The development of non-viral gene delivery systems, with the capacity to overcome most of the biological barriers facing gene delivery, is challenging. We have developed peptide-based, multicomponent, non-viral delivery systems, incorporating: a bombesin peptide ligand (BBN(6–14)), to selectively target the gastrin releasing peptide receptor (GRPR); oligoarginine peptides (hexa- (R₆) and nona-arginine (R₉)), for plasmid DNA (pDNA) condensation; and GALA, to facilitate endosome escape. The uptake and endosome escape efficiency of bombesin/oligoarginine and bombesin/oligoarginine/GALA fusion peptides for oligonucleotide delivery was evaluated in terms of their complex size, cellular uptake, endosome escape, and cellular toxicity. Complex size and cell uptake studies demonstrated that the nona-arginine/bombesin delivery system was more efficient at condensing and delivering pDNA into PC-3 prostate cancer cells compared to the hexa-arginine/bombesin delivery system. Further, competition with free bombesin peptide, and comparative uptake studies in Caco-2 cells, which express GRPR at a lower level, suggested that GRPR contributes to the targeted uptake of this system. The addition of GALA into the nona-arginine/bombesin-based system further increased the pDNA cellular uptake at all tested N/P ratios; facilitated endosomal pDNA release; and had limited effects on cell viability. In conclusion, the delivery system combining BBN(6–14) with nona-arginine and GALA had optimal characteristics for the delivery of pDNA into the GRPR overexpressing cell line PC-3.

具有克服基因传递所面临的大多数生物障碍的能力的非病毒基因传递系统的开发是具有挑战性的。我们已经开发出基于肽的多组分非病毒递送系统，该系统包括：蛙皮素肽配体（BBN（6–14）），以选择性靶向胃泌素释放肽受体（GRPR）；寡精氨酸肽（六（R ₆）和_九精氨酸（R ₉）），用于质粒DNA（pDNA）缩合；和GALA，以促进内体逃逸。通过寡核苷酸递送的蛙皮素/寡精氨酸和蛙皮素/寡精氨酸/ GALA融合肽的摄取和内体逸出效率，根据它们的复杂大小，细胞摄取，内体逸出和细胞毒性来评估。复杂的大小和细胞摄取研究表明，与六精氨酸/ Bombosin递送系统相比，九精氨酸/ Bombosin递送系统在将pDNA浓缩和递送到PC-3前列腺癌细胞中更为有效。此外，与游离蛙皮肽肽的竞争以及在较低水平表达GRPR的Caco-2细胞中的比较摄取研究表明，GRPR有助于该系统的靶向摄取。将GALA添加到基于九氨酸/精氨酸的系统中后，在所有测试的N / P比率下，pDNA细胞的摄取进一步增加。促进内体pDNA释放；并且对细胞活力的影响有限。总之，结合了BBN（6-14）与九氨精氨酸和GALA的递送系统具有将pDNA递送至GRPR过表达细胞系PC-3的最佳特性。