH-dependent cellular uptake of non-specifically-binding and integrin- and asialoglycoprotein-binding polyplexes in cell culture. To our knowledge, this is the first use of stimuli-responsive polymers to control tropism of synthetic self-assembly vectors for gene delivery. While preliminary results demonstrating the feasibility of controlling surface properties of polyplexes by the phase state of the stimulus-responsive copolymers are presented, the modulation of ligand binding by pH needs to be clearly demonstrated to establish the feasibility of this approach. Funding through the NIBIB R21 mechanism will allow us to test the validity of our hypothesis and establish a design platform for further development of polyplexes with stimuli-responsive tropism. The polyplexes with pH-controlled tropism, proposed here, will be exploited in the development of gene delivery vectors that recognize and selectively display targeting ligands in slightly acidic extracellular pH of many solid tumors; thus minimizing the need for tumor-specific ligands.

描述（由申请人提供）：治疗基因的选择性肿瘤递送对众多癌症基因治疗方案的成功有用。这项研究建议的目的是我们长期为全身性人类癌基因治疗开发安全有效的向量的重要步骤，是为能够选择靶向配体以响应pH pH的小小的生理相关降低而进行选择性表面呈现靶向配体的双流线。 N-异丙基丙烯酰胺和1-乙烯咪唑的定义明确，最终功能化的共聚物，它们在体温下显示pH诱导的小球到线圈相变，将通过筏聚合，与PEG，PEG，PROTAMINE和PROTAMINE和PORTATION LIGANDS，以及与Polyplexe polyplexs and Olig dnae con偶联合成。我们假设pH触发的相变会在略微酸性pH下选择性地显示靶向配体，并允许pH选择性的细胞摄取。通过分析含有生物素的多聚体的pH依赖性结合与固定化抗生化素的pH依赖性结合，并测量非特异性结合和亚乳糖蛋白结合蛋白结合蛋白结合蛋白结合的pol依赖的细胞摄取水平，从而研究了多流线的相位控制的趋势。据我们所知，这是刺激响应性聚合物首次使用用于控制基因递送的合成自组装媒介的向向主义。尽管提出了通过刺激反应性共聚物的相位状态来控制多聚链体的表面特性的可行性，但需要清楚地证明，通过pH对配体结合的调节以确定这种方法的可行性。通过Nibib R21机制的资金将使我们能够检验假设的有效性，并建立一个设计平台，以进一步开发具有刺激反应性的偏移症。在此处提出的具有pH控制的pH传递性的多链体将在基因递送载体的发展中被利用，这些基因递送载体识别并选择性地显示了许多实体瘤的细胞外pH中的靶向配体；从而最大程度地减少了对肿瘤特异性配体的需求。