Drug-based polycations for combination drug-gene delivery

描述（由申请人提供）：需要同时递送药物和基因的改进方法以充分实现药物-基因组合疗法的潜力。我们的长期目标是建立一类新的可生物降解的基因递送载体，其能够在细胞内降解后作为（i）基因递送载体和（ii）活性药理剂发挥双重作用。该提案的目的是设计创新的可生物降解的树枝状BENSpm聚阳离子（BDBP），能够作为基因递送载体和针对癌症中多胺代谢失调的活性抗癌剂双重发挥作用。我们将开发基于阳离子药物N1，N11-bis（ethyl）norspermine（BENSpm）的可生物降解的树枝状聚合物前药，其将有效地将肿瘤坏死因子相关凋亡诱导配体（TRAIL）基因递送到三阴性乳腺癌细胞，然后分解成原始药物BENSpm，从而增强TRAIL的治疗效果。我们推测，如我们的初步数据所示，由于从BDBP释放的BENSpm的协同增强，组合的药物-基因递送将改善TRAIL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枝状BENSpm聚阳离子; 2）确定BDBP与TRAIL组合是否增强人乳腺癌中的抗增殖活性。在目标1中，申请人已经确定可行的合成方法将用于制备在还原性细胞内环境中可降解并且能够释放完整BENSpm的BDBP。在目的2中，BDBP将用于在三阴性乳腺癌细胞MDA-MB-231中递送TRAIL-GFP质粒，并评估细胞内BDBP降解和BENSpm释放对表达的TRAIL-GFP在3-D培养中的抗增殖活性的影响。该方法是创新的，因为递送载体的新颖设计不仅递送治疗基因，而且通过发挥其自身的药理作用来增强治疗基因的活性。该研究将为非病毒基因递送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，具有重要意义。

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.