• KSBB Journal
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• 제22권4호
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• pp.179-184
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• 2007

본 연구는 특정 아미노산들로 구성된 단위체가 반복되는 형태를 가지는 반복단위 단백질을 유전공학적으로 합성하는 방법들과 응용사례들을 소개하고 있다. 유전공학적 합성법은 단위체의 반복횟수를 정확하게 제어하면서 인식부위의 제한을 없애서 원하는 단백질만을 발현할 수 있도록 발전해왔으며, 최근 소개된 RDL과 CCM 방법에 의하여 가능해졌다. 반복단위 단백질의 응용사례로는 대표적으로 ELP, SLP, Prolamin 등의 단백질을 합성하여 생체재료나 약물전달시스템을 개발하는데 응용하거나, ELFSE의 drag-tag 개발에 응용되는 연구들이 진행되고 있다. 화학적으로 합성된 고분자에 비해 유전공학적으로 합성된 반복단위 고분자의 경우, 고유의 물리적 성질과 함께 환경에 미치는 유해함이 상대적으로 적다는 점 때문에 미래의 신소재로 기대되고 있다.

• Journal of Pharmaceutical Investigation
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• 제31권3호
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• pp.185-190
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• 2001

Human papillomavirus (HPV) infection is known to cause cervical cancers. Human papillomavirus-like particles (VLP) have been studied as preventive vaccines of cervical cancers. To develop VLP as a therapeutic gene carrier, we studied the method to encapsulate cytokine genes in virus-like particles. HPV type 16 capsid L1 genes were amplified by polymerase chain reaction and cloned into T vector. L1 gene was then inserted into baculovirus transfer vector. The clone of baculovirus encoding L1 gene was isolated and used to express L1 protein in Sf 21 insect cells. VLP were purified by CsCl density gradient and ultracentrifugation. VLP were disassembled to capsomer units by treatment of a reducing agent. Given that interleukin-2 (IL-2) genes have been used in anticancer gene therapy and as a molecular adjuvant, IL-2 cytokine plasmids were chosen as a model gene. IL-2 plasmids were incubated with the disassembled capsomer suspension. To reassemble the particles, the mixture of capsomers and cytokine plasmids was dialyzed. The disassembly and reassembly of VLP were confirmed by transmission electron microscopy. The entrapment of cytokine plasmids in reassembled VLP was tested by the stability of plasmids against DNase I. After treatment of reassembled virus-like particles with DNase I, discrete IL-2 DNA band was observed. Our results indicate that IL-2 cytokine plasmid (3.5 kb size) can be encapsulated in the virus-like particles, suggesting the potential of VLP as a gene delivery system. Moreover, VLP containing the adjuvant cytokine plasmids might function as more effective subunit vaccines.

• Journal of Microbiology and Biotechnology
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• 제16권2호
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• pp.318-324
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• 2006

In order to develop an oral vaccine to prevent H. pylori infection, we have expressed the hpaA gene of H. pylori K51 isolated from Korean patients, encoding 29-kDa HpaA that is known to be localized on the cell surface and flagella sheath, in a live delivery vector system, Lactococcus lactis. The hpaA gene, amplified by PCR using the genomic DNA of H. pylori K51, was cloned in the pGEX-2T vector, and the DNA sequence analysis revealed that the hpaA gene of H. pylori K51 had 99.7% and 94.8% identity with individual hpaA genes of the H. pylori 26695 strain (U.K) and the J99 strain (U.S.A). A polyclonal anti-HpaA antibody was raised in rats using GST-HpaA fusion protein as the antigen. The hpaA gene was inserted in an E. coli-L. lactis-shuttle vector (pMG36e) to express in L. lactis. Western blot analysis showed that the expression level of HpaA in the L. lactis transformant remained constant from the exponential phase to the stationary phase, without extracelluar secretion. These results indicate that the HpaA of H. pylori K51 was successfully expressed in L. lactis, and suggest that the recombinant L. lactis expressing HpaA may be applicable as an oral vaccine to induce a protective immune response against H. pylori.

• Molecular & Cellular Toxicology
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• 제5권1호
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• pp.51-57
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• 2009

Quantum Dot (QD) nanoparticles are used in various industrial applications, such as diagnostic, drug delivery, and imaging agents of biomedicine. Although QDs are extensively used in many medical science, several studies have been demonstrated the potential toxicity of nanoparticles. The first objective of this study was to investigate the nanotoxicity of QDs in the HaCaT human keratinocyte cell line by focusing on gene expression pattern. In order to evaluate the effect of QDs on gene expression profile in HaCaT cells, we analyzed the differential genes which related to oxidative stress and antioxidant defense mechanisms by using human cDNA microarray and PCR array. A human cDNA microarray was clone set, which was sorted for a list of genes correlated with cell mechanisms. We tried to confirm results of cDNA microarray by using PCR array, which is pathway-focused gene expression profiling technology using Real-Time PCR. Although we could not find the exactly same genes in both methods, we have screened the effects of QDs on global gene expression profiles in human skin cells. In addition, our results show that QD treatment somehow regulates cellular pathways of oxidative stress and antioxidant defense mechanisms. Therefore, we suggest that this study can enlarge our knowledge of the transcriptional profile and identify new candidate biomarker genes to evaluate the toxicity of nanotoxicology.

• Applied Biological Chemistry
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• 제39권4호
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• pp.260-264
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• 1996

Cymbidium속 난의 형질전환계를 확립하기 위해서, microprojectile bombardment 방법을 이용하여 춘란(Cymbidium virescence)의 rhizome 조직세포에 외래 유전자를 도입하는 조건을 검토하였다. 각 parameter별 적정조건으로서 텅스텐 입자의 크기는 $1.11\;{\mu}m$, He 가스 압력은 $77.33kg/cm^2$, gap distance는 6.35mm, target distance는 7.0cm 이었다. DNA피복입자를 투사한 $400{\mu}m$ 두께의 rhizome 절편을 2개월간 배양한 뒤 GUS 활성을 조사한 결과 이 유전자가 발현되는 세포들이 관찰되었다. Kanamycin (100 mg/L)을 첨가한 배지에서 6개월 동안 선택배양을 통해 얻은 rhizome의 DNA를 PCR로 분석한 결과 nptII 유전자의 삽입을 확인할 수 있었다.

• 한국미생물·생명공학회지
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• 제34권4호
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• pp.329-334
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• 2006

콜레스테롤 유래의 양이온성 리피드 2-aminoethylcarbamate-cholesterol(Chol-E)를 합성하여 이의 리포좀을 제조하였다. 리포좀은 다양한 비율로 중성지방인 DOPE와 섞어서 만든 후 $100{\sim}200nm$의 membrane으로 extrusion시켜 균일한 리포좀을 제작하여 크기 및 전위를 측정하였다. 형광단백질 및 luciferase plasmid의 발현을 여러가지 세포에서 확인한 결과 우수한 발현양상을 보였으며 혈청이 있는 조건에서도 발현이 증가임을 볼수 있었으며, 합성 ODNs의 전달도 adipocyte cell 에서도 잘 이루어지는 것을 확인할 수 있었다 임상실험에 쓰이는 저독성의 DC-chol에 비교하여도 독성이 적은 리포좀임을 알 수 있으며 혈청하에서도 안정하게 유전자를 전달할 수 있는 응용성이 기대되는 새로운 리포좀을 제조하였음을 알 수 있다.

• International Journal of Oral Biology
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• 제39권4호
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• pp.177-185
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• 2014

Transfection is a gene delivery tool that is a popular means of manipulating cellular properties, such as induced pluripotent stem cell (iPSC) generation by reprogramming factors (Yamanaka factors). However, the efficiency of transfection needs to be improved. In the present study, three transfection protocols - non-liposomal transfection (NLT), magnetofection and electroporation - were compared by analysis of their transfection efficiencies and cell viabilities using human dental pulp cells (hDPC) and bovine fetal fibroblasts (bFF) as cell sources. Enhanced green fluorescent protein gene was used as the delivery indicator. For magnetofection, Polymag reagent was administrated. NLT, FuGENE-HD and X-treme GENE 9 DNA transfection reagents were used for NLT. For electroporation, the $Neon^{TM}$ and $NEPA21^{TM}$ electroporators were tested. $Neon^{TM}$ electroporation showed highest transfection efficiency when compared with NLT, magnetofection, and $NEPA21^{TM}$ electroporation, with transfection efficiency of about 33% in hDPC and 50% in bFF, based on viable cell population in each cell type. These results suggest that transfection by $Neon^{TM}$ electroporation can be used to deliver foreign genes efficiently in human and bovine somatic cells.

• 대한의생명과학회지
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• 제27권1호
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• pp.1-11
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• 2021

Cancer stem cells, which are known to drive tumor formation and maintenance, are a major obstacle in the effective treatment of various types of cancer. Trans-membrane glycoprotein mucin 1 antigen and cell surface glycogen CD44 antigen are well-known surface markers of breast cancer cells and breast cancer stem cells, respectively. To effectively treat cancer cells and cancer stem cells, we developed a new drug-encapsulating liposome conjugated with dual-DNA aptamers specific to the surface markers of breast cancer cells and their cancer stem cells. These two aptamer (Apt)-targeted liposomes, which were prepared to encapsulate doxorubicin (Dox), were named "Dual-Apt-Dox". Dual-Apt-Dox is significantly more cytotoxic to both cancer stem cells and cancer cells compared to liposomes lacking the aptamers. Furthermore, we demonstrated the inhibitory efficacy of Dual-Apt-Dox against the experimental lung metastasis of breast cancer stem cells and cancer cells in athymic nude mice. We also showed the potent antitumor effects of dual-aptamer-conjugated liposome systems by targeting cancer cells as well as cancer stem cells. Thus, our data indicate that dual-aptamer-conjugated liposome systems can prove to be effective drug delivery vehicles for breast cancer therapy.

• BMB Reports
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• 제56권9호
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• pp.488-495
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• 2023

Mitochondrial transplantation is a promising therapeutic approach for the treatment of mitochondrial diseases caused by mutations in mitochondrial DNA, as well as several metabolic and neurological disorders. Animal studies have shown that mitochondrial transplantation can improve cellular energy metabolism, restore mitochondrial function, and prevent cell death. However, challenges need to be addressed, such as the delivery of functional mitochondria to the correct cells in the body, and the long-term stability and function of the transplanted mitochondria. Researchers are exploring new methods for mitochondrial transplantation, including the use of nanoparticles or CRISPR gene editing. Mechanisms underlying the integration and function of transplanted mitochondria are complex and not fully understood, but research has revealed some key factors that play a role. While the safety and efficacy of mitochondrial transplantation have been investigated in animal models and human trials, more research is needed to optimize delivery methods and evaluate long-term safety and efficacy. Clinical trials using mitochondrial transplantation have shown mixed results, highlighting the need for further research in this area. In conclusion, although mitochondrial transplantation holds significant potential for the treatment of various diseases, more work is needed to overcome challenges and evaluate its safety and efficacy in human trials.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.