RGD-Polymer Targeting Plasmid to Angiogenic Endothelium

描述(由申请人提供)： 将设计一种新的靶向血管生成内皮细胞的聚合物载体。阳离子聚合物聚乙烯亚胺(PEI)将通过亲水性聚乙二醇间隔物(PEI)与avb31avb5整合素结合RGD-4C多肽ACDCRGDCFC偶联。这种设计的载体将用于抗新生血管病质粒的输送。与正常组织相比，血管生成内皮细胞中α-v-β3和α-v-β5整合素的显著高表达提供了对实体瘤的特异性靶向，PEI凝聚DNA并具有内向性，从而保护并将抗血管生成质粒DNA输送到靶细胞。此外，聚乙二醇间隔物增加了载体的溶解度，降低了PEI的毒性。此外，这种聚合物载体是非免疫原性的，实用上可以很容易地大规模生产。使用PEI-PEG-RGD载体，初步数据表明，质粒DNA具有很高的特异性和对靶细胞的转染性。将产生包含内源性血管生成抑制物、溶解的Flt-1和Fik-1受体以及新构建的治疗性基因pDHFR-P53的质粒体。经过广泛的鉴定、体外研究，将采用大鼠恶性胶质瘤和小鼠Lewis肺癌动物模型(局部和全身给药途径)与载体。许多针对肿瘤血管的内源性抑制剂已经被研究，它们在动物身上的全身给药可以抑制肿瘤的生长和转移。然而，重组蛋白的生产已被证明是困难的，需要高剂量才能有效治疗。此外，全身蛋白质疗法包括重复注射以延长治疗时间，这不仅给药不便，而且成本高昂。利用这些内源性血管生成抑制物进行基因治疗可以缓解这些问题。这些结果将是有价值的资产，为使用抗血管生成基因治疗癌症提供基因传递标准。

DESCRIPTION (provided by applicant): New polymer carrier targeting to angiogenic endothelial cells will be designed. The cationic polymer, polyethylenimine (PEI) will be conjugated with the avb31avb5 integrin binding RGD-4C peptide, ACDCRGDCFC via hydrophilic polyethylene glycol (PEG) spacer. This designed carrier will be used for the delivery of antiangiognesis plasmids. The significant over expression of alpha-v-Beta3 and alpha-v-Beta5 integrins in angiogenic endothelial cells provides specific targeting of solid tumors compared to normal tissue, PEI condenses DNA and is endosomotropic, thereby protecting and delivering antiangiogenic plasmid DNA into target cells. In addition, the PEG spacer increases the solubility of the carrier and reduces PEI toxicity. Furthermore, this polymeric carrier is nonimmunogenic and for practical purposes can be easily mass-produced. Using the PEI-PEG-RGD carrier, preliminary data shows high specificity and transfection of plasmid DNA to the target cells. Plasmid constructs will be generated containing the endogeneous angiogenic inhibitors, solublized Flt-1 and FIk-1 receptors and the newly constructed therapeutic gene, pDHFR-p53. After extensive characterization, in vitro studies, rat malignant glioma, and murine lewis lung carcinoma animal models will be used (local and systemic delivery routes) with the carrier. A number of endogenous inhibitors targeting tumor vasculature have been studied and their systemic administration in animals suppresses the growth of tumor and metastases. However, production of recombinant proteins has proven to be difficult and high doses are required for effective treatment. In addition, systemic protein therapy includes repeated injections for prolonged treatment, which is inconvenient for administration and costly. Gene therapy, utilizing these endogenous angiogenesis inhibitors, can alleviate these problems. The results will be valuable assets to provide criteria for gene delivery in the treatment of cancer using antiangiogenesis genes.