Drug-based polycations for combination drug-gene delivery

描述(申请人提供)：需要改进同时输送药物和基因的方法，以充分发挥药物-基因联合疗法的潜力。我们的长期目标是建立一类新型的可生物降解的基因递送载体，能够在细胞内降解后作为(I)基因递送载体和(Ii)活性药物的双重功能。该方案的目的是设计新型的可生物降解的树枝状BENSpm聚阳离子(BDBP)，能够同时作为基因传递载体和活性抗癌剂来靶向癌症中调节失调的多胺代谢。我们将开发基于阳离子药物N1，N11-双(乙基)去甲精胺(BENSpm)的可生物降解的树状大分子前药，该药物将有效地将肿瘤坏死因子相关的凋亡诱导配体(TRAIL)基因转移到三重阴性乳腺癌细胞，然后分解为原始药物BENSpm，从而增强TRAIL的治疗效果。我们推测，根据我们的初步数据，由于BDBP释放的BENSpm的协同增强作用，药物-基因联合传递将提高TRAIL的抗癌活性。我们的总体目标将通过追求两个具体目标来实现：1)合成可生物降解的树突状BENSpm聚阳离子；2)确定BDBP与TRAIL联合应用是否增强了人类乳腺癌的抗增殖活性。在目标1中，申请人已确定为可行的合成方法将用于制备可在还原的细胞内环境中降解并能够释放完整的BENSpm的BDBP。目的2利用BDBP将TRAIL-GFP载体导入三阴性乳腺癌细胞MDA-MB-231中，观察BDBP在细胞内的降解和BENSpm的释放对TRAIL-GFP在三维培养中抗增殖活性的影响。这种方法是创新的，因为它设计了新颖的递送载体，不仅可以递送治疗基因，还可以通过发挥其自身的药理作用来增强治疗基因的活性。这项研究具有重要意义，因为它将为药物-基因同时传递的非病毒基因传递系统建立一个广泛适用的设计范式，从而改善基因治疗策略的结果。

DESCRIPTION (provided by applicant): Improved methods to simultaneously deliver drugs and genes are needed to fully realize the potential of drug-gene combination therapies. Our long-term goal is to establish a new class of biodegradable gene delivery vectors capable of functioning dually as (i) gene delivery vectors and (ii) active pharmacologic agents after intracellular degradation. The objective of this proposal is to design innovative biodegradable dendritic BENSpm polycations (BDBP) capable of functioning dually as a gene delivery vector and an active anticancer agent targeting dysregulated polyamine metabolism in cancer. We will develop biodegradable dendrimer prodrugs based on a cationic drug N1,N11-bis(ethyl)norspermine (BENSpm) that will efficiently deliver tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene to triple negative breast cancer cells and then decompose into the original drug BENSpm, thus augmenting the therapeutic effect of TRAIL. We hypothesize that the combined drug-gene delivery will improve TRAIL anticancer activity due to synergistic enhancement by BENSpm released from BDBP, as suggested by our preliminary data. Our overall objective will be achieved by pursuing two specific aims: 1) synthesize biodegradable dendritic BENSpm polycations; 2) determine whether BDBP combined with TRAIL enhances antiproliferative activity in human breast cancer. In aim 1, a synthetic methodology, which has been established as feasible by the applicant will be used to prepare BDBP that are degradable in a reducing intracellular environment and capable of releasing intact BENSpm. In aim 2, the BDBP will be used to deliver TRAIL-GFP plasmid in triple-negative breast cancer cells, MDA-MB-231, and to evaluate the effect of intracellular BDBP degradation and BENSpm release on the antiproliferative activity of expressed TRAIL-GFP in 3-D culture. The approach is innovative because of the novel design of delivery vectors that not only deliver therapeutic genes but also augment the activity of the therapeutic gene by exerting its own pharmacologic effect. The proposed research is significant because it will establish a widely applicable design paradigm for non-viral gene delivery systems for simultaneous drug-gene delivery and thus it will improve outcome of gene therapy strategies.