• KSBB Journal
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• 제8권5호
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• pp.478-482
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• 1993

LSM을 이용하여 KA112 균주의 고농도 배양을 시도하였다. Separator로는 hollow fiber를 사용하였고 reactor로는 Celligen을 이용하였다. Wroking volume 1리터로 10일간 배양하여 최고 세포농도가 회분식 배양에 비하여 10배 이상 증가한 $2.1\times10^7$ cells/ml이었고, 항체의 농도는 4.5배 정도 높았다. 최고 feed rate에서 항체생산속도는 회분식 배양보 다 9배 높았으며 배양 중 glucose농도가 Ig/e 이상일 때 specific productivity가 증가하였고, 1 g/6 이하얼 때 세포성장은 영향을 받지 않으냐 spe­c cific prodictivity는 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제4권3호
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• pp.200-203
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• 1994

Spodoptera frugiperda IPLB-SF-21-AE cells were cultivated in a spin-filter bioreactor with continuous perfusion for the recombinant $\beta$-galactosidase production. At the perfusion rate of 0.06 $hr^{-1}$, the maximum cell density of insect cells in this bioreactor system reached 3.5$\times$$l0^6$ viable cells/ml using the Grace media containing 5% FBS and 0.3% Pluronic F-68. The recombinant $\beta$-galactosidase production of 8, 100 units per reactor volume was also achieved at this perfusion rate.

• KSBB Journal
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• 제14권2호
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• pp.188-191
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• 1999

본 실험에서는 하이브리도마세포 배양 중 아미노산 량의 변화를 조사하여 세포성장, 세포대사 및 항체생산성에 미치는 아미노산의 영향을 조사하였다. 실험결과에 의하면 vR8 하이브리도 마세포 배양 중 세포성장이 급속히 이루어지는 시점과 최대 세포농도에 도달한 시점에서의 glutamine, arginine, leucine 등 다수 아미노산의 고갈이 관찰되었고, 이후 세포활성이 급속히 저하되었다. 이때 glucose 농도, lactate, armmonia 등의 대사산물 농도 및 pH, DO, 교반속도 등은 적절하게 유지되었기 때문에 이들 요소에 의한 세포성장의 저해는 없었다. 따라서 이들 아미노산의 고갈이 세포활성의 저하에 커다란 영향을 주었다고 생각된다. 한편, 고갈된 아미노산을 첨가한 배지(GC-HY-S2)로 배양을 해본 결과 세포농도를 $2.91\times10^7$cell/mL까지 증가시킬 수 있었다. 즉, 변형배지에서는 세포활성의 저하를 가져오는 세포성장구간을 지나 계속적인 세포성장을 보여 27배 정도 더 높은 최대 세포농도를 보였다. 세포농도의 증가로 specific productivity, volumetric productivity도 각각 1.75배, 56배 증가하였다. 최대 세포농도에서의 아미노산 량을 조사한 결과를 보면 충분한 양의 아미노산이 공급되었음을 알 수 있다. 고농도 하이브리도마세포 배양에서의 일부 아미노산의 고갈은 일반적으로 관찰되는 현상이다. 그러므로 세포를 고농도로 배양하기 위해서는 아미노산 분석을 통해 고갈된 아미노산을 첨가해 주어야 하는데, 아미노산의 요구는 세포주마다 다르므로 배지 최적화과정에서 아미노산 분석에 의한 배지의 개선이 필요하다고 생각된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.51-54
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• 1998

It has been proved that co-cultivation of human neroblastoma cells and human fibroblast cells can enhance nerve cell growth and the production of BDNF in perfusion cultivation. In batch co-cultivation, maximum cell density was increased up to 1.76${\times}$106 viable cells/mL from 9${\times}$105 viable cells/mL of only neuroblastoma cell culture. The growth of neuroblastoma cells was greatly improved by culturing both nerve and fibroblast cells in a perfusion process, maintaining 1.5${\times}$106 viable cells/mL, which was much higher than that form fed-batch cultivation. The nerve cell growth was greatly enhance in both fed-batch and perfusion cultivations while the growth of fibroblast cells was not. It strongly implies that the factors secreted from human fibrobast cells and/or the environments of co-culture system can enhance both cell growth and BDNF secretion. Specific BDNF production rate was not enhanced in co-cultures; however, the production period was increased as the cell growth was lengthened in the co-culture case. Competitive growth between nerve cells and fibroblast cells was not observed in all cases, showing no changes of fibroblast cell growth and only enhancement of the neuroblastoma cell growth and overall BDNF production. It was also found that the perfusion cultivation was the most appropriate process for cultivating two cell lines simultaneously in a bioreactor.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.406-410
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• 2002

A new spin filter consisting of $50{\mu}m$ (nominal pore size) depth fitters rolled on a stainless steel grid was developed, using Saccharomyces cerevisiae as a model suspension cell to evaluate the spin filter performance. In a 1.8-1 fermentor with a rotation speed of 300 rpm and perfusion rate of 4 ml/min, a cell concentration of 49 g/l and ethanol concentration of 45 g/l from 100 g/l glucose could be obtained in a perfusion culture. The major mechanisms for cell separation used by the large-pore spin filter appeared to be centrifugal force and pivotal movement of the cells in the spin filter.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권1호
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• pp.41-46
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• 2003

Difficulties associated with bioartificial liver (BAL) preservation limit not only the commercialization of BAL, but also its clinical trials. In this study, the possibility of cold preservation of BAL cartridges containing porcine hepatocytes was examined at 4$^{\circ}C$. In an in vitro perfusion culture System, BAL cartridges maintained cytochrome P450 metabolic function for at least 50 days. However, all BAL cartridges completely lost their ammonia eliminating ability when stored at 4$^{\circ}C$. We a1so studied the effect of cell density on the maintenance of BAL liver function In a highly differentiated and healthy state. As expected, BALs containing a larger number of hepatocytes demonstrated higher metabolic functions. When metabolic functions were compared per gram of hepatotytes, no large differences were observed between devices containing different densities of hepatocytes. Decreased cell density did not Successfully prolong BAL function. The viability and function of isolated hepatotytes highly depend on the culture conditions, such as cell density, substrata, culture media, and additives to the culture media. Perfusion culture of BAL cartridges at 4$^{\circ}C$ gave a promosing result with respect to the maintenance of P450 activity. However, as indicated by the rapid loss of ammonia metabolic activity, many factors still remain to be optimized for preservation of BAL keeping high metabolic functions for a longer time.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.421-421
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• 2005

• KSBB Journal
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• 제7권4호
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• pp.271-277
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• 1992

쥐 간세포를collagenase perfusion method에 의해 분리한 뒤 collagen coated dish와floating collagen membrane에서 일차배양하여 간세포의 분화기능을 조사하였다. 두 경우 모두 간세포의 생존율은 5일 이후부터 점차 감소하였거나 간세포에 의한 암모니아 처리기능과 albumin생성기능은 약 7일간 유지되었다. 또 이러한 분화기능에 유지는 ollagen coated dish보다floating collagen membrane이 유리한 것으로 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.73-76
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• 1997

Biopolymer membrane was prepared using two oppositely charged natural biopolymer. The biopolymer membrane was used for the encapsulation of two hybridoma cell lines(ATCC CRL-1606, ATCC BH-8852) to produce monoclonal antibodies. In order to reduce the down stream steps, the pore size of the membrane was controlled to retain the monoclonal antibodies in the capsules based on the diffusion experiments with standard proteins. T-flask culture showed cell densities of 8$\times$107cells/mL 3$\times$107cells/mL, and MAb concentrations of 506 $\mu\textrm{g}$/mL and 109$\mu\textrm{g}$/mL for encapsulated ATCC CRL-1606 and HB-8852, respectively. Two liter perfusion culture with encapsulated ATCC HB-8852 was performed to enhance the MAb production. The MAb production of the encapsulated hybridoma increased considerably comparing to the culture using silicone tubing for oxygen transfer.

• Toxicological Research
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• 제5권1호
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• pp.9-15
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• 1989

The effect of butylated hydroxytoluene (BHT) and its major metabolite, 3, 5-di-tert-butyl-4-hydroxybenzoic acid (BHT-acid) on the uptake of taurocholate into hepatocytes was studied using the primary culture of rat hepatocytes. Hepatocyte were isolated by an in situ collagenase perfusion technique and maintained as a monolayer in serum-free meadia for 24 hours before use. The uptake of taurocholate was saturable with an apparent Km of 12.8+2.8 MuM and Vmax of 0.18+0.01 nmol/mg/min. Both BHT and BHT-acid inhibited the hepatocellular uptake of taurocholate when they were added to the culture.