• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.450-457
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• 2020

In the previous study, there was a big difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene, but there was a problem that could not provide a clue to this problem. Therefore, this study aimed to present a clue to this problem by quantifying and comparing the delivery efficiency after labeling DNA using a fluorescent dye, which was one of the methods for quantifying biomolecules. As a fluorescent dye for labeling, Yo-Pro-1 was used, and the delivery efficiency of the fluorescent dye Yo-Pro-1 and the labeled DNA was compared. The delivery efficiency of Yo-Pro-1 and labeled DNA according to the voltage condition of the digital electroporation system was maximized at 96 V, and the delivery efficiency tended to decrease as the voltage increased further. In the comparison of the delivery efficiency of Yo-Pro-1 and labeled DNA according to the number of voltage application conditions, the delivery efficiency was maximized at the number of 8 voltage application times for both delivery materials, and the delivery efficiency tended to decrease as the number of voltage application increases further. Through the two results, it was confirmed that the delivery efficiency using Yo-Pro-1 in the digital electroporation system represents the delivery efficiency of the system well. In addition, through the results of this study, the difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene shown in the preceding study was not the result of the difference in the delivery efficiency of the delivery material, but it can be predicted to be due to a problem with the expression process of the genetic material that had been delivered.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3061-3063
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• 2016

Exploiting the immune system to abolish cancer growth via vaccination is a promising strategy but that is limited by many clinical issues. For DNA vaccines, viral vectors as a delivery system mediate a strong immune response due to their protein structure, which could afflect the cellular uptake of the genetic vector or even induce cytotoxic immune responses against transfected cells. Recently, synthetic DNA delivery systems have been developed and recommended as much easier and simple approaches for DNA delivery compared with viral vectors. These are based on the attraction of the positively charged cationic transfection reagents to negatively charged DNA molecules, which augments the cellular DNA uptake. In fact, there are three major cellular barriers which hinder successful DNA delivery systems: low uptake across the plasma membrane; inadequate release of DNA molecules with limited stability; and lack of nuclear targeting. Recently, a polysaccharide polymer produced by microalgae has been synthesized in a form of polymeric fiber material poly-N-acetyl glucosamine (p-GlcNAc). Due its unique properties, the F2 gel matrix was suggested as an effective delivery system for immune and gene vaccinations.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.95-98
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• 2007

Polyethylenimine (PEI) has been widely investigated for delivery of DNA into cells. It was previously reported that there were at least two types of cytotoxicity in PEI-mediated gene delivery, immediate and delayed toxicities. PEI-mediated gene delivery protocols use net cationic complexes with an excess of PEI to maintain equilibrium between the complexed and dissociated forms in solution. In this study, toxicity of free PEI or PEI/ DNA complex was investigated. Human embryonic kidney 293 cells were incubated with free PEI or PEI/DNA complex for 4 hrs. Then, the cells were analyzed at 6, 24, 48, and 96 hrs after the incubation. In MTT assay, the viability of the cells incubated with PEI/DNA complex was continuously decreased with time, while that of the cells incubated with free PEI was not. On the contrary, the expression level of the luciferase gene increased gradually along with time. Release of DNAs from the complexes for transcription produces free PEIs in the cells. This process may proceed slowly due to high charge density of PEI and may be related to delayed toxicity. In addition, apoptotic cells were observed only in the cells incubated with the PEI/DNA complex from 24 hrs after the incubation. The results suggest that PEI/DNA complex contributes to the delayed toxicity by inducing apoptosis and that the delayed toxicity may be related to decomplexation of the complexes in the cells.

• Clinical and Experimental Vaccine Research
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• v.13 no.2
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• pp.73-82
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• 2024

DNA cancer vaccines as an approach in tumor immunotherapy are still being investigated in preclinical and clinical settings. Nevertheless, only a small number of clinical studies have been published so far and are still active. The investigated vaccines show a relatively stable expression in in-vitro transfected cells and may be favorable for developing an immunologic memory in patients. Therefore, DNA vaccines could be suitable as a prophylactic or therapeutic approach against cancer. Due to the low efficiency of these vaccines, the administration technique plays an important role in the vaccine design and its efficacy. These DNA cancer vaccine delivery systems include physical, biological, and non-biological techniques. Although the pre-clinical studies show promising results in the application of the different delivery systems, further studies in clinical trials have not yet been successfully proven.

• Journal of the Korean Chemical Society
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• v.43 no.2
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• pp.193-198
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• 1999

The transfection efficiency of plasmid DNA was inspected using multi-cationic polymer, 5, 10, 25 and 50KD polyethylenimine (PEI). The optimal neutralization ratio of PEI/DNA complexes by agarose assay was 1.5-2.0 (nmol/nmol) without much difference in molecular weight of PEI.In vitro transfection assay, most of PEI-mediated plasmid delivery was better compared to the naked DNA. Especially, 25KD PEI at optimal condition gave higher transfection rather than the standard assay of DEAE-dextran or Lipofectin. To enhance the cell targeting delivery, the liposome formulations were introduced using phospholipids. As a result, PC/PE liposomes increased 2-2.5 times of the transfection efficiency of PEI single or PC/PE single delivery, but not the case of 25KD PEI. Moreover, the DOTAP/PE-introduced PEI delivery reduced the transfection of DOTAP/PE single delivery. All these results proved that the PEI can be used not only good transfectants and but also good DNA condensing agents in neutral/anionic liposome for cell targeting delivery.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3665-3670
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• 2013

The R3V6 peptide includes a hydrophilic arginine stretch and a hydrophobic valine stretch. In previous studies, the R3V6 peptide was evaluated as a gene carrier and was found to have low cytotoxicity. However, the transfection efficiency of R3V6 was lower than that of poly-L-lysine (PLL) in N2A neuroblastoma cells. In this study, the transfection efficiency of R3V6 was improved in combination with high mobility group box 1A domain (HMGA). HMGA is originated from the nuclear protein and has many positively-charged amino acids. Therefore, HMGA binds to DNA via charge interaction. In addition, HMGA has a nuclear localization signal peptide and may increase the delivery efficiency of DNA into the nucleus. The ternary complex with HMGA, R3V6, and DNA was prepared and evaluated as a gene carrier. First, the HMGA/DNA complex was prepared with a negative surface charge. Then, R3V6 was added to the complex to coat the negative charges of the HMGA/DNA complex, forming the ternary complex of HMGA, R3V6, and DNA. A physical characterization study showed that the ternary complex was more stable than the PLL/DNA complex. The HMGA/R3V6/DNA complex had a higher transfection efficiency than the PLL/DNA, HMGA/DNA, or R3V6/DNA complexes in N2A cells. Furthermore, the HMGA/R3V6/DNA complex was not toxic to cells. Therefore, the HMGA/R3V6/DNA complex may be a useful gene delivery carrier.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.236.1-236.1
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• 2002

Mucosal administration of drug or therapeutic gene is emerging as a new route of delivery for systemic and local therapeutics. Previously. in situ gelling system has been applied to chemical drug such as acetaminophen. insulin. prostaglandin E1. and clotrimazole. Plasmid DNA has not been delivered in form of in situ gelling vehicles. To improve the intranasal absorption of plasmid DNA. we designed delivery systems composed of provide of in 냐셔 gelling and mucoadhesive polymers. (omitted)

• KSBB Journal
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• v.19 no.5
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• pp.341-347
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• 2004

Several gene delivery therapies are being developed for treatment of serum protein deficiency. EPO is one of the most promising therapeutic agent for this treatment which is currently being investigated in depth. This study has the ultimate purpose of improving the gene delivery system for an increase of red blood cell production. A plasmid DNA was constructed smaller than other plasmids for an increase in penetration into animal cells, and two genes were cloned into each vector as a co-delivery system to express erythropoietin, and interluekin-3 or thrombopoietin, which can act on erythroid cell, thus activating hematopoiesis synergically. This co-delivery system has an advantage of decreasing the labour required for industrial production of DNA vaccine. A new plasmid vector, pVAC, in size 2.9 kb, was constructed with the essential parts from PUC 19 and pSectagB, which is much smaller than other plasmid vector and is the size of 2.9 kb. Co-delivery system was constituted by cloning human erythropoietin with each of human interluekin-3 gene or human thrombopoietin gene into both pVAC and pSectagB. As a result, the transfection efficiency of pVAC was higer than that of pSectagB in vitro, and hematocrit level of the mice injected with pVAC is higher than that of other mice. And co-delivery system, made of several plasmid DNAs, was expressed in vitro.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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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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• v.27 no.9
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• pp.1335-1340
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• 2006

It has been found that a number of diseases are associated with mutations in the mitochondrial DNA. Therapeutic gene delivery to mitochondria has been suggested as a clinical option for these diseases. In this study, we developed a gene carrier to mitochondria by the conjugation of mitochondrial leader peptide (LP) to polyethylenimine (PEI). Mitochondrial LP conjugated PEI (PEI-LP) was synthesized with low molecular weight PEI (2,000 Da, PEI2K). Gel retardation assay showed that PEI2K-LP formed complexes at a 1.0/1 weight ratio. In addition, PEI2K-LP protected DNA from the enzymatic degradation for at least 60 min, while naked DNA was completely degraded within 20 min. PEI2K-LP was compared with LP conjugated high molecular weight PEI (25,000 Da, PEI25K) in terms of toxicity and delivery efficiency. MTT assay showed that PEI2K-LP had much lower cytotoxicity than PEI25K-LP to 293 cells. In addition, cell-free DNA delivery assay showed that PEI2K-LP delivered more DNA to mitochondria at a 1.8/1 weight ratio than naked DNA or PEI. This result suggests that PEI2K-LP may be useful for the development of mitochondrial gene therapy system with lower cytotoxicity.