• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.61-70
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• 2022

Natural and synthetic forms of calcium phosphate cement (CPC) have been widely used in bone repair and augmentation. The major challenge of injectable CPC is to deliver the cells without cell death in order to regenerate new bone. The study objective was to investigate for the potential of stem cell-laden gelatin fibers containing injectable, nanocrystalline CPC to function as a delivery system. Gelatin noddle fiber method was developed to delivered cells into nCPC. Experimental groups were prepared by mixing cells with nCPC, mixing cell-laden gelatin fibers with nCPC and mixing cell-laden gelatin fibers containing BMP-2 with nCPC. Media diffusion test was conducted after dissolving the gelatin fibers. SEM examined the generated channels and delivered cell morphology. Fibers mixed with nCPC showed physical setting and hardening within 20 min after injection and showed good shape maintenances. The gelatin fibers mixed nCPC group had several vacant channels generated from the dissolved gelatin. Particularly, proliferation and attachment of the cells were observed inside of the channels. While live cells were not observed in the cell mixed nCPC group, cells delivered with the gelatin fibers into the nCPC showed good viability and increased DNA content with culture. Cell-laden gelatin fiber was a novel method for cell delivery into nCPC without cell damages. Results also indicated the osteogenic differentiation of gelatin fiber delivered cells. We suggest that the cell-laden gelatin fibers mixed with nCPC can be used as an injectable cell delivery vehicle and the addition of BMP-2 to enhances osteogenesis.

• The Korean Journal of Zoology
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• v.28 no.3
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• pp.151-165
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• 1985

The morphological changes of the midgut epithelium during the metamorphosis of pine caterpillar are observed with light and electron microscope, being divided into 5 stages from the 8th instar larva to just after pupation. The midgut epithelium of 8th instar larva is composed of columnar cell, goblet cell, regenerative cell, and endocrine cell. The secretorials are arranged on the nuclear membrane in the columnar cell of the midgut epithelium in the 8th instar larva, and lysosomes are augmented in the apical portion. Cytoplasmic extrusions are observed in the apical surface of columnar cell but they have no cell organells. Nucleus, mitochondria, rER, Golgi complex, and free ribsomes are observed in the regenerative cell. Regenerative cells are differentiated into the form of goblet cell, and vacuoles are gradually increased in the cytoplasm. Just pupa stage, the materials, which appears to be mainly composed of Ca, are observed in the circular form and goblet cavity of regenerative cell are detached to lumen. As a result, it reflects the process of the degeneration of the midgut epithelium that lysosomes are gradually augmented in the columnar cell, that nuclear materials are removed to cytoplasm, and that cytoplasmic extrusions are observed in the apical surface. And though regenerative cells are differentiated into the form of the goblet cell, it is believed that goblet cavity is detached from regenerative cell to the lumen and midgut epithelium of pupa stage is formed.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.333-337
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• 2000

An oil-degrading yeast, Yarrowia lipolytica 180, exhibits interesting cell surface characteristics under the growth on hydrocarbons. An electron microscopic study revealed that the cells grown on crude oil showed protrusions on the cell surface, and thicker periplasmic space and cell wall than the cell surface, and thicker periplasmic space and cell wall than the cells grown on glucose. Y. lipolytica cells lost its cell hydrophobicity after pronase(0.1 mg/ml) treatment. The strain produced two types of emulsifying materials during the growth on hydrocarbons; one was water-soluble extracellular materials and the other was cell wall-associated materials. Both emulsifying materials at lower concentration (0.12%) enhanced the oil-degrading activity of Moraxella sp. K12-7, which had medium emulsifying activity and negative cell hydrophobicity; however, it inhibited the oil-degrading activity of Pseudomunas sp. K12-5, which had medium emulsifying activity and cell hydrophobicity. These results suggest that the oil-degrading activity of Y. lipolytica 180 is closely associated with cell surface structure, and that a finely controlled application of Y.lipolytica 180 in combination with other oil-degrading microorganisms showed a possible enhancing efficiency of oil degradation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.10
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• pp.844-849
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• 2008

We present a novel cell deformability monitoring chip based on the digitally measured cell lysis rate which is dependent on the areal strain of the cell membrane. This method offers simple cell deformability monitoring by automated high-throughput testing system. We suggest the filter design considering the areal strain imposed on the cell membrane passing through the filter array having gradually increased orifice length. In the experiment using erythrocytes, we characterized the cell deformability in terms of average fracture areal strain which was $0.24{\pm}0.014\;and\;0.21{\pm}0.002$ for normal and chemically treated erythrocytes, respectively. We also verified that the areal strain of 0.15 effectively discriminates the deformability difference of normal and chemically treated erythrocytes, which can be applied to the clinical situation. We compared the lysis rates and their difference for the samples from different donors and found that the present chips can be commonly used without any calibration process. The experimental results demonstrate the simple structure and high performance of the present cell deformability monitoring chips, applicable to simple and cost-effective cell aging process monitoring.

• KSBB Journal
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• v.9 no.2
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• pp.230-237
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• 1994

Spin-filters are used as cell separation devices for achieving high cell density and high productivity in animal cell culture. We have proposed a model for the cell growth in a spin-filter perfusion culture and examined the effects on cell growth by several parameters including ammonia inhibition, specific growth rate, specific feeding rate, and cell retention. Results from computer simulation and sensitivity analysis indicate that the cell retention affects the cell growth mostly while there is a significant inhibition on cell growth by the ammonia accumulated during the culture. The specific feeding rate has minimal effects on cell growth, which is consistant with the fact that the cell growth with a step feeding is quite similar to that with a continuous feeding.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.5
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• pp.493-498
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• 2015

The fuel cell vehicle is a type of hydrogen vehicle which uses a fuel cell to produce electricity, powering its on-board electric motor. The fuel cell vehicle driving principle is completely different from the internal combustion engine vehicle. In order to ensure the durable quality of the fuel cell vehicle, durability test mode considering the characteristics of the fuel cell must be developed. In this study, we derived the durability test mode profile through collecting and analyzing fuel cell vehicle driving data. Then, the accelerated durability test mode is developed by adding degradation conditions and is experimentally validated to have an acceleration factor of 5~6.

• Environmental Analysis Health and Toxicology
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• v.4 no.3_4
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• pp.29-59
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• 1989

For the purpose of electrolytic treatment of wastewater containing various heavy metals, the BPBE Cell of batch and continuous type was considered and experimented. Some results from this study were summarized as follows: 1. When the artificial wastewater containing 500 mg/l of the concentration of various heavy metallic ion was electrolyzed in BPBE Cell of batch type, the removal efficicency was over 95% in cadmiun (II), lead (II), chromium (Ⅵ) and over 85% in copper (II), chromium (III). 2, As granular activated carbon packed in BPBE Cell, coconut shell was superior to lignite and the removal efficiency was the highest when the activated carbon was 4/6 mesh, the voltage was 20V. 3. When the heavy metallic ion in wastewater was electrolyzed in BPBE Cell of continuous type, about 1,000mg of heavy metal per 1kg of coconut sell could be removed. 4. The treatment method of heavy metallic ion in wastewater by BPBE Cell cost less than in the former chemical treatment method and the coconut shell packed in BPBE Cell could be regenerated by chemical method.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.673-676
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• 2016

Background: In the maxillofacial region, giant cell granulomas occur in 2 clinical forms, central and peripheral. Despite histopathological similarity between these 2 forms totally different clinical behaviors have been reported. The present study was undertaken to compare mast cell and vascular concentrations in these pathologic lesions. Materials and Methods: In this cross-sectional descriptive study, 20 pathological samples of central giant cell granuloma (CGCG) and 20 samples of peripheral giant cell granuloma (PGCG) were selected and examined through toluidine blue staining for mast cell assessment and immunohistochemical staining by VEGEF antibody for comparing the number of mast cells. T-test, chi-squared test and backward multivariate linear regression were used for statistical analysis using SPSS 20. Statistical significance was set at P<0.05. Results: This study showed significantly greater VEGF expression and mast cell concentrations in CGCG compared to PGCG cases. Also there was a significant correlation between VEGF expression and the concentration of mast cells. No relation was found between age, sex and site of the lesion and concentration of mast cells or VEGF expression. Conclusions: It is feasible that higher concentrations of mast cells in CGCG versus PGCG samples might lead to more aggressive clinical behavior via vascular proliferation and angiogenesis. However, other biologic mechanisms should be considered in this situation.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.18-23
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• 2002

Ailanthus altissima has been used to settle an upset stomach, to alleviate a fever and as an insecticide. We reported that the water extract of A. altissima induced apoptotic cell death in Jurkat T-acute Iymphoblastic leukemia cells. Here, we showed the dose-dependent inhibitions of cell viability by the extract, as measured by cell morphology. The cell cycle control genes are considered to play important roles in tumorigenesis. The purpose of the present study is also to investigate the effect of A. altissima on cell cycle progression and its molecular mechanism in the cells. The level of p21 protein was increased after treatment of the extract, whereas both Bcl-2 and Bax protein levels were not changed. These results suggest that A. altissima induces apoptotic cell death via p21-dependent signaling pathway in Jurkat cells which delete wild type p53. Gl checkpoint related gene products tested (cyclin D3, cyclin dependent kinase 4, retinoblastoma, E2Fl) were decreased in their protein levels in a dose-dependent manner after treatment of the extract Taken together, these results indicate that the increase of apoptotic cell death by A. altissima may be due to the inhibition of cell cycle in Jurkat cells.

• IMMUNE NETWORK
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• v.6 no.1
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• pp.1-5
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• 2006

Background: B cell subset has been divided into B-1 cells and B-2 cells. B-1 cells are found most prominently in the peritoneal cavity, as well as constituting a small pro portion of splenic B cells and they are larger and less dense than B-2 cells in morphology. This study was designed to compare the differences in their proliferation and differentiation between B-1 and B-2 cell. Methods: We obtained sorted B-1 cells from peritoneal fluid and B-2 cells from spleens of mice. Secreted IgM was measured by enzyme-linked immunosorbent assay. Entering of S phase in response to LPS-stimuli was measured by proliferative assay. Cell cycle analysis by propidium iodide was performed. p21 expression was assessed by real time PCR. Results: Cell proliferation and cell cycle progression in B-1 and B-2 cells, which did not occur in the absence of LPS, required LPS stimulation. After LPS stimulation, B-1 and B-2 cells were shifted to Sand G2/M phases. p21 expression by resting B-1 cells was higher than that of resting B-2 cells. Conclusion: B-1 cells differ from conventional B-2 cells in proliferation, differentiation and cell cycle.