• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.10
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• pp.865-871
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• 2016

In recent years, traditional scaffold fabrication techniques such as gas foaming, salt leaching, sponge replica, and freeze casting in tissue engineering have significantly limited sufficient mechanical property and cell interaction effect due to only random pores. Fused deposition modeling is the most apposite technology for fabricating the 3D scaffolds using the polymeric materials in tissue engineering application. In this study, 3D slurry mould was fabricated with a blended biphasic calcium phosphate (BCP)/Silica/Alginic acid sodium salt slurry in PCL mould and heated for two hours at $100^{\circ}C$ to harden the blended slurry. 3D dual-pore BCP/Silica scaffold, composed of macro pores interconnected with micro pores, was successfully fabricated by sintering at furnace of $1100^{\circ}C$. Surface morphology and 3D shape of dual-pore BCP/Silica scaffold from scanning electron microscopy were observed. Also, the mechanical properties of 3D BCP/Silica scaffold, according to blending ratio of alginic acid sodium salt, were evaluated through compression test.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1700-1703
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• 2008

The purpose of this study was to examine the effects of various mechanical stimuli for MC3T3-E1 cells. Among the several mechanical stimulations, we focused on compressive stain and ultrasound. In this study, we developed a bioreactor capable of applying controlled stimuli to scaffolds. PLLA/PCL scaffold was fabricated by using salt-leaching method. We performed dynamic cell culture using preosteoblasts MC3T3-E1 cells with 1MHz, 30mW/cm2 ultrasound and 10% of compressive strain. Result of CCK-8 analysis at 1, 4, 7, 10 days showed that mechanical stimuli had no significant effect for cell proliferation. However, those stimuli influenced ALP(Alkaline phopatase) activity, which is one of differentiation marker.

• Tissue Engineering and Regenerative Medicine
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• v.15 no.6
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• pp.735-750
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• 2018

BACKGROUND: The major challenge of tissue engineering is to develop constructions with suitable properties which would mimic the natural extracellular matrix to induce the proliferation and differentiation of cells. Poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone) (PCL-PEG-PCL, PCEC), chitosan (CS), nano-silica ($n-SiO_2$) and nano-hydroxyapatite (n-HA) are biomaterials successfully applied for the preparation of 3D structures appropriate for tissue engineering. METHODS: We evaluated the effect of n-HA and $n-SiO_2$ incorporated PCEC-CS nanofibers on physical properties and osteogenic differentiation of human dental pulp stem cells (hDPSCs). Fourier transform infrared spectroscopy, field emission scanning electron microscope, transmission electron microscope, thermogravimetric analysis, contact angle and mechanical test were applied to evaluate the physicochemical properties of nanofibers. Cell adhesion and proliferation of hDPSCs and their osteoblastic differentiation on nanofibers were assessed using MTT assay, DAPI staining, alizarin red S staining, and QRT-PCR assay. RESULTS: All the samples demonstrated bead-less morphologies with an average diameter in the range of 190-260 nm. The mechanical test studies showed that scaffolds incorporated with n-HA had a higher tensile strength than ones incorporated with $n-SiO_2$. While the hydrophilicity of $n-SiO_2$ incorporated PCEC-CS nanofibers was higher than that of samples enriched with n-HA. Cell adhesion and proliferation studies showed that n-HA incorporated nanofibers were slightly superior to $n-SiO_2$ incorporated ones. Alizarin red S staining and QRT-PCR analysis confirmed the osteogenic differentiation of hDPSCs on PCEC-CS nanofibers incorporated with n-HA and $n-SiO_2$. CONCLUSION: Compared to other groups, PCEC-CS nanofibers incorporated with 15 wt% n-HA were able to support more cell adhesion and differentiation, thus are better candidates for bone tissue engineering applications.

• Biomolecules & Therapeutics
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• v.12 no.1
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• pp.9-18
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• 2004

Opening of the mitochondrial permeability transition pore has been recognized to be involved in cell death. The present study investigated the effect of ${\beta}$-carbolines (harmaline and harmalol) and deprenyl on the dopamine-induced change in the mitochondrial membrane permeability and cell death in differentiated PC12 cells. Cell death due to 250 4{\mu}$M dopamine was inhibited by caspase inhibitors (z-IETD.fmk, z-LEHD.fmk and z-DQMD.fmk) and antioxidants (N-acetylcysteine, ascorbate, superoxide dismutase, catalase and carboxy-PTIO). ${\beta}$-Carbolines prevented the dopamine-induced cell death in PCl2 cells, while deprenyl did not inhibit cell death. ${\beta}$-Carbolines decreased the condensation and fragmentation of nuclei caused by dopamine in PC12 cells. ${\beta}$-Carbolines inhibited the decrease in mitochondrial transmembrane potential, cytochrome c release, formation of reactive oxygen species and depletion of GSH caused by dopamine in PC12 cells, whereas deprenyl did not decrease dopamine-induced mitochondrial damage. ${\beta}$-Carbolines, deprenyl and antioxidants depressed the formation of nitric oxide and melanin in dopamine-treated PC12 cells. The results suggest that cell death due to dopamine PC12 cells is mediated by caspase-8, -9 and -3. Unlike deprenyl, ${\beta}$-carbolines may attenuate the dopamineinduced cell death in PC12 cells by suppressing change in the mitochondrial membrane permeability through inhibition of the toxic action of reactive oxygen and nitrogen species.

• Journal of Life Science
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• v.18 no.3
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• pp.329-335
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• 2008

Korean Deep ground sea-like water (KDSW) has a similar mineral composition with deep sea water. KDSW has demonstrated its usefulness and attracted in the medical fields. KDSW and Danasoo (desalted deep ground sea-like water) intake improve antioxidant, antidiabetic activity and immunity. Antioxidant activities of KDSW and Dnansoo were measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical, superoxide dismutase-like activity (SODA) and photochemiluminescence (PCL). DPPH radical scavenging and SOD-like activities of KDSW and Danasoo were remarkably increased in a dose-dependent manner. Antioxidant activities of KDSW and Danasoo 85.32 and 14.02 nmol of ascorbic acid equivalent/ml KDSW and Danasoo, respectively, using the PCL method. Lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophages RAW264.7 cells was inhibited up to 30% by treatment with Danasoo (20%). NO is synthesized by the enzyme of nitric oxide synthase (NOS) and plays an important role tumor growth and angiogenesis. The anticancer effects of Danasoo on human gastric and lung cancer cells was performed by levels of inducible nitric oxide synthase (iNOS). Danasoo significantly reduced iNOS expression of human gastric cancer (SNU-l) and lung carcinoma (A549). The serum glucose level was significantly reduced by Danasoo (20%) diet in streptozotocin (STZ)-induced diabetic rats. These result suggest that KDSW has excellent biological activities and thus it has great potential as a source for natural health products.

• Archives of Plastic Surgery
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• v.47 no.4
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• pp.310-316
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• 2020

Background To produce patient-specific nasal implants, it is necessary to harvest and grow autologous cartilage. It is crucial to the proliferation and growth of these cells for scaffolds similar to the extracellular matrix to be prepared. The pore size of the scaffold is critical to cell growth and interaction. Thus, the goal of this study was to determine the optimal pore size for the growth of chondrocytes and fibroblasts. Methods Porous disc-shaped scaffolds with 100-, 200-, 300-, and 400-㎛ pores were produced using polycaprolactone (PCL). Chondrocytes and fibroblasts were cultured after seeding the scaffolds with these cells, and morphologic evaluation was performed on days 2, 14, 28, and 56 after cell seeding. On each of those days, the number of viable cells was evaluated quantitatively using an MTT assay. Results The number of cells had moderately increased by day 28. This increase was noteworthy for the 300- and 400-㎛ pore sizes for fibroblasts; otherwise, no remarkable difference was observed at any size except the 100-㎛ pore size for chondrocytes. By day 56, the number of cells was observed to increase with pore size, and the number of chondrocytes had markedly increased at the 400-㎛ pore size. The findings of the morphologic evaluation were consistent with those of the quantitative evaluation. Conclusions Experiments using disc-type PCL scaffolds showed (via both morphologic and quantitative analysis) that chondrocytes and fibroblasts proliferated most extensively at the 400-㎛ pore size in 56 days of culture.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.95-95
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• 1995

뇌신경 변성 / 퇴행과 관련된 중요한 병인론 중의 하나는 변성 과정에서 형성된 유리기(free radical)로 인한 항산화계의 평형 소실로 알려져 있다. Aspalatone (APT)의 예상되는 항산화 효능을 검정하기 위하여 본 실험에서는 Kainic acid (KA) 유발 뇌변성 모델을 적용하였다. KA 모델은 변연계의 간질성 경련과 신경세포 변성에 대하여 재현성 있는 병변 모델을 제공해 주며, 이와 같은 신경세포의 병독 기전에 산소 유리기가 관여함이 강력히 시사되고 있기 때문이다. KA 투여로 인하여 지속적이고도 전형적인 간질성 경련이 관찰되고 1일 이내에 높은 치사율을 보였으나 APT으로 인하여 그 간질성 경련 행위와 비율이 억제되고 KA 유발 치사율도 억제되었다. 최종 KA 투여 3일 후에 얻어진 흰쥐 해마 및 대뇌 피질에서 항산화 효소인 Superoxide dismutase (SOD), Catalase (Cat.), Glutathione peroxidase (GSH-PX) 및 과산화지질의 지표인 Malondialdehyde (MDA)를 검정하였다. 대조군에 비하여 KA는 뇌조직의 SOD-1을 유도하였으나, Cat.와 GSH-PX의 활성은 현저히 유도되지 않았고, 반면에 MDA 치는 현저히 증가하였다. 즉, Cat., GSH-PX와 같은 $H_2O$$_2$중화제가 동반 유도하지 않는 SOD의 유도는 세포내 축적되는 $H_2O$$_2$로 인하여 Fenton/Haber-Weiss 반응을 가속화하여 과산화지질화를 촉진함을 시사한다. APT 병용 투여로 SOD는 현저히 유도되지 않았으나 특히 Cat.가 현저히 유도되어지고 MDA는 억제되었다. 이와 같은 생화학적인 결과는 다음의 형태학적인 소견과 일치한다. Fos 관련 항원 (FRA)와 SOD-1을 면역세포화학 (Immunocytochemistry)적 방법으로 이중 표식 (double-labelling) 하였다. FRA는 KA로 인한 신경세포의 자극에 대한 지표로 응용하였고, SOD-1은 퇴행성 뇌질환에서 산화적 손상의 지표로 사용하였다. KA 투여로 해마의 dentate gyrus (DG) 내에 강한 면역환성 (immunoreactivity)이 나타났고 pyramidal cell layer (PCL)와 glia에 SOD-1이 강하게 염색되었다. APT 병용 투여로 상당수의 경련이 일어나지 않은 흰쥐는 해마의 DG에 FRA가 경미하게 염색되었고, PCL에 SOD-1도 경미하게 나타났으나, 경련이 나타난 쥐에서는 KA만을 투여한 흰쥐와 구별되지 않았다. 이상의 APT의 항산화 효과는 KA로 인한 뇌세포 변성 개선에 중요한 인자로 작용할 것으로 사료되나, 보다 명확한 APT의 기전을 검색하고 직접 임상에 응응하기 위하여는 보다 다양한 실험 조건이 보완되어야 찰 것으로 생각된다.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.327-334
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• 2013

For the development of hardy kiwi wine, we arranged for the post-maturity of hardy kiwi fruit, treated them with calcium carbonate and a pectinase enzyme complex, investigated the resulting physicochemical properties and conducted a sensory evaluation. The period determined for creating post-maturity in the hardy kiwi fruit was determined as 5 days storage at room temperature following maturity. During this time the yield of fruit juice was increased from 22.1% to 53.5% using 0.1% (v/v) cytolase PCL5 for 2 h at room temperature. 0.1% (w/v) calcium carbonate was also added during the process of aging, for the reduction of the sour taste. The fermentation trial of the hardy kiwi wine was prepared using water (25% or 50%), sugar ($24^{\circ}brix$), 0.1% (w/v) $CaCO_3$, 0.1% (v/v) cytolase PCL5, $K_2S_2O_5$ (200 ppm), and yeast ($1.5{\times}10^7$ cell/ml). Fermentation then occurred for 2 weeks at $20^{\circ}C$. The pH value, total acidity, alcohol, and reducing sugar content of the resulting hardy kiwi wines of 25% (v/w) and 50% (v/w) water, were in a range of pH 3.4-3.7, 1.12-1.21%, 14.3-14.4%, and 15-16 g/l, respectively. Citric acid and fructose constituted the major organic acids and the free sugar of the 25% and 50% hardy kiwi wine, respectively. Volatile flavor components, including 10 kinds of esters, 8 kinds of alcohols, 5 kinds of acids, 3 kinds of others and aldehydes, were determined by GC analysis. The results of sensory evaluation demonstrated that 50% hardy kiwi wine is more palatable than 25% hardy kiwi wine.

• The Journal of the Korean bone and joint tumor society
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• v.20 no.2
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• pp.85-88
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• 2014

Localized forms of giant cell tumor are known to arise commonly in the synovial membrane of the finger joints. Multinucleated giant cells are its characteristic pathology finding, giant cell tumor shows a low rate of recurrence after complete excision. When occurring at the knee joints, giant cell tumor manifests a wide form of symptoms, from no symptom at all, to intermittent locking. Complete excision is possible by arthroscopy, but if done incompletely, it is reported to recur in 45% of cases. We present here a case of giant cell tumor that has arisen from the anterior portion of the posterior cruciate ligament, excised by arthroscopy and followed by pathologic confirmation.

• Food Science and Preservation
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• v.1 no.1
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• pp.37-43
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• 1994

A microcomputer system consisting of 16-bit microcomputer, PCL-711S interface board, censors, and converters have been set up in order to automatically measure temperature, humidity and weight loss which are major variables of storage of apple. This system was operated by PC-LabDAS software. It has been possible to measure continuously the weight loss of Fuji apple stored in CA with the weight converter made by a miniature load cell and a strain amplifier. The temperature was checked by a k-type thermocouple and Pt 100 $\Omega$ RTD, and humidity by PQ653JAl humidity sensor. It has been possible to set up a linear equation which showers high correlationship between the estimate of temperature, weight humidity and the output of the converter in that r2 is more than 0.99. Transpiration rate, a significant factor of quality deterioration for CA storage of apple, can be estimated with these values.