• Journal of Pharmaceutical Investigation
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• 제30권1호
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• pp.1-12
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• 2000

Gene therapy is a method for the treatment of diseases with introducing the gene-engineered materials into a patient with gene-deficiency disease (e.g. cystic fibrosis) or cancer to produce a therapeutic protein in a patient's cells. Successful gene therapy requires establishing both gene expression systems and delivery systems. Viral and non-viral vectors have been used for gene delivery. Viral vectors have a high transfection efficiency, but are limited in relations to issues of safety, toxicity and immunogenecity. Non-viral vectors are easy to prepare and relatively safe. However, non-viral vectors have a low transfection efficiency. Cationic liposomes are the most available among non-viral vectors. Cationic liposomes have been used to transfect cells both in vitro and in vivo experiments. Besides, several formulations containing cationic lipid are being used in clinical trials in cases of cystic fibrosis or cancer. A crucial subject to the further development of gene delivery vectors will be a long-term gene expression with following characteristics; protecting and deliverying DNA efficiently, non-toxic and non-immunogenic, and easy to produce in large scale.

• KSBB Journal
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• 제13권4호
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• pp.418-423
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• 1998

Cellular transfections with cationic liposomes are widely empolyed for gene and oligonucleotide transfer in vitro because of their safety and ease of use. However, they still suffer from the low transfection efficiency comparing with viral vectors. Substantial effort shave been focused on increasing transfection efficiency by supplementing the liposome/DNA complexes(lipoplex) with various components. In this work, we tired three kinds of supplements, Poly-L-lysine(PLL), transferrin and a mixture of anionic lipids(PS/PE/PC), to study their effects on gene transfer yield and gene expression efficiency. PLL, a polycationic polymer, enhanced gene transfer yield by 3 times but the gene expression efficiency was increased only by 1.5 times. this result implies that PLL can enhance the transfection efficiency mainly by increasing the rate of outermembrane transport of lipoplex into the cells. On the other hand, transferrin which can facilitate the gene transfer via ligand-receptor interaction gave not only increased gene transfer yield but also enhanced gen expression efficiency by 2.8 times. Transferrin seems to contribute to the escape of plasmid from endosomes through ligand-receptor recycle mechanism. When the cells were treated with a mixture of anionic lipids for 3 hours before the transfection, gene transfer yield was slightly decreased but the gene expression efficiency was enhanced by 1.9 times. This is presumably due to the accelerated liposome-plasmid dissociation by the anionic lipids, and the increased delivery of plasmid to the nucleus. According to these results, it is clear that the supplementation to ameliorate transfection efficiency with cationic liposomes should be contrived in the direction of increasing delivery of plasmid.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.735-742
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• 2013

Peptide nucleic acids (PNAs) that bind to complementary nucleic acid sequences with extraordinarily high affinity and sequence specificity can be used as antisense oligonucleotides against microRNAs, namely antagomir PNAs. However, methods for efficient cellular delivery must be developed for effective use of PNAs as therapeutic agents. Here, we demonstrate that antagomir PNAs can be delivered to hepatic cells by complementary DNA oligonucleotide and cationic liposomes containing galactosylated ceramide and a novel cationic lipid, DMKE (O,O'-dimyristyl-N-lysyl glutamate), through glycoprotein-mediated endocytosis. An antagomir PNA was designed to target miR-122, which is required for translation of the hepatitis C virus (HCV) genome in hepatocytes, and was hybridized to a DNA oligonucleotide for complexation with cationic liposome. The PNA-DNA hybrid molecules were efficiently internalized into hepatic cells by complexing with the galactosylated cationic liposome in vitro. Galactosylation of liposome significantly enhanced both lipoplex cell binding and PNA delivery to the hepatic cells. After 4-h incubation with galactosylated lipoplexes, PNAs were efficiently delivered into hepatic cells and HCV genome translation was suppressed more than 70% through sequestration of miR-122 in cytoplasm. PNAs were readily released from the PNA-DNA hybrid in the low pH environment of the endosome. The present study indicates that transfection of PNA-DNA hybrid molecules using galactosylated cationic liposomes can be used as an efficient non-viral carrier for antagomir PNAs targeted to hepatocytes.

• Journal of Pharmaceutical Investigation
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• 제33권3호
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• pp.209-213
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• 2003

The objective of this study was to construct the pegylated liposomes containing plasmid DNA with optimal encapsulation efficiency. Plasmid DNA $(pGL2\;clone\;753,\;{\sim}6\;kb)$ was encapsulated by the freeze/thawing method into liposomes composed of 1-palmitoyl-2-oleyl-sn-glycerol-3-phosphocholine (POPC), didodecyl dimethyl ammonium bromide (DDAB), distearoylphosphatidyl ethanolamine polyethylene glycol 2000 (DSPE-PEG 2000) and DSPE-PEG 2000-male-imide. The liposomes containing plasmid DNA were then extruded through two stacked polycarbonate filters with series of different pore sizes to control the liposome size. The plasmid DNA entrapped in the liposomes was separated from free plasmid DNA by Sephadex CL-4B column chromatography. The decreased pore size of polycarbonate filters resulted in the decreased size of liposomes. The encapsulation efficiency was markedly affected by the cationic lipid (DDAB) concentration, but to a low degree by the size of liposomes and by the amount of plasmid DNA.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.788-794
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• 2015

Cationic liposomes have been actively used as gene delivery vehicles despite their unsatisfactory efficiencies because of their relatively low toxicity. In this study, we designed novel heterodimeric peptides as nonviral gene delivery systems from TAT and NLS peptides using cysteine-to-cysteine disulfide bonds between the two. Mixing these heterodimeric peptides with DNA before mixing with lipofectamine resulted in higher transfection efficiencies in MCF-7 breast cancer cells than mixing unmodified TAT, NLS, and a simple mixture of TAT and NLS with DNA, but did not show an adverse effect on cell viability. In gel retardation assays, the DNA binding affinities of heterodimeric peptides were stronger than NLS but weaker than TAT. However, this enhancement was only observed when heterodimeric peptides were premixed with DNA before being mixed with lipofectamine. The described novel transfection-enhancing peptide system produced by the heterodimerization of TAT and NLS peptides followed by simple mixing with DNA, increased the gene transfer efficiency of cationic lipids without enhancing cytotoxicity.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.651-656
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• 2012

Cationic immunoliposomes were prepared by conjugation of Fab' fragments of the recombinant humanized monoclonal antibody (HuCC49) against tumor-associated glycoprotein (TAG)-72 to sterically unilamella liposomes. The cationic immunoliposomes are composed of cationic lipid (O,O'-dimyristyl-N-lysyl aspartate, DMKD), cholesterol, and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide(polyethyleneglycol)$_{2000}$] (DPPE-PEG-maleimide) with a molar ratio of 0.5:0.47:0.03. Plasmid DNA was effectively condensed by addition of transferrin (Tf) during the formation of anti-TAG-72 PEG-immunolipoplexes (PILPs). These anti-TAG-72 PILPs were able to adhere to the surface of TAG-72-overexepressing LS174T human colon cancer cells more effectively than conventional liposomes, thereby facilitating gene delivery in vitro. Furthermore, intravenous administration of the anti-TAG-72 PILPs into the tumor-carrying mice exhibited efficient localization of the reporter gene in the tumor tissues.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.516-521
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• 2005

Drug delivery to the lymphatic system may be important in terms of the treatment with lymphatic involvement, such as tumor metastases and immunization. Especially, drug transport via the intestinal lymphatics after oral administration has been attracted lots of interests. The purpose of this study was to prepare cyclosporin A (CSA)-loaded liposomes, with different characteristics, and evaluate their mucoadhesivity. Three liposome preparations were formulated: cationic stearylamine liposomes (SA-Lip), anionic phosphatidylserine liposomes (PS-Lip), Polymer (chitosan)-coated liposomes (CS-Lip), and characterized. The liposome preparations were found to be spherical in shape, with PS-Lip being the smallest. The liposome preparations exhibited entrapment efficiencies in the order: PS-Lip $(52.5{\pm}2.9%)$ > SA-Lip $(48.8{\pm}3.3%)$ > CS-Lip $(41.7{\pm}4.2%)$. Finally, mucoadhesive tests were carried out using rat intestine, with SA-Lip (67%) showing the best adhesive rate of the three preparations (PS-Lip: 56%, CS-Lip: 61%). These results suggest that a positive charge on the surface of drug carriers may be an important factor for the intestinal drug delivery.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권1호
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• pp.57-62
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• 2002

Cationic liposomes complexed with DNA have been extensively utilized for the delivery of reporter or therapeutic genes both in culture and in vivo. We investigated and determined the optimum conditions of a cationic liposome, composed of dimethyldioctadecy-lammonium bromide (DDAB) and dioleoyl phosphati-dylethanolamine UOPE), mediated a reporter plasmid expressing luciferase into insect cell lines (Sf-21 and Bm-N) and silkworm larvae. Together the data demonstrated that Bombyx mori nuclear polyhedrosis virus (BmNPV) genomic DNA (128 kb) was successfully transfected into Bm-5 cells using this liposome. These results suggest that DDAB/DOPE liposome will be useful as delivery agents for gene transfer to insect cells both in vitro and in vivo.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.425.3-426
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• 2002

Cationic lipids have been used as one of the major components for making most promising non-viral gene delivery systems. whereas sodium cholate. an edge activator has been used as a surfactant in making ultradeformable and ultraflexible liposomes called Transfersomes. Using both a cationic lipid, DOTAP and sodium cholate. a newly formulated ultradeformable cationic liposome has been prepared. The average particle size of this formulation was approximately 80nm. (omitted)

• 폴리머
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• 제29권3호
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• pp.277-281
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• 2005

비바이러스성 DNA 전달체 중에서 최근 양이온성 고분자와 양이온성 리피드들은 많이 연구되어 왔다. 본 연구에서는 비바이러스성 유전자 전달체로서 양이온성 고분자인 폴리에틸렌이민(PEI)을 리피드에 수식하여 더 효과적인 전달체를 제조하고자 하였다. 새로운 양이온성 리피드(PEI-DSPE)는 1,2-디아실-sn-글리세로-3-포스포에탄올아민(DSPE)과 PEI를 이용하여 고수율로 합성하였다. 1,2-디스테아로일-sn-글리세로-3-포스포콜린(DSPC), L-$\alpha$-포스파티딜콜린(소이-하디드로제네티드) (HSPC), 콜레스테롤(CHOL) 및 합성된 PEI-DSPE를 이용하여 리포좀을 제조하였다. 리포좀 제조는 리피드 함량에 대해 양이온성이 도입된 PEI-DSPE의 양을 증가시키며 수행하였다. 제조된 리포좀의 크기는 PEI-DSPE의 첨가량이 증가할수록 감소하였으며 리포좀의 표면전하 또한 양의 값으로 증가됨을 관찰할 수 있었다. PEI-DSPE 양적 변화에 따라 제조된 리포좀을 이용하여 DNA의 복합체 형성에 관한 결과 사용된 리포좀의 함량이 증가할수록 DNA와의 복합체 형성이 용이함을 전기영동 및 형광 측정을 통해 관찰할 수 있었으며 형성된 복합체가 사용된 리포좀 함량이 증가할수록 양이온적 성질이 증대됨을 관찰할 수 있었다. 그러므로 본 연구에서 합성한 PEI-DSPE를 사용하여 제조된 리포좀이 유전자 전달체로서의 가능성을 갖고 있음을 확인할 수 있었다.