• The Korean Journal of Physiology and Pharmacology
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• 제24권6호
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• pp.441-452
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• 2020

In vivo animal models are limited in their ability to mimic the extremely complex systems of the human body, and there is increasing disquiet about the ethics of animal research. Many authorities in different geographical areas are considering implementing a ban on animal testing, including testing for cosmetics and pharmaceuticals. Therefore, there is a need for research into systems that can replicate the responses of laboratory animals and simulate environments similar to the human body in a laboratory. An in vitro two-dimensional cell culture model is widely used, because such a system is relatively inexpensive, easy to implement, and can gather considerable amounts of reference data. However, these models lack a real physiological extracellular environment. Recent advances in stem cell biology, tissue engineering, and microfabrication techniques have facilitated the development of various 3D cell culture models. These include multicellular spheroids, organoids, and organs-on-chips, each of which has its own advantages and limitations. Organoids are organ-specific cell clusters created by aggregating cells derived from pluripotent, adult, and cancer stem cells. Patient-derived organoids can be used as models of human disease in a culture dish. Biomimetic organ chips are models that replicate the physiological and mechanical functions of human organs. Many organoids and organ-on-a-chips have been developed for drug screening and testing, so competition for patents between countries is also intensifying. We analyzed the scientific and technological trends underlying these cutting-edge models, which are developed for use as non-animal models for testing safety and efficacy at the nonclinical stages of drug development.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권3호
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• pp.207-210
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• 2000

When endothelial cells isolated isolated from human umbilical venis were cultred for 6dary using 96-well microplates, the final cell density in each was fiund not to be the same although the medium composition of each well was exactly the same. Cell growth in the wells located at the periphery of a microplate was low, while that in the central area of the plate was high. A possible cause for different rate of growth was proposed as the uneven concentration of oxygen in the culture medium of each well.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2004년도 제47차 추계학술대회
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• pp.67-68
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• 2004

• 한국식품영양학회지
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• 제22권2호
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• pp.313-319
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• 2009

To improve the growth of human mesenchymal stem cells(hMSCs) under general cell culture conditions(20% $O_2$ and 5% $CO_2$), we examined the effect of s-allylcysteine(SAC), which is known as an antioxidant and the main component of aged-garlic extract, on hydrogen peroxide-induced cellular stress in hMSCs. We found that SAC blocked hydrogen peroxideinduced cell death and cellular apoptosis, but that SAC did not improve the growth of hMSCs during short-term culture. To evaluate the protective effect of SAC, we examined the endogenous expression of the antioxidant enzymes catalase (CAT), superoxide dismutase(SOD), and glutathione peroxidase(Gpx) in hMSCs. Hydrogen peroxide was found to downregulate the expression of CAT, SOD, and Gpx at the protein level. However, in the pre-treatment group of SAC, SAC inhibited the hydrogen peroxide-induced down-regulation of CAT, SOD, and Gpx. Unfortunately, treatment with SAC alone did not induce the up-regulation of antioxidant enzymes and the cell proliferation of hMSCs. Surprisingly, SAC improved cell growth in a single cell level culture of hMSCs. These results indicate that SAC may be involved in the preservation of the self-renewal capacity of hMSCs. Taken together, SAC improves the proliferation of hMSCs via inhibition of oxidative-stress-induced cell apoptosis through regulation of antioxidant enzymes. In conclusion, SAC may be an indispensable component in an in vitro culture system of human MSCs for maintaining self-renewal and multipotent characterization of human MSCs.

• Molecules and Cells
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• 제19권1호
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• pp.46-53
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• 2005

Human embryonic stem (hES) cells, unlike most cells derived from adult or fetal human tissues, represent a potentially unlimited source of various cell types for basic clinical research. To meet the increased demand for characterized hES cell lines, we established and characterized nine new lines obtained from frozen-thawed pronucleus-stage embryos. In addition, we improved the derivation efficiency from inner cell masses (to 47.4%) and optimized culture conditions for undifferentiated hES cells. After these cell lines had been maintained for over a year in vitro, they were characterized comprehensively for expression of markers of undifferentiated hES cells, karyotype, and in vitro/in vivo differentiation capacity. All of the cell lines were pluripotent, and one cell line was trisomic for chromosome 3. Improved culture techniques for hES cells should make them a good source for diverse applications in regenerative medicine, but further investigation is needed of their basic biology.

• Reproductive and Developmental Biology
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• 제31권4호
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• pp.267-272
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• 2007

Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and have the capacity to differentiate into various types of cells in the body. Hence, these cells may potentially be an indefinite source of cells for cell therapy in various degenerative diseases including neuronal disorders. For clinical applications of human ES cells, directed differentiation of these cells would be necessary. The objective of this study is to develop the culture condition for the expansion of neural precursor cells derived from human ES cells. Human ES cells were able to differentiate into neural precursor cells upon a stepwise culture condition. Neural precursor cells were propagated up to 5000-fold in cell numbers over 12-week period of culture and evaluated for their characteristics. Expressions of sox1 and pax6 transcripts were dramatically up-regulated along the differentiation stages by RT-PCR analysis. In contrast, expressions of oct4 and nanog transcripts were completely disappeared in neural precursor cells. Expressions of nestin, pax6 and sox1 were also confirmed in neural precursor cells by immunocytochemical analysis. Upon differentiation, the expanded neural precursor cells differentiated into neurons, astrocytes, and oligodendrocytes. In immunocytochemical analysis, expressions of type III ${\beta}$-tubulin and MAP2ab were observed Presence of astrocytes and oligodendrocytes were also confirmed by expressions of GFAP and O4, respectively. Results of this study demonstrate the feasibility of long-term expansion of human ES cell-derived neural precursor cells in vitro, which can be a potential source of the cells for the treatment of neurodegenerative disorders.

• KSBB Journal
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• 제11권2호
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• pp.254-261
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• 1996

수두 바이 러스(Varicella-zoster virus, VZV) 백신을 생산하기 위하여 약독화된 수두 바이러스 주인 Oka 주를 사용하여 정상세포인 인체 폐세 포(human lung fibroblast cells)로부터 수두 바이 러스 생산조건을 검토하였다. 숙주세포의 배양을 위 한 최적 성장배지로는 DMEM이 조사된 배지 중에 서는 가장 좋음을 알 수 있었으며 숙주세포의 성장율은 세포 age의 지표인 population doubling level (PDL) 이 46 이상인 경우 낮아지는 것무로 확인되 었으며 따라서 수두바이러스 생산을 위해서는 PDL 4 46 이하의 young cell을 사용해야 할 것으로 사료된 다 한편 수두바이러스 생산을 위한 최적 증식조건 으로는 배양온도 $37^{\circ}C$, 혈청농도 2%, MOl 1:5였다. 숙주세포를 대량배양하기 위한 기본조건을 검토 하기 위하여 미 럽담체 (Cytodex-3)를 이용한 spm­n ner flask culture를 시행하였다. 미럽담체에서의 숙 주세포 성장은 T -flask와 비하여 별다른 차이가 없었으나 VZV의 증식은 T-flask 배양에서보다 훨씬 낮았다. 이는 미립담체배양에서의 높은 전단응력 과 미립담체끼리의 영김현상 때문으로 생각된다.

• Journal of Pharmaceutical Investigation
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• 제32권1호
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• pp.21-26
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• 2002

The primary culture of human nasal epithelial cell monolayer was performed on a Transwell. The effect of various factors on the tight junction formation was observed in order to develop an in vitro experimental system for nasal transport studies. Human nasal epithelial cells, collected from human normal inferior turbinates, were plated onto diverse inserts. After 4 days, media of the apical surface was removed for air-liquid interface (ALI) culture. Morphological characteristics was observed by transmission electron microscopy (TEM). A polyester membrane of $0.4\;{\mu}m$ pore size was determined as the most effective insert based on the change in the transepithelial electric resistance (TEER) value as well as the $^{14}C-mannitol$ transport study. The ALI method was effective in developing the tight junction as observed in the further increase in the TEER value and reduction in the permeability coefficient $(P_{app})$ of $^{14}C-mannitol$ transport. Results of the transport study of a model drug, budesonide, showed that the primary culture system developed in this study could be further developed and applied for in vitro nasal transport studies.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권2호
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• pp.106-109
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• 2000

Vascular endothelial cells (EGs) are usually difficult to culture to culture in a large scale because of their complicated requirements for cell growth. As the vascular endothelial growth factor (VEGF) is a key growth factor in the EC culture, we transfected human umbilical vein endothelial cells (HUVEC) using a plasmid containing VEGF gene and let them grow in a culture medium eliminated an important supplement, endothelail cell growth supplement(ECGS). The expression of VEGF by HUVEC tansfected with Vegf GENE was not enough to stimulate the growth of HUVEC, only 40% of maximum cell density obtainable in the presence of ECGS. However, when the culture medium was supplied with 2.5 ng/ml of basic fibroblast growth factor (bFGF), a synergistic effect effect of VEGE and bFGF was observed. In this case, the final cell density was recovered was recovered up to about 78% of maxium value.

• 한국동물생명공학회지
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• 제37권1호
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• pp.62-66
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• 2022

To date, the development of anticancer drugs has been conducted using two-dimensional (2D) cell culture systems. However, since cancer cells in the body are generated and developed in three-dimensional (3D) microenvironments, the use of 2D anticancer drug screening can make it difficult to accurately evaluate the anticancer effects of drug candidates. Therefore, as a step towards developing a cancer cell-friendly 3D microenvironment based on a combination of vinylsulfone-functionalized polyethylene glycol (PEG-VS) with dicysteine-containing crosslinker peptides with an intervening matrix metalloproteinase (MMP)-specific cleavage site, the types of MMPs secreted from human hepatocarcinoma HepG2 cells, a representative cancer cell, were analyzed transcriptionally and translationally. MMP3 was confirmed to be the most highly expressed protease secreted by HepG2 cells. This knowledge will be important in the design of a crosslinker necessary for the construction of PEG-based hydrogels customized for the 3D culture of HepG2 cells.