• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.362-366
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• 2004

Quantitative evaluation of substrates for cells is essential to understanding cell-material adhesive interaction and it is also necessary for the development of new biomaterials. Many cells on adhesive molecules will form an organization of actin into bundles and production of the large, highly organized structures termed focal adhesions. To better understand adhesion formations between cells and substrata, we have quantified the force required to displace attached cell. we allowed rabbit knee chondrocyte to attach on a substratum of microscope slide glass. Our results demonstrate that a force is required to detach cells is changed according to detachment time variation.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.48-50
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• 2002

Cartilage defects are common and painful conditions that affect people of all ages. Although many techniques have developed, none of the current available treatment options is satisfactory. Recent advances in biology and materials science have pushed tissue engineering to the forefront of new cartilage repair techniques. The purpose of this study is to determine effective regeneration method for tissue-engineered cartilage. A serum free medium was developed for cartilage tissue engineering. Chondrocyte passage number was found to influence greatly on cartilage tissue formation in vivo. Injectable, biodegradable polymer matrix was developed for chondrocyte transplantation through injection. Transplantation of chondrocytes mixed with the injectable matrices resulted in the cartilage formation in nude mice's subcutaneous sites and rabbit knees. This study may lead to the development of tissue-engineered cartilage appropriate for clinical applications.

• BMB Reports
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• v.49 no.10
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• pp.548-553
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• 2016

Mesenchymal stem cells (MSCs) are widely used in cartilage tissue engineering to repair articular cartilage defects. However, hypertrophy of chondrocytes derived from MSCs might hinder the stabilization of hyaline cartilage. Thus, it is very important to find a suitable way to maintain the chondrogenic phenotype of chondrocytes. It has been reported that cordycepin has anti-inflammatory and anti-tumor functions. However, the role of cordycepin in chondrocyte hypertrophy remains unclear. Therefore, the objective of this study was to determine the effect of cordycepin on chondrogenesis and chondrocyte hypertrophy in MSCs and ATDC5 cells. Cordycepin upregulated chondrogenic markers including Sox9 and collagen type II while down-regulated hypertrophic markers including Runx2 and collagen type X. Further exploration showed that cordycepin promoted chondrogenesis through inhibiting Nrf2 while activating BMP signaling. Besides, cordycepin suppressed chondrocyte hypertrophy through PI3K/Bapx1 pathway and Notch signaling. Our results indicated cordycepin had the potential to maintain chondrocyte phenotype and reconstruct engineered cartilage.

• 대한정형외과스포츠의학회:학술대회논문집
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• 2005.04a
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• pp.56-62
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• 2005

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.841-848
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• 2008

Archyranthes radix has had extensive therapeutic application, and there has been increasing interest in its biological effects. However, the biochemical effects of Archyranthes radix on chondrocyte oxidative stress have never been systematically investigated. Therefore, we investigated the effects of Acyranthes radix on role of MAPK signal transduction pathway on oxidative stress induced by hydrogen peroxide in rat articular chondrocytes. The statistically significant inhibitory action of Archyranthes radix on cell proliferation was observed at above $5{\mu}g/m{\ell}$. Next, we examined the time-dependent effect of $5{\mu}g/m{\ell}$ Archyranthes radix on cell proliferaion. Archyranthes radix significantly inhibited cell proliferation from 12 hr after treatment (P<0.05). $H_2O_2$, resulted in a time- and dose-dependent cell proliferation, which was largely attributed to oxidative damage. Acyranthes radix and $H_2O_2$ treatment caused marked sustained activation of phosphorylation of ERK1/2. Moreover, the synergistic phosphorylation of p44/42 MAPK by $H_2O_2$ and Archyranthes radix was selectively inhibited by PD 98059, a p44/42 MAPK inhibitor. In conclusion, these results are consistent with the hypothesis that under conditions of oxidative stress, the $H_2O_2$-induced inhibition of cell proliferation in the rat chondrocyte is mediated through a modulation of the Archyranthes radix signaling pathway, promoting further phosphorylation of p44/42 MAPK, indicating a potentially important role in cartilage repair and in the treatment of osteoarthritic cartilage.

• Journal of the Korean Arthroscopy Society
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• v.14 no.1
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• pp.36-40
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• 2010

Autologous chondrocyte implantation is a widely used technique for treating cartilage defect or osteochondral lesion, which is the method of transplantation of self chondrocytes after cultivation in the laboratory. We experienced the rare case of heterotophic ossification in the recipient site of the knee after autologous chondrocyte implantation. So we want to report this case with review of the relevant literatures.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.1
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• pp.132-137
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• 2011

Bee venom acupuncture (BVA), as a kind of herbal acupuncture, involved injecting diluted bee venom into acupoints and is used for pain, osteoarthritis and rheumatoid arthritis patients. BVA is growing in popularity, especially in Korea, and is used primarily for pain relief in many kinds of diseases. However, the effect of bee venom anti-inflammatory related action in lipopolysaccharide (LPS) induced chondrocyte stress have not been reported yet. The aim of this study was to investigate the effect of bee venom of cell viability and inflammatory cytokine in rat articular chondrocyte cultures stimulated with lipopolysaccharide. Inflammation was induced in rat chondrocytes by treatment with $10{\mu}g/m{\ell}$ LPS. The change of cell viability were decreased in chondrocytes after treatment with lipopolysaccharide. The cell viability revealed that BV exerted no significant cytotoxicity in the rat chondrocyte. Bee venom inhibited decreased cell viability in the presence of lipopolysaccharide ($10{\mu}g/m{\ell}$) in a dose dependent manner(0.1, 0.5, 1.0 and $5.0{\mu}g/m{\ell}$) at bee venom(p<0.05). Tumor necrosis factor (TNF)-${\alpha}$ production in the presence of lipopolysaccharide($1{\mu}g/m{\ell}$) was also inhibited in a dose dependent manner (p<0.05 from bee venom $0.1{\mu}g/m{\ell}$). Interleukin (IL)-6 production in the presence of lipopolysaccharide ($10{\mu}g/m{\ell}$) was inhibited as well (p<0.05 at bee venom 0.1, 0.5, 1.0 and $5.0{\mu}g/m{\ell}$, respectively). Our results demonstrate that bee venom was a anti-inflammatory agent of chondrocytes. Bee venom may exert its anti inflammatory effects through inhibition of TNF-${\alpha}$ and IL-6 synthesis, and may then pain relief and reduce the articular destruction.

• Archives of Plastic Surgery
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• v.32 no.5
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• pp.599-606
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• 2005

Clinical application of the cartilage formed by tissue engineering is of no practical use due to the failure of long-term structural integrity maintenance. One of the important factors for integrity maintenance is the biomaterial for a scaffold. The purpose of this study is to evaluate the difference between polylactic-co-glycolic acids (PLGA) and chitosan as scaffolds. Human auricular chondrocytes were isolated, cultured, and seeded on the scaffolds, which were implanted in the back of nude mice. Eight animals were sacrificed at 4, 8, 12, 16, and 24 weeks after implantation respectively. In gross examination and histological findings, the volume of chondrocyte-PLGA complexes was decreased rapidly. The volume of chondrocyte-chitosan complexes was well maintained with a slow decrease rate. The expression of type II collagen protein detected by immunohistochemistry and western blots became weaker with time in the chondrocyte-PLGA complexes. However, the expression in the chondrocyte-chitosan complexes was strong for the whole period. Collagen type II gene expressions using RT-PCR showed a similar pattern. In conclusion, these results suggest that chitosan is a superior scaffold in cartilage tissue engineering in terms of structural integrity maintenance. It is expected that chitosan scaffold may become one of the most useful scaffolds for cartilage tissue engineering.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.33-37
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• 2014

Objective: Low intensity pulsed ultrasound (LIPUS) has been shown to accelerate cell proliferation and tissue healing in both animal models and clinical trials. However, details of the clinical effects of LIPUS have not been well characterized. The aim of this study was to investigate the effect of LIPUS on mitogen-activated protein kinase (MAPK) activation in rat articular chondrocytes. Design: Cross-sectional study. Methods: Chondrocyte were cultured in six well cell culture plates for 72 hours at $37^{\circ}C$ with 5% $CO_2$, and then exposed to LIPUS at 1.5 MHz frequency and $30-mW/cm^2$ power. Changes in chondrocyte activities were evaluated in response to oxydative stress in dose-dependent (0 and 300 uM) and time-dependent (0-24 hr) manner. The cell viability were analyzed using MTT [3-(4.5-dimethylthiazol-2-yl)-2.5 diphenyltetrazolium bromide]. The expression of p38 MAPK was measured using western blotting. Results: Oxidative stress was induced in rat chondrocytes using hydrogen peroxide ($H_2O_2$). The cell viability was decreased in chondrocytes after the $H_2O_2$ dose and time-dependent treatment. The p38 MAPK phosphorylation occurred at a significantly increased rate after $H_2O_2$ treated (p<0.05). Expression of p38 MAPK was decreased in the p38 inhibitor groups compared with the oxidative stress-induced chondrocyte damage via the p38 MAPK signaling pathways (p<0.05). Conclusions: It could be concluded that LIPUS can inhibit oxidative stress-induced chondrocyte damage via the p38 MAPK signaling pathways.

• Applied Microscopy
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• v.26 no.2
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• pp.197-206
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• 1996

cis-Dichlorodiammineplatinum (II) (cis-Platin) inhibits the proliferation and growth of the tumor cells by way of inhibiting DNA and protein synthesis of the cancer cells. Although cis-Platin is very effective antitumor drug, it also produces many other side effects. Thus the author has studied the effects of cis-Platin on the proximal epiphyseal plate in the tibia of the rat. The results were as follows: In the chondrocyte of the proliferative zone, sacculated, and fragmented cisternae of rough endoplasmic reticulum, some mitochondria with disorganized mitochondrial cristae and distorted procollagens were observed, and in the matrix some large matrix granules and dispersed collagen fibrils were revealed on the 1st, 3rd day and 1st week group of cis-Platin treated rats. In the chondrocyte of the proliferative zone of cis-Platin treated rats on the 2nd and 3rd week group, parallely arranged rough endoplasmic reticulum and many procollagens were shown, and in the matrix a number of large matrix granules and many small matrical granules as well as collagen fibrils were revealed. Consequently it is suggested that though cis-Platin induces the degenerative changes of the chondrocyte resulting in components of the cartilagenous matrix, these toxic effects are regressed with time.