title: Comparison of the cellular transport mechanism of cationic, star-shaped polymers and liposomes in HaCat cells.
abstract: Several biological barriers must be overcome to achieve efficient nonviral gene delivery. These barriers include target cell uptake, lysosomal degradation, and dissociation from the carrier. In this study, we compared the differences in the uptake mechanism of cationic, star-shaped polymer/MMP-9siRNA complexes (β-CD-(D3)7/MMP-9siRNA complexes: polyplexes) and commercial liposome/MMP-9siRNA complexes (Lipofectamine®2000/MMP-9siRNA complexes: liposomes). The uptake pathway and transfection efficiency of the polyplexes and liposomes were determined by fluorescence microscopy, flow cytometry, and reverse transcriptase-polymerase chain reaction. The occurrence of intracellular processing was assessed by confocal laser scanning microscopy. Endosomal acidification inhibitors were used to explore the endosomal escape mechanisms of the polyplexes and lysosomes. We concluded that the polyplexes were internalized by non-caveolae- and non-clathrin-mediated pathways, with no lysosomal trafficking, thereby inducing successful transfection, while the majority of liposomes were internalized by clathrin-dependent endocytosis (CDE), caveolae-mediated endocytosis, and macropinocytosis, and only CDE induced successful transfection. Liposomes might escape more quickly than polyplexes, and the digestion effect of acidic organelles on liposomes was faint compared to the polyplexes, although both complexes escaped from endolysosomes via the proton sponge mechanism. This may be the key aspect that leads to the lower transfection efficiency of the β-CD-(D3)7/MMP-9siRNA complexes. The present study may offer some insights for the rational design of novel delivery systems with increased transfection efficiency but decreased toxicity.
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China; Department of Endocrinology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
authors.forename: Heng-Cong
authors.initials: HC
authors.lastname: Luo
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Yan
authors.affiliation: School of Materials Science and Engineering, School of Chemistry, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Kai-Jin
authors.initials: KJ
authors.lastname: Mai
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Kan
authors.initials: K
authors.lastname: Sun
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Guo-Juan
authors.initials: GJ
authors.lastname: Lao
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, School of Chemistry, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Ren
mesh_terms: D001692:Biological Transport; D002412:Cations; D016923:Cell Death; D004705:Endocytosis / Q000187:drug effects; D011992:Endosomes / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D008081:Liposomes / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D002412:Cations; D008081:Liposomes; D011108:Polymers; D034741:RNA, Small Interfering; D047392:beta-Cyclodextrins; D020780:Matrix Metalloproteinase 9; C031215:betadex
keywords: endocytosis; endolysosomal escape; intracellular trafficking; liposome; β-CD-(D3)7