• Journal of the Korean Applied Science and Technology
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• v.41 no.4
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• pp.920-928
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• 2024

This study evaluates the balance between cellular removal and extracellular matrix (ECM) preservation in cardiac tissue engineering by comparing chemical and physical decellularization methods. Cardiac tissues were treated with chemical agents (sodium dodecyl sulfate and Triton X-100) and physical methods (freeze-thawing and ultrasound). These methods were assessed based on residual cellular content, DNA quantification, ECM structural integrity, and preservation of key ECM components like collagen and glycosaminoglycan (GAG). The results revealed that while chemical methods, particularly SDS, achieved more complete cell removal, they significantly compromised ECM integrity. In contrast, physical methods, such as freeze-thawing, preserved ECM structure more effectively, despite moderate cellular removal. The findings underscore the importance of tailoring decellularization techniques to specific cardiac tissue engineering needs, with chemical methods excelling in cell removal and physical methods offering superior ECM preservation. Future research should aim to optimize these methods to achieve a better balance between decellularization efficiency and ECM integrity.

• Journal of Acupuncture Research
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• v.27 no.4
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• pp.39-53
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• 2010

목적 : 퇴행성 관절염은 염증성 사이토카인인 IL-$1\beta$에 의해 연골관절이 파괴되고 이로 인해 염증성 사이토카인이 더욱 증가하는 질환이다. 퇴행성 관절염을 치료하기 위해서는 연골 파괴를 가속화시키는 catabolic cytokines의 활성을 줄이고, 성장인자인 anabolic factor의 활성을 증가시는 연골 보호 작용이 있어야 한다. 본 연구에서는 독활 승마 처방(OAH19T)이 catabolic/anabolic 대사 조절에 어떤 영향을 미치는지와 그 신호 전달 기전에 대해 연구하였다. 또한 OAH19T를 구성하는 단미재 및 임상에서 사용되는 COX-2 inhibitor인 Celebrex(CEL)와 효능을 비교 실험하였다. 방법 : 배양된 세포에 IL-$1\beta$로 자극한 후 (1) glycosaminoglycan(GAG)의 분해 억제 정도, (2) OAH19T와 CEL에 대하여 MMP-1과 MMP-3의 유전자 발현 및 활성 억제, (3) Aggrecan 및 Aggrecanases의 유전자 발현 및 활성 억제, (4) OAH19T의 growth factor의 조절 능력, (5) MAPK pathway 등을 RT-PCR(reverse transcriptase-polymerase chain reaction), ELISA(Enzyme-linked immunosorbent assay), western blot, viability 측정을 통해 검증했다. 결과 : 사람 관절 세포에서 (1) 독활 승마 각각의 단미재, 임상에서 사용중인 셀레콕시브(CEL), 조인스보다 실험 약물(OAH19T)이 저농도에서 GAG 분해 억제 효과가 우수하였고, 부탄올로 분획한 OAH19B와는 동등한 효과를 보였다. (2) OAH19T는 IL-$1\beta$에 의하여 활성화된 MMP-1과 MMP-3의 발현을 모두 억제하였으나, CEL은 MMP-1의 발현은 억제하였으나 MMP-3의 발현은 억제하지 못하였다. (3) OAH19T는 IL-$1\beta$에 의하여 손상된 Aggrecan을 회복시켰으며 이는 활성화된 Aggrecanase-1과 Aggrecanase-2를 억제시킴으로써 나타난 결과이다. 그러나 CEL의 경우, 손상된 Aggrecan을 회복시키지 못하였다. (4) 배양된 세포는 IL-$1\beta$에 의하여 TGF-$\beta$II및 TGF-$\beta$ receptor II의 발현이 억제되었으나, OAH19T는 TGF-$\beta$II및 TGF-$\beta$ receptor II의 발현을 회복시켜 OAH19T가 anabolic한 조절능력이 있음을 시사한다. 그러나 CEL의 경우 growth factor에 대한 조절 능력이 없었다. (5) 대사 조절 작용에 대한 기전으로서 MAPK pathway에 대해서 연구한 결과 IL-$1\beta$에 의하여 유도된 pERK, pp38 kinase의 활성은 억제하였고, pJNK의 활성은 변하지 않았다. 또한 OAH19T는 연골 세포에 독성이 없었으며 IL-$1\beta$에 의해 유도된 세포 증식만을 억제시켰다. 이 결과로, OAH19T가 OA chondrocyte의 탈분화 및 세포 고사를 억제하여 연골보호 및 회복 효과가 있음을 알 수 있었다. 결론 : OAH19T는 이를 구성하는 단미재 및 CEL보다 연골보호 효과가 월등하였고, 이러한 연골보호 효과는 catabolic cytokines/growth factors의 균형으로 대사조절을 통해 연골세포의 탈분화 및 세포 고사를 억제하여 연골보호 및 회복 효과가 있음을 알 수 있었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.634-641
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• 2016

The objective of this research was to investigate the in vivo effects of treatment with mulberry extract complex (MEC) on cartilage degeneration and pain severity in an experimental model of rat degenerative arthritis. Monosodium iodoacetate ($2mg/50{\mu}L$) was injected into right knee joints of rats, followed by administration of MEC for 8 weeks at 400 mg/kg or 800 mg/kg of body weight. The experimental data show that treatment with MEC inhibited degradation of glycosaminoglycan and collagen in cartilage. On the other hand, concentrations of cartilage oligomeric matrix protein, C-terminal telopeptide-2, matrix metalloproteinase (MMP)-2, MMP-9, and MMP-13 in serum decreased in comparison with the control. The MEC at all dose levels could inhibit formation of xylene-induced ear edema. In this study, MEC demonstrated significant anti-arthritis activity, which is required for improvement of degenerative arthritis. Based on these results, MEC may be employed for the development of new health foods to ease symptoms of degenerative arthritis.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.512-519
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• 2007

The purpose of this study is to investigate the potential of a novel tissue engineering approach to regenerate intervertebral disc. In this study, thermosensitive scaffold (chitosan-Pluronic hydrogel) and nanofiber were used to replace the nucleus pulposus (NP) and annulus fibrosus of a degenerated intervertebral disc, leading to an eventual regeneration of the disc using the minimally invasive surgical procedure and organ culture. In preliminary study, disc cells were seeded into the scaffolds and cellular responses were assessed by MTT assay and scanning electron microscopy (SEM). Based on these results, we could know that tissue engineered scaffolds might provide favorable environments for the regeneration of tissues. Organ culture was performed in fresh porcine spinal motion segments with endplates on both sides. These spinal motion segments were classified into three groups: control (Intact), injured NP (Defect), and inserting tissue engineered scaffolds (Insert). The specimens were cultivated for 7 days, subsequently structural stability, cell proliferation and morphological changes were evaluated by the relaxation time, quantity of DNA, GAG and histological examination. In these results, inserting group showed higher relaxation time, reduced decrement of DNA contents, and accumulated GAG amount. Consequently, the tissue engineered scaffolds used in this study seen to be a promising base scaffolds for regenerative intervertebral disc due to its capacity to absorb external dynamic loading and the possible ideal environment provided for disc cell growing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.641-645
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• 2004

Crude chondroitin sulfates extracted from midduck tunics (Styela clava) and munggae tunics (Halocynthia roretzi) were examined in vivo in order to be utilized as a cosmetic material which was followed by an in vitro assay. Examinations, such as acute oral toxicity, skin sensitization, acute eye irritation, and primary skin irritation, were peformed with a variety of laboratory animals. Phototoxic and photosensitization tests were not conducted since all chondroitin sulfates failed to absorb U.V. light at the range of 280 to 420 nm. In acute dermal and eye irritation, both specific clinical signs and dead cases were not demonstrated during the test period, but crude chondroitin sulfates from midduck and munggae tunics, and standard chondroitin sulfate from bovine trachea were showed 2.5, 1 and 1.25 of acute ocular irritation index (A.O.I.), respectively. In the case of skin sensitization, crude chondroitin sulfate from midduck tunics exhibited neither specific clinical signs nor dead cases in the entire course of the examination. While in acute oral toxicity, crude chondroitin sulfates from both midduck and munggae tunics found neither specific clinical signs nor dead cases during the test, and LD50 was suspected to be over 2 g/kg. Based on this study, it was proven that crude chondroitin sulfates from either midduck or munggae tunics can be used safely as a cosmetic material.

• Journal of Veterinary Clinics
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• v.32 no.3
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• pp.224-230
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• 2015

This study was designed in the fabricated poly (L-Lactic-co-${\varepsilon}$-Caprolactone) (PLCL) scaffold using chitosan-alginate hydrogel, which would be more suitable to maintain the biological and physiological functions continuing three dimensional spatial organizations for chondrocytes. As a scaffold, hydrogels alone is weak at endure complex loading within the body. In this study, we made cell hybrid scaffold constructs with poly (L-Lactic-co-${\varepsilon}$-Caprolactone) (PLCL) scaffold and hydrogels to make a three-dimensional composition of cells and extracellular matrix, which would be a mimic of a native cartilage. Using a particle leaching technique with NaCl, we fabricated a highly-elastic scaffold from PLCL with 85% porosity and $300-500{\mu}m$ pore size. A mixture of bovine chondrocytes and chitosan-alginate gel was seeded and compared with alginate as a control on the PLCL scaffold. The cell maturation, proliferation, extracellular matrix synthesis, glycosaminoglycans (sGAG) production and collagen type-II expressions were better in chondrocytes seeded in chitosan-alginate hydrogel than in alginate only. These results indicate that chondrocytes with chitosan-alginate gel on PLCL scaffolds provide an appropriate biomimetic environment for cell proliferation and matrix synthesis, which could successfully be used for cartilage repair and regeneration.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.148-153
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• 2015

This study was performed to compare two opioid drugs with isoflurane and to determine the difference between isoflurane/remifentanil anesthesia and isoflurane/fentanyl anesthesia in terms of the anesthetic effects in beagle dogs. Isoflurane was maintained at 0.5 MAC, and the opioid drug was administered as a constant rate infusion. The anesthesia was maintained for 2 hours, and isoflurane and opioid drugs were discontinued 2 hours later. After discontinuing the anesthetics, the extremity movement time, eye global positioning time, gag reflex time, head up time, sternal recumbency time, standing time, walking time and complete recovery times were recorded for each dog. Both of the studied anesthetic protocols were suitable in beagle dogs because the anesthetic status was well maintained until the end of the procedure, and rapid recovery times were demonstrated in this experiment. And this study shows that the isoflurane/remifentanil group was more reliable than the isoflurane/fentanyl group because the recovery time CV was lower. Therefore, isoflurane/remifentanil combination anesthesia could be a better choice than isoflurane/fentanyl anesthesia if the patient is severely ill and stable recovery time is needed.

• Polymer(Korea)
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• v.37 no.2
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• pp.141-147
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• 2013

Poly(lactide-co-glycolic acid) (PLGA) has been widely used in the drug delivery and tissue engineering applications because of its good mechanical strength and biodegradation profile. However, cell attachment to the scaffold is low compared with that on fibrin although cells can be attached to the polymer surface. In this study, PLGA scaffolds were soaked in cells-fibrin suspension and polymerized with dropping fibrinogen-thrombin solution. Cellular proliferation activity was observed in PLGA/fibrin-seeded costal cartilage cells (CC) on 1, 3, and 7 days using the MTT assay and SEM. The effects of fibrin on the extracellular matrix (ECM) formation were evaluated using CC cell-seeded PLGA/fibrin scaffolds. The PLGA/fibrin scaffolds elicited more production of glycosaminoglycan (GAG) and collagen than the PLGA scaffold. In this study, fibrin incorporated PLGA scaffolds were prepared to evaluate the effects of fibrin on the cell attachment and proliferation in vitro and in vivo. In this result, we confirmed that proliferation of cells in PLGA/fibrin scaffolds were better than in PLGA scaffolds. The PLGA/fibrin scaffolds provide suitable environment for growth and proliferation of costal cartilage cells.

• Polymer(Korea)
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• v.37 no.5
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• pp.632-637
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• 2013

It has been widely accepted that costal cartilage cells (CCs) have more excellent initial proliferation capacity than articular cartilage cells as well as the easiness for isolation and collection. This study demonstrated that CCs might be one of the substitutes for articular cartilage cells by tissue engineered cartilage. Poly(lactic-co-glycolic acid) (PLGA) has been extensively tested and used as scaffold material but it was limited by the low attachment of cells and the induction of inflammatory cells. Base on previous our studies, we confirmed demineralized bone particle (DBP) had the power of the reduction of inflammatory reaction and the stimulation proliferation of cells. We fabricated PLGA scaffold loaded with 10, 20, 40 and 80 wt% DBP and then tested the possibility of the regeneration of cartilage using CCs. Assays of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scanning electron microscope (SEM) carried out to evaluate the attachment and proliferation of CCs in DBP/PLGA scaffolds. Glycosaminoglycan (sGAG) and collagen contents assay were conducted to confirm the effects of DBP on formation of extracellular matrix. This study demonstrated that DBP/PLGA scaffolds showed significant positive effects on cell growth and proliferation due to the vitality of DBP as well as the possibility of the application of CCs for tissue engineered cartilage.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.181-187
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• 2006

In recent years the number of patients waiting for organ transplantation has greatly outpaced the supply of human organs available, which leads to a renewed interest in pig-to-human xenotransplantation as an alternative. However, one of the biggest barriers in the xenotransplantation is presence of porcine endogenous retroviruses(PERV) that can infect human cells. In this study, to present a possible solution for this problem we tried to inhibit expression of PERVs using shRNAs(short hairpin RNA) at the level of RNA synthesis and virus release. The shRNA targeting the sequence of PERV A, B type was cloned into pSIREN-RetroQ vector under the control of polymerase-III U6-RNA gene promoter. Quantitative real-time PCR was performed to detect my alterations in mRNA production of PERV A, B targeted by the shRNA in each done. Depending on the target sequence of the shRNA, the transcription of PERV was decreased to as much as 4% and the number of progeny viruses was reduced to less than 1/200,000. Transgenic pigs producing such shRNAs may result in a highly reduced PERV expression in cells and organs, which is a prerequisite for safe xenotransplantations.