• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.1
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• pp.65-68
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• 2004

The purpose of the present study was to examine the efficacy and mechanism of fraction IV cold ethanol fractionation and pasteurization (60$^{\circ}C$ heat treatment for 10 h), involved in the manufacture of albumin from human plasma, in the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and the amount of virus in each fraction then quantified using a 50% tissue culture infectious dose (TCID$\_$50/). HAV was effectively partitioned from albumin during the fraction IV cold ethanol fractionation with a log reduction factor of 3.43. Pasteurization was also found to be a robust and effective step in inactivating HAV, where the titers were reduced from an initial titer of 7.60 log TCID$\_$50/ to undetectable levels within 5 h of treatment. The log reduction factor achieved during pasteurization was $\geq$4.76. Therefore, the current results indicate that the production process for albumin has sufficient HAV reducing capacity to achieve a high margin of virus safety.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7849-7855
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• 2014

Purpose: To investigate the effect of deacetylase inhibitory trichostatin A (TSA) on anti HepG2 liver carcinoma cells and explore the underlying mechanisms. Materials and Methods: HepG2 cells exposed to different concentrations of TSA for 24, 48, or 72h were examined for cell growth inhibition using CCK8, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under an inverted microscope. Expression of ${\beta}$-catenin, HDAC1, HDAC3, H3K9, CyclinD1 and Bax proteins was tested by Western blotting. Gene expression for ${\beta}$-catenin, HDAC1and HDAC3 was tested by q-PCR. ${\beta}$-catenin and H3K9 proteins were also tested by immunofluorescence. Activity of Renilla luciferase (pTCF/LEF-luc) was assessed using the Luciferase Reporter Assay system reagent. The activity of total HDACs was detected with a HDACs colorimetric kit. Results: Exposure to TSA caused significant dose-and time-dependent inhibition of HepG2 cell proliferation (p<0.05) and resulted in increased cell percentages in G0/G1 and G2/M phases and decrease in the S phase. The apoptotic index in the control group was $6.22{\pm}0.25%$, which increased to $7.17{\pm}0.20%$ and $18.1{\pm}0.42%$ in the treatment group. Exposure to 250 and 500nmol/L TSA also caused cell morphology changes with numerous floating cells. Expression of ${\beta}$-catenin, H3K9and Bax proteins was significantly increased, expression levels of CyclinD1, HDAC1, HDAC3 were decreased. Expression of ${\beta}$-catenin at the genetic level was significantly increased, with no significant difference in HDAC1and HDAC3 genes. In the cytoplasm, expression of ${\beta}$-catenin fluorescence protein was not obvious changed and in the nucleus, small amounts of green fluorescence were observed. H3K9 fluorescence protein were increased. Expression levels of the transcription factor TCF werealso increased in HepG2 cells following induction by TSA, whikle the activity of total HDACs was decreased. Conclusions: TSA inhibits HDAC activity, promotes histone acetylation, and activates Wnt/${\beta}$-catenin signaling to inhibit proliferation of HepG2 cell, arrest cell cycling and induce apoptosis.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.303-310
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• 2002

Cell therapy applied to wound healing or tissue regeneration presents a revolutionary realm to which principles of gene engineering and delivery may be applied. One promising application is the transplantation of cells into the wounded tissue to help the tissue repair. However, when cells are transplanted from in vitro to in vivo, immune rejection occurs due to the immune response triggered by the activation of T-cell, and the transplanted cells are destroyed by the attack of activated T-cell and lose their function. Immune suppressant such as FK506 is commonly used to suppress immune rejection during transplantation. However, such kind of immune suppressants not only suppresses immune rejection in the periphery of transplanted cells but also suppresses whole immune response system against pathogenic infection. In order to solve this problem, we developed a method to protect the desired cells from immune rejection without impairing whole immune system during cell transplantation. Previously, we reported the success of constructing glomerular epithelial cells for removal of immune complex, in which complement receptor of type 1 (CR1) was over-expressed on the membrane of renal glomerular epithelial cells and could bind immune complex of DNA/anti-DNA-antibody to remove immune complex through phagocy-tosis [1]. Attempting to apply the CR1-expressing cells to cell therapy and evade immune rejection during cell transplantation, we constructed three plasmids containing genes encoding a soluble fusion protein of cytolytic T lymphocyte associated antigen-4 (CTLA4Ig) and an enhanced green fluorescent protein (EGFP). The plasmids were transfected to the above-mentioned glomerular epithelial cells to express both genes simultaneously. Using the clone cells for cell transplantation showed that mice with autoimmune disease prolonged their life significantly as compared with the control mice, and two injections of the cells at the beginning of two weeks resulted in remarkable survivability, whereas it requires half a year and 50 administrations of proteins purified from the same amount of cells to achieve the same effect.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.276-283
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• 2009

Enrichment in nutrients coming from urban sewage outfalls can lead to eutrophication in coastal areas, which can also change the species composition and community structure of macro algal communities. We investigated the structure of the macro algal community within three rocky shores in order to assess any possible differences in their characteristics. Site 1 was located near Tongyeong city's sewage outfall, Site 2 was located near a public beach area, and Site 3 faced open channel of the Ocean. All three sites were located within the same stretch of the coast, where Site 2 was located between sites 1 and 3. We measured the nutrient concentration in water and the tissue nitrogen content in macro algae samples. Nutrients in the water column surrounding site 1 were high in ammonium ($30.2\pm1.8{\mu}M$), nitrate ($26.2{\pm}0.1{\mu}M$), and phosphate ($2.7{\pm}0.1{\mu}M$) content, and were characterized by low numbers of macroalgal species and species and a low species diversity index. In contrast, site 3 exhibited relatively low nutrient concentration levels and a high number of macroalgal species and a high species diversity index. Comparative analysis showed that the tissue nitrogen content of macroalgae were significantly (P<0.05) affected by the nutrient concentration in the water column. The tissue nitrogen content of green algae within site 1 was higher than the others sites. However, the tissue nitrogen content of brown algae was similar at all three sites. Thus, the tissue nitrogen content of macro algae and the macro algal community structure of intertidal rocky shores were dependent on location and the performance of macroalgal communities was dependent on water quality.

• Carbon letters
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• v.15 no.1
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• pp.1-14
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• 2014

Carbon nanofibers (CNFs) with diameters in the submicron and nanometer range exhibit high specific surface area, hierarchically porous structure, flexibility, and super strength which allow them to be used in the electrode materials of energy storage devices, and as hybrid-type filler in carbon fiber reinforced plastics and bone tissue scaffold. Unlike catalytic synthesis and other methods, electrospinning of various polymeric precursors followed by stabilization and carbonization has become a straightforward and convenient way to fabricate continuous CNFs. This paper is a comprehensive and brief review on the latest advances made in the development of electrospun CNFs with major focus on the promising applications accomplished by appropriately regulating the microstructural, mechanical, and electrical properties of as-spun CNFs. Additionally, the article describes the various strategies to make a variety of carbon CNFs for energy conversion and storage, catalysis, sensor, adsorption/separation, and biomedical applications. It is envisioned that electrospun CNFs will be the key materials of green science and technology through close collaborations with carbon fibers and carbon nanotubes.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.70-76
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• 2022

Calcium-phosphate-based bioceramics are promising biomaterials for scaffolds because they can assist in bone regeneration. In this study, a laser sintering deposition system was developed, and 3D hydroxyapatite (HA) scaffolds were fabricated. The main process conditions of the HA scaffolds were laser power, table velocity, and laser focal distance. As the laser power increased, the line width, line height, and layer thickness also increased. Further, the line width, line height, and layer thickness decreased as the table velocity increased. As the laser focal distance increased, the line width increased, but the line height and layer thickness decreased. The fabricated green scaffolds were sintered at 1050 ℃ and 1150 ℃. The sintered scaffolds had a uniform and continuous interconnected shape, with pore sizes ranging from 850 to 950 ㎛ having 53% porosity. The compressive strength of the scaffolds decreased from 0.72 MPa (1050 ℃) to 0.53 MPa (1150 ℃). The biocompatibility of the scaffolds was investigated by analyzing the adhesion of osteoblast-like MG-63 cells cultured on the surfaces of the scaffolds. The results indicate that the scaffold sintered at 1050 ℃ had good mechanical and biological properties compared to that at 1150 ℃.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.758-763
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• 1997

Fresh jujubes (Zizyphus jujuba Miller) of whitish green and red ripe maturities were stored at 5 different temperatures, and quality changes through the storage were measured to find an optimal storage condition. Respiration rates and their temperature dependences for both maturities were not different from each other, which suggested non-climacteric pattern of postharvest respiration. Red ripe fruits showed heavier weight and higher content in soluble solid and ascrobic acid compared with whitish green mature fruits. Through the storage of jujubes in perforated packages tissue softening and decay were main visual quality deteriorations with the former preceding the latter. The whitish green mature jujubes showed slower rate of quality changes in softening and decay than red ripe ones, and are thus more suitable for long term storage. In the storage, the whitish green fruits changed into red color, and showed increase in soluble solid and decrease in acidity and ascorbic acid content. Storing the jujubes at $-2^{\circ}C$ resulted in symptoms of chilling injury, and storing at higher temperatures above $0^{\circ}C$ accelerated the decay and softening. $0^{\circ}C$ was found to be optimal temperature for long term storage, where jujube had the lowest rate of quality changes without chilling injury. Even at optimal temperature of $0^{\circ}C$, however, storage life retaining freshness was only around 40 days which is not enough.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.14-21
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• 2008

Bovine blood, cell, tissue, and organ are used as raw materials for manufacturing biopharmaceuticals, tissue engineered products, and cell therapy. Manufacturing processes for the biologicals using bovine materials have the risk of viral contamination. Therefore viral validation is, essential in ensuring the safety of the products. Bovine herpesvirus type 1 (BHV-1) is the most common bovine pathogen found in bovine blood, cell, tissue, and organ. In order to establish the validation system for the BHV-1 safety of the products, a real-time PCR method was developed for quantitative detection of BHV-1 in raw materials, manufacturing processes, and final products as well as BHV-1 clearance validation. Specific primers for amplification of BHV-1 DNA was selected, and BHV-1 DNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be $2\;TCID_{50}/ml$. The real-time PCR method was validated to be reproducible and very specific to BHV-1. The established real-time PCR assay was successfully applied to the validation of Chinese hamster ovary (CHO) cell artificially infected with BHV-1. BHV-1 DNA could be quantified in CHO cell as well as culture supernatant. Also the real-time PCR assay could detect $10\;TCID_{50}/ml$ of BHV-1 artificially contaminated in bovine collagen. The overall results indicated that this rapid, specific, sensitive, and robust assay can be reliably used for quantitative detection of BHV-1 contamination during the manufacture of biologics.

• International Neurourology Journal
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• v.22 no.4
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• pp.260-267
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• 2018

Purpose: A major question remaining in approaches to tissue engineering and organ replacement is the role of native mobilized native cells in the regeneration process of damaged tissues and organs. The goal of this study was to compare the cell mobilizing effects of the chemokine CXCL12 and cell therapy on the urinary sphincter of nonhuman primates (NHP) with chronic intrinsic urinary sphincter dysfunction. Methods: Either autologous lenti-M-cherry labeled skeletal muscle precursor cells (skMPCs) or CXCL12 were injected directly into the sphincter complex of female NHPs with or without surgery-induced chronic urinary sphincter dysfunction (n=4/treatment condition). All monkeys had partial bone marrow transplantation with autologous lenti-green fluorescent protein (GFP) bone marrow cells prior to treatment. Labeled cells were identified, characterized and quantified using computer-assisted immunohistochemistry 6 months posttreatment. Results: GFP-labeled bone marrow cells (BMCs) were identified in the bone marrow and both BMCs and skMPCs were found in the urinary sphincter at 6-month postinjection. BMCs and skMPCs were present in the striated muscle, smooth muscle, and lamina propria/urothelium of the sphincter tissue. Sphincter injury increased the sphincter content of BMCs when analyzed 6-month postinjection. CXCL12 treatment, but not skMPCs, increased the number of BMCs in all layers of the sphincter complex (P<0.05). CXCL12 only modestly (P=0.15) increased the number of skMPCs in the sphincter complex. Conclusions: This dual labeling methodology now provides us with the tools to measure the relative number of locally injected cells versus bone marrow transplanted cells. The results of this study suggest that CXCL12 promotes mobilization of cells to the sphincter, which may contribute more to sphincter regeneration than injected cells.

• Journal of Biomedical Engineering Research
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• v.37 no.5
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• pp.186-194
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• 2016

In this study, a co-axial flow induced microfluidic chip to fabricate pure collagen type I microfiber via the control of collagen type I and Na-alginate gelation process. The pure collagen type I microfiber was generated by selective degradation of Ca-alginate from 'Core-Shell' structured hydrogel microfiber. To make 'Core-Shell' structure, collagen type I solution was introduced into core channel and 1.5% Na-alginate solution was injected into side channel in microfluidic chip. To evaluatethe 'Core-Shell' structure, the red and green fluorescence substances were mixed into collagen type I and Na-alginate solution, respectively. The fluorescence substances were uniformly loaded into each fiber, and the different fluorescence images were dependent on their location. By immoblizing EpH4-Ras and C6 cells within collagen type I and Na-alginate solution, we sucessfully demonstrated the co-culture of EpH4-Ras and C6 cells with 'Core-Shell' like hydrogel microfiber for 5 days. Only to produce pure collagen type I hydrogel fiber, tri-sodium citrate solution was used to dissolve the shell-like Ca-alginate hydrogel fiber from 'Core-Shell' structured hydrogel microfiber, which is an excellent advantage when the fiber is employed in three-dimensional scaffold. This novel method could apply various application in tissue engineering and biomedical engineering.