International Journal of Nanomedicine (Dec 2017)
Polyethyleneimine-capped silver nanoclusters for microRNA oligonucleotide delivery and bacterial inhibition
Abstract
Chunyuan Du,1,* Haibo Yan,2,* Jichao Liang,1 Ailing Luo,1 Lingqian Wang,1 Jing Zhu,1 Huayu Xiong,3 Yong Chen1 1Hubei Province Key Laboratory of Biotechnology of Chinese Traditional Medicine, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei University, Wuhan, 2Department of Internal Medicine, Shandong Medical College, Linyi, 3Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University, Wuhan, China *These authors contributed equally to this work Abstract: Efficient and safe nonviral gene delivery systems are a prerequisite for the clinical application of therapeutic genes. In this paper, polyethyleneimine-capped silver nanoclusters (PEI-AgNCs) were prepared for the purpose of microRNA (miRNA) delivery. The resultant PEI-AgNCs were characterized by a photoluminescence assay and transmission electron microscopy. A cytotoxicity assay showed that PEI-AgNCs exhibit relatively low cytotoxicity. Interestingly, PEI-AgNCs were confirmed to transfect miRNA mimics more effectively than PEI in HepG2 and 293A cells. In this regard, hsa-miR-21 or hsa-miR-221 mimics (miR-21/221m) were transported into HepG2 cells by using PEI-AgNCs. The miR-21/221 expression was determined post-transfection by quantitative real-time polymerase chain reaction. Compared with the negative control, PEI-AgNCs/miR-21/221m groups exhibited higher miR-21/221 levels. In addition, AgNCs endow PEI with stronger antibacterial activity, and this advantage provided PEI-AgNCs the potential to prevent bacterial contamination during the transfection process. Furthermore, we showed that PEI-AgNCs are viable nanomaterials for plain imaging of the cells by laser scanning confocal microscopy, indicating great potential as an ideal fluorescent probe to track the transfection behavior. These results demonstrated that PEI-AgNCs are promising and novel nonviral vectors for gene delivery. Keywords: gene delivery, silver nanoclusters, polyethylenimine, cell imaging, antibacterial activity