• Applied Chemistry for Engineering
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• v.31 no.1
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• pp.13-18
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• 2020

Iron oxide nanoparticles were microencapsulated using fibroin, a protein polymer of silk fiber, for theragnostic applications. The content of iron oxide was determined to be 4.28% by thermogravimetric analysis and 5.11% by magnetometer. A suspension of murine fibroblast 3T3 cells grown in medium supplemented with iron oxide-microcapsules turned clear in response to the magnetic force and the cells aggregated to the magnet direction. Neodymium magnets placed on the top of the culture dish, and attracted cells to the center of the culture surface. The cells collected on the culture surface aggregated to form a rough spheroid of 2 mm in a diameter after 72 h. In the outer layer of the cell aggregate, cells were relatively large and gathered together to form a dense tissue, but the central part was observed to undergo cell death due to the mass transfer restriction. In the outer layer, iron oxide-microcapsules were lined up like chains in the direction of magnetic force. Using microCT, it was demonstrated that the iron oxides inside the cell aggregate were not evenly distributed but biased to the magnetic direction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.5
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• pp.293-300
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• 2021

In this study, the microstructure and thermal conductivity correlation was investigated for concrete materials used in concrete thermal energy storage (CTES) among real-time energy storage devices. Graphite was used as admixture to increase the thermal conductivity performance of the CTES. Concrete specimens of 10% and 15% substitution of cement by mass with graphite, as well as ordinary portland cement (OPC) specimens were prepared, and the microstructural changes and effects on thermal conductivity were analyzed. Porosities of OPC and concrete with graphite were compared using micro-CT, and the microstructural characteristics were quantified using probability functions. Three-dimensional virtual specimens were constructed for thermal analysis, to confirm the effect of microstructural characteristics on thermal conductivity, and the results were compared with the measured conductivity obtained using the hot-disc method. To identify thermal conductivity of graphite for thermal analysis, solid phase conductivity was inversely determined based on simulation and experimental results, and the effect of graphite on thermal conductivity was analyzed.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.169-177
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• 2018

Glass fiber reinforced polyester (GFRP) composites are widely used as structural materials in harsh environment such as underground pipes, tanks and boat hulls, which requires long-term water resistance. Especially, these materials might be damaged due to delamination between gelcoat and composites through an osmotic process when they are immersed in water. In this study, GFRP laminates were prepared by surface treatment of UPE (unsaturated polyester) gelcoat by vacuum infusion process to improve the durability of composite materials used in underground pipes. The composite surface coated with gelcoat was examined for surface defects, cracking, and hardness change characteristics in water-immersion environments (different temperatures of $60^{\circ}C$, $75^{\circ}C$, and $85^{\circ}C$). The penetration depth of cracks was investigated by micro CT imaging according to water immersion temperature. It was confirmed that cracks developed into the composites material at $75^{\circ}C$ and $85^{\circ}C$ causing loss of durability of the materials. The point at which the initial crack initiated was defined as the failure time and the life expectancy at $23^{\circ}C$ was measured using the Arrhenius equation. The results from this study is expected to be applied to reliability evaluation of various industrial fields where gelcoat is applied such as civil engineering, construction, and marine industry.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.8.1-8.8
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• 2017

Background: For an effective bone graft for reconstruction of the maxillofacial region, an adequate vascular network will be required to supply blood, osteoprogenitor cells, and growth factors. We previously reported that the secretomes of bone marrow-derived mesenchymal stem cells (MSC-CM) contain numerous growth factors such as insulin-like growth factor (IGF)-1, transforming growth factor $(TGF)-{\beta}1$, and vascular endothelial growth factor (VEGF), which can affect the cellular characteristics and behavior of regenerating bone cells. We hypothesized that angiogenesis is an important step for bone regeneration, and VEGF is one of the crucial factors in MSC-CM that would enhance its osteogenic potential. In the present study, we focused on VEGF in MSC-CM and evaluated the angiogenic and osteogenic potentials of MSC-CM for bone regeneration. Methods: Cytokines in MSC-CM were measured by enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs) were cultured with MSC-CM or MSC-CM with anti-VEGF antibody (MSC-CM + anti-VEGF) for neutralization, and tube formation was evaluated. For the evaluation of bone and blood vessel formation with micro-computed tomography (micro-CT) and for the histological and immunohistochemical analyses, a rat calvarial bone defect model was used. Results: The concentrations of IGF-1, VEGF, and $TGF-{\beta}1$ in MSC-CM were $1515.6{\pm}211.8pg/mL$, $465.8{\pm}108.8pg/mL$, and $339.8{\pm}14.4pg/mL$, respectively. Tube formation of HUVECs, bone formation, and blood vessel formation were increased in the MSC-CM group but decreased in the MSC-CM + anti-VEGF group. Histological findings suggested that new bone formation in the entire defect was observed in the MSC-CM group although it was decreased in the MSC-CM + anti-VEGF group. Immunohistochemistry indicated that angiogenesis and migration of endogenous stem cells were much more abundant in the MSC-CM group than in the MSC-CM + anti-VEGF group. Conclusions: VEGF is considered a crucial factor in MSC-CM, and MSC-CM is proposed to be an adequate therapeutic agent for bone regeneration with angiogenesis.

• Journal of Digital Convergence
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• v.11 no.9
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• pp.365-370
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• 2013

This mouse calvarial defected model is frequently used for new scaffold development in the bone regeneration. Most experiments are carried out in this way by measuring the bone regeneration of mouse calvaria defected area. As a next step, hematoxylin and eosin staining is analyzed by sacrificing mice On the other hand, the quantitative analysis for bone regeneration is carried out by micro computed tomography. However, there are several drawbacks with the micro computed tomography. That is, it takes a long time and it is quite expensive for bone regeneration quantitative analysis. This study was performed by simply measuring the quantity of bone regeneration in mouse clavaira defected area on two-dimensional digital x-ray images via Image J. Consequentially, this experimental method by using J program might help bio-technologist researcher regarding new bone regeneration by comparing the quantity of bone regeneration quickly and precisely as well.

• Journal of Korean Medicine Rehabilitation
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• v.24 no.1
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• pp.31-45
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• 2014

Objectives This study intends to clarify how Leejung-tang (here in after reffered to LJT) affect Wistar Rat whose osteoarthritis was induced by MIA. Methods Osteoarthritis was induced into rat by injecting MIA in its knee joint. Rats are divided into a total of 4 groups (n=6). Normal group are not treated at all without inducing osteoarthritis whereas control group were induced for osteoarthritis by MIA and oral medicated with 2 ml of physiological saline per day. Positive comparison group (Indomethacin) was injected with MIA and after 7 days, 2 mg/kg of Indomethacin was medicated. Experimental group (LJT) was injected with MIA and after 7 days that was medicated with 23 mg/kg of LJT. Indomethacin and LJT were oral medicated for each substance a total of 4 weeks with one time per day. After experiments (from 1 week after injection of MIA to 4 weeks elapsed), Hind paw weight bearing ability, Functions of liver and kidney, Serum prostaglandin $E_2$, TNF-${\alpha}$, IL-1${\beta}$, IL-6, Osteocalcin, TIMP-1, MMP-9, LTB4 and amount of cartilage were measured and histopathological variations for knee joint structures were observed. Results 1) Hind paw weight bearing ability of LJT administration group was increased but there was no statistical significance. 2) Functions of liver and kidney were not affected. 3) Serum prostaglandin $E_2$, IL-1${\beta}$, Osteocalcin, MMP-9 were significantly decreased and TNF-$\alpha$, IL-6, TIMP-1, LTB4 were also decreased but there were no statistical significance. 4) In H&E staining and Safranin-O staining, there were small histopathological changes in LJT administration group than control group. 5) In micro CT (computed tomography)-arthrography, cartilage destruction was more suppressed in LJT administration group than control group. Conclusions Based on all results mentioned above, Leejung-tang (LJT) is believed to be meaningful for suppressing the progress of osteoarthritis and its treatments because of its anti-inflammatory effects and alleviation of pain with histopathological effective efficacy.

• Korean Journal of Materials Research
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• v.20 no.6
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• pp.312-318
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• 2010

Multilayer Poly methyl methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates were fabricated using electrospinning and in vitro investigations were carried out for pre-clinical biocompatibility studies. The initial cellular cytotoxicity of the methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using fibroblast-like L-929 cells. Cellular adhesion and differentiation studies were carried out using osteoblast-like MG-63 cells. As simulated body fluid (SBF) contains the same ionic concentration of body fluid and any bioactive material tends to deposit bone-like apatite on the samples surfaces into the SBF, in vitro bioactivity of the multilayer bone plates were investigated using SBF. We also studied the internal organization and tensile strength of the multilayer PMMA/PVA bone plates using micro-computed topography (${\mu}$-CT) and universal testing instrument (UTI, Korea) respectively. The cellular cytotoxicity study with MTT confirmed that the cellular viability was 78 to 90% which indicates good cyto-compatibility. Scanning electron microscopic findings revealed a good attachment and adhesion phenomenon of MG-63 cells onto the surfaces of the samples. Cellular differentiation studies also showed that osteogenic differentiation was switched on in a timely manner and affirmed along with that of the control group. Bone-like apatite formation on the surfaces was confirmed within 14 days of SBF incubation. Initial organizations of the multilayer PMMA/PVA bone plates were characterized as dense and uniform. The tensile strength of the post-pressing electronspun mat was higher than that of the pre-electronspun mat. These results suggest that a multilayer PMMA/PVA bone plate system is biocompatible, bioactive and a very good alternative bone plate system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.1
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• pp.46-51
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• 2017

The aim of this study is to investigate anti-arthritis activity using a KV pharmacopuncture. KV pharmacopuncture was inserted at BL40 for 4 weeks to SD-Rat, where arthritis was induced by monosodium iodoacetate (MIA) at 60 mg/ml. MMP-9, CTX II, LTB4, calcitonin and glycosaminoglycan level in serum were measured by ELISA. The cartilage of patella volume was examined and 3-D high-resolution reconstructions of the cartilage of patella were obtained using a Micro-CT system. Also, The histopathological change of knee was observed by H&E and safranin-O staining. Production of MMP-9, CTX II and LTB4 level in serum was decreased, respectively, in comparison with control. The other way, production of calcitonin and glycosaminoglycan level in serum was increased, respectively, in comparison with control. The cartilage of patella volume increased significantly. In addition, the KV group showed a increase in the cartilage volume and proteoglycan. These results may be used a remedy for new korea medicine to ease the symptoms mentioned above.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.212-224
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• 2013

This study intends to clarify how Sayeok-tang(here in after reffered to SYT) affect C57BL/10 mice whose osteoarthritis was induced by papain. Osteoarthritis was induced by injecting papain in the knee joint of 3 groups(n=6) of mice. Normal group was non-treatment group and was not injected papain, whereas control mice were orally administered with $200{\mu}{\ell}$ of physiological saline. Positive comparison group was medicated with 100 mg/kg of Joins$^{(R)}$ mixed with $200{\mu}{\ell}$ of physiological saline. Experimental group was medicated with 400 mg/kg of SYT mixed with $200{\mu}{\ell}$ of physiological saline. Both Positive and experimental comparison groups were orally medicated once per day for 4 weeks. After the experiment, the functions of liver and kidney, inflammation cytokine values within serum, degree of revelation for inflammation cytokine genes, immune cells within blood, metabolism of arachidonic acid and amount of cartilage were measured and histopathological changes in the knee joint structures were observed. As results, SYT had no significant effect on the liver and kidney functions. Interleukin-$1{\beta}$(IL-$1{\beta}$), interleukin-6(IL-6), monocyte chemo attractant protein-1(MCP-1) and tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) were significantly decreased. Inflammation cytokines in joints were all significantly decreased. Prostaglandin $E_2(PGE_2)$, thromboxane $B_2(TXB_2)$ were significantly decreased. Destruction of cartilage on micro computed tomography(CT)-arthrography was meaningfully decreased. In terms of histopathology, infiltration of inflammation, proliferation of synovial membrane, subsidence of cartilage and bone due to penetration of excessive formation of synovial cell and destruction of cartilage were small. Based on all results mentioned above, Sayeok-tang(SYT) is believed to be meaningful for suppressing the progress of osteoarthritis and its treatments because of its anti-inflammatory effects and alleviation of pain with histopathological effective efficacy.

• Analytical Science and Technology
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• v.33 no.1
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• pp.11-22
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• 2020

When extracting semi-volatile components of herbal medicines using hot water vapor, some substances may react with water vapor or oxygen, and some volatile substances may be lost, when using an organic solvent extraction method has the disadvantage that it may contain a non-volatile material and residual organic solvent. In addition, it is inefficient to separate semi-volatile substances from herbal medicines into each single component and conduct biological activity research for each component to determine the effective ingredient, and some components may be lost in the separation process. In this study, semi-volatile substances evaporated under two pressure-reduced conditions in Chinese herbal medicines such as Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were separated by cooling with liquid nitrogen. Those were analyzed by gas chromatography-mass spectrometry (GC-MS) to identify the components, and this method may be used to study biological activities at the cellular level. The substances separated under reduced pressure, essential oil obtained by simultaneous distillation extraction (SDE) method and substances by using solid phase micro-extraction (SPME) from Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were analyzed by GC-MS. In the case of Cnidii Rhizoma and Aucklandiae Radix, there were some differences among the essential oil components obtained by SDE and those identified by low temperature capture (CT) and SPME method, these were believed to be produced by some volatiles reacting with water or oxygen at the boiling point temperature of water.