• Title/Summary/Keyword: tissue-engineering

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In vivo Bone Regeneration by Using Chitosan Scaffolds with KUSA-A1 Oesteoblast Cells (KUSA-A1 골조세포 함유 키토산 지지체를 이용한 생체내 골재생)

  • Lim, Hyun-Ju;Oh, Eun-Jung;Choi, Jin-Hyun;Chung, Ho-Yun;Ghim, Han-Do
    • Polymer(Korea)
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    • v.36 no.4
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    • pp.401-406
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    • 2012
  • For bone regeneration from KUSA-A1 oesteoblast cells (KUSA), chitosan (CS) scaffolds possessing different surface properties, sponge-type (CSS) and nonwoven-type (CSNW), were manufactured. Surface area and pore size of CSNW were larger than those of CSS. On the other hand, the pore volume of CSNW was smaller than that of CSS. Cell attachment evaluation showed CSNW was more adequate then CSS, and this was attributed to the large surface area. For in vivo investigation, KUSA were seeded into CS scaffolds in wells followed by a week of cell culture. Obtained CS scaffolds with KUSA were implanted on the subcutaneous tissue of BALB/C nude mice. After surgery, implanted scaffolds were harvested and assayed by immunological staining. Network stability of CSS was better than that of CSNW, even if CSS scaffolds were destroyed between 4 and 6 weeks. Calcification was observed after 4 and 8 weeks for CSNW and CSS, respectively.

Geospatial Assessment of Frost and Freeze Risk in 'Changhowon Hwangdo' Peach (Prunus persica) Trees as Affected by the Projected Winter Warming in South Korea: II. Freezing Risk Index Based on Dormancy Depth as a Proxy for Physiological Tolerance to Freezing Temperature (겨울기온 상승에 따른 복숭아 나무 '장호원황도' 품종의 결과지에 대한 동상해위험 공간분석: II. 휴면심도로 표현한 생리적 내동성에 근거한 동해위험지수)

  • Kim, Jin-Hee;Kim, Soo-Ock;Chung, U-Ran;Yun, Jin-I.;Hwang, Kyu-Hong;Kim, Jung-Bae;Yoon, Ik-Koo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.11 no.4
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    • pp.213-220
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    • 2009
  • In order to predict the risk of freeze injury for 'Changhowon Hwangdo' peach trees, we used the dormancy depth (i.e., the daily chill unit accumulation during the overwintering period) as a proxy for the short-term, physiological tolerance to freezing temperatures. A Chill-days model was employed and its parameters such as base temperature and chilling requirement were optimized for peach trees based on the 12 observational experiments during the 2008-2009 winter. The model predicted the flowering dates much closer to the observations than other models without considering dormancy depth, showing the strength of employing dormancy depth into consideration. To derive empirical equations for calculating the probabilistic freeze risk, the dormancy depth was then combined with the browning ratio and the budburst ratio of frozen peach fruit branches. Given the exact date and the predicted minimum temperature, the equations calculate the probability of freeze damages such as a failure in budburst or tissue browning. This method of employing dormancy depth in addition to freezing temperature would be useful in locating in advance the risky areas of freezing injury for peach trees production under the projected climate change.

Development and application of non-invasive drug delivery systems utilizing pulse power, and its application to mouse models (펄스파워를 적용한 비침습 약물 전달기 개발 및 마우스 모델로의 적용)

  • Hwi-Chan Ham;Kyu-Sik Kim;Ji-Hwan Lee;Hyung-Jin Choi;Do-Nyun Kim;Jai-Ick Yoh
    • Journal of IKEEE
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    • v.28 no.1
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    • pp.97-103
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    • 2024
  • Some drugs can offer far better medical effectiveness as it is injected through the intradermal layer of the skin, known as a needle-free injection. However, conventional needle-free devices might deliver a relatively large amount of drug in a just single spot of skin, splitting open the tissue layer structure, which might cause bruising and bleeding. By injecting the small volume with a fast repetition rate in a large surface area of skin, the patient may get much fewer injuries and pain. To achieve that specification, the driving force must be instantaneous and short-pulsed. Such a form of an injection device has been developed but the efficacy of those devices has been rarely examined. Therefore, this study developed the laser-induced microjet device that ejects microjet whose speed is ~310 m/s, during the 400~800 ㎲ of pulse time. The device can eject ~1 µL of the drug at the rate at which each shot repeated 10 shots per second. Using this specification, we evaluated the efficacy of drug injection onto mouse models. After injecting the insulin solution into the mouse model, the blood insulin level is detected, resulting in 20 % of blood insulin level with the ordinary needle syringe injection method.

Dependency of Generator Performance on T1 and T2 weights of the Input MR Images in developing a CycleGan based CT image generator from MR images (CycleGan 딥러닝기반 인공CT영상 생성성능에 대한 입력 MR영상의 T1 및 T2 가중방식의 영향)

  • Samuel Lee;Jonghun Jeong;Jinyoung Kim;Yeon Soo Lee
    • Journal of the Korean Society of Radiology
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    • v.18 no.1
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    • pp.37-44
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    • 2024
  • Even though MR can reveal excellent soft-tissue contrast and functional information, CT is also required for electron density information for accurate dose calculation in Radiotherapy. For the fusion of MRI and CT images in RT treatment planning workflow, patients are normally scanned on both MRI and CT imaging modalities. Recently deep-learning-based generations of CT images from MR images became possible owing to machine learning technology. This eliminated CT scanning work. This study implemented a CycleGan deep-learning-based CT image generation from MR images. Three CT generators whose learning is based on T1- , T2- , or T1-&T2-weighted MR images were created, respectively. We found that the T1-weighted MR image-based generator can generate better than other CT generators when T1-weighted MR images are input. In contrast, a T2-weighted MR image-based generator can generate better than other CT generators do when T2-weighted MR images are input. The results say that the CT generator from MR images is just outside the practical clinics and the specific weight MR image-based machine-learning generator can generate better CT images than other sequence MR image-based generators do.

Anti-inflammatory effect of Althaea rosea L. Callus extract by applying biorenovation (생물전환 기법을 적용한 접시꽃 callus 추출물의 항염증 활성)

  • Yeon-Su Koo;Tae-Jin Park;Jung-Hwan Kim;Seung-Young Kim
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.39-45
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    • 2023
  • Biorenovation is a biotransformation method that converts the structure of chemical compounds and natural product through biocatalytic metabolism of microorganism and could enhance biological effectiveness and mitigate cytotoxicity compared to its substrates. Althaea rosea L. has been used as oriental medicine and is known for physiological efficacies such as antiurolithiatic, anti-inflammatory, and anti-cancer activities. A. rosea L. callus, the plant tissue grown to protect its wound, has been reported to have antioxidant and whitening effects. However, mechanisms of its other activity such as inflammation have not yet been investigated. In this study, we extracted A. rosea L. callus (AR) and produced biorenovated AR (ARBR), and then analyzed anti-inflammatory effect in Lipopolysaccharide-induced RAW 264.7 macrophage at 50, 100, 200 ㎍/mL of ARBR. As a result of inhibition test of nitric oxide production, it was found that ARBR was superior to AR without apparent toxicity. Furthermore, ARBR significantly inhibited production of prostaglandin E2, inducible nitric oxide synthase, cyclooxygenase-2 and pro-inflammatory cytokines including Tumor necrosis factor-α, Interleukin-6, Interleukin-1β in a concentration-dependent manner. In conclusion, we suggest that ARBR could regulate the excessive inflammatory response to an appropriate level and be a promising material for functional cosmetics and pharmaceuticals.

Zinc-chelated Vitamin C Stimulates Adipogenesis of 3T3-L1 Cells

  • Ghosh, Chiranjit;Yang, Seung Hak;Kim, Jong Geun;Jeon, Tae-Il;Yoon, Byung Hyun;Lee, Jai Young;Lee, Eun Young;Choi, Seok Geun;Hwang, Seong Gu
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.8
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    • pp.1189-1196
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    • 2013
  • Adipose tissue development and function play a critical role in the regulation of energy balance, lipid metabolism, and the pathophysiology of metabolic syndromes. Although the effect of zinc ascorbate supplementation in diabetes or glycemic control is known in humans, the underlying mechanism is not well described. Here, we investigated the effect of a zinc-chelated vitamin C (ZnC) compound on the adipogenic differentiation of 3T3-L1 preadipocytes. Treatment with ZnC for 8 d significantly promoted adipogenesis, which was characterized by increased glycerol-3-phosphate dehydrogenase activity and intracellular lipid accumulation in 3T3-L1 cells. Meanwhile, ZnC induced a pronounced up-regulation of the expression of glucose transporter type 4 (GLUT4) and the adipocyte-specific gene adipocyte protein 2 (aP2). Analysis of mRNA and protein levels further showed that ZnC increased the sequential expression of peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein alpha (C/$EBP{\alpha}$), the key transcription factors of adipogenesis. These results indicate that ZnC could promote adipogenesis through $PPAR{\gamma}$ and C/$EBP{\alpha}$, which act synergistically for the expression of aP2 and GLUT4, leading to the generation of insulin-responsive adipocytes and can thereby be useful as a novel therapeutic agent for the management of diabetes and related metabolic disorders.

Regeneration of Intervertebral Disc Using Gellan Sponge Loading PLGA Microspheres (PLGA 미립구가 함유된 젤란검 스폰지를 이용한 추간판 조직 재생)

  • Park, Hyunwoo;Kim, Hye Yun;Kwon, Soon Yong;Khang, Gilson;Kim, Yong-Sik
    • Polymer(Korea)
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    • v.39 no.1
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    • pp.144-150
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    • 2015
  • Gellan gum as a natural polysaccharide has good heat resistance, acid resistance and enzymes resistance. However, one of the drawbacks of gellan gum might be the lower mechanical strength. In this work, gellan gum scaffolds were mixed with poly(lactic-co-glycolic acid) (PLGA) microsphere in order to improve mechanical properties. The gellan gum scaffolds with various contents of PLGA microsphere were prepared for the regeneration of disc tissues. To evaluate the mechanical strength of hybrid structure of gellan gum and PLGA microsphere, compression strength of the fabricated scaffolds was measured. MTT analysis, SEM observation, histological evaluation and RT-PCR were performed to confirm the effect on the cell growth and extracellular matrix secretion. As a result, it showed the best cell proliferation and extracellular matrix secretion in gellan gum sponge containing 50% PLGA microspheres. In conclusion, this study confirmed that the hybrid structure of gellan gum and PLGA microspheres was found suitable in regeneration of the intervertebral disc.

Expression of β-arrestin 1 in Gastric Cardiac Adenocarcinoma and its Relation with Progression

  • Wang, Li-Guang;Su, Ben-Hua;Du, Jia-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5671-5675
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    • 2012
  • Objective: Arrestins act as mediators of G protein-coupled receptor (GPCR) desensitization and trafficking, also actin as a scaffold for many intracellular signaling network. The role that ${\beta}$-arrestin 1 plays in gastric cardiac adenocarcinoma (GCA) and its clinicopathologic significance are untouched. Methods: Fifty patients with gastric cardiac adenocarcinoma were retrospectively enrolled and ${\beta}$-arrestin 1 was detected using immunohistochemistry in tissue samples. Results: Nuclear expression of ${\beta}$-arrestin 1 was observed in 78% of GCA samples (39/50) and cytoplasmic expression in 70% (35/50). ${\beta}$-arrestin 1 could be found in both nucleus and cytoplasm of 54% GCA (27/50) or in either of them in 94% (47/50). ${\beta}$-arrestin 1 protein positivity in well/moderately differentiated carcinomas was significantly higher than that in poorly differentiated carcinomas (P=0.005). We found increased expression of ${\beta}$-arrestin 1 in cytoplasm was correlated with lymph nodal metastasis (P=0.002) and pathological lymph nodal staging (P=0.030). We also found ${\beta}$-arrestin 1 to be over-expressed in glandular epithelia cells of mucinous adenocarcinoma, a tumour type associated with an adverse outcome of gastric cardiac adenocarcinoma (P=0.022). Conclusion: ${\beta}$-arrestin 1 is over-expressed in the nucleus and/or cytoplasm of gastric cardiac adenocarcinoma. However, ${\beta}$-arrestin 1 has no relationship with the prognosis of gastric cardiac adenocarcinoma (P>0.05). Our data imply that ${\beta}$-arrestin 1 in cytoplasm may be involved in differentiation and metastasis of gastric cardiac adenocarcinoma.

The Herbal Composition Gangjihwan from Ephedra intermedia, Lithospermum erythrorhizon and Rheum palmatum Ameliorates Hepatic Inflammation and Fibrosis in Obese C57BL/6J Mice and HepG2 Cells

  • Yoon, Michung
    • Biomedical Science Letters
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    • v.23 no.2
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    • pp.144-153
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    • 2017
  • It was demonstrated that Gangjihwan (DF), which is the herbal composition composed of Ephedra intermedia, Lithospermum erythrorhizon, and Rheum palmatum, inhibits obesity and hepatic steatosis in high fat diet (HFD)-fed obese mice. The aim of this study was to determine the effects of DF on visceral obesity, hepatic inflammation and fibrosis and the mechanism of actions involved in this process using in vivo and in vitro approaches. DF was extracted with water (DF-FW), 30% grain alcohol (DF-GA30), and 70% grain alcohol (DF-GA70). Administration of DF to HFD-fed control mice decreased visceral tissue mass and visceral adipocyte size without adverse effects. Visceral fat mass was decreased by DF-GA30 and DF-GA70, and visceral adipocyte size by all three DF extracts compared with obese control mice. Histological analysis revealed that three kinds of DF extracts reduced toluidine blue-stained mast cells and collagen accumulation in the liver, the extents of which were most eminent in DF-GA70-treated mice. DF-GA70 decreased the mRNA levels of the inflammation ($TNF{\alpha}$ and VCAM-1), fibrosis (${\alpha}-SMA$), and apoptosis (caspase 3) genes, but increasing the anti-apoptosis gene (Bcl-2) mRNA levels in the liver of obese control mice. Consistent with the in vivo data, GA-70 also altered the expression of inflammation genes ($TNF{\alpha}$ and MCP-1) in HepG2 cells. These results indicate that DF not only inhibits visceral obesity, but also ameliorates visceral obesity-induced hepatic inflammation and fibrosis and that this process may be mediated by regulating the hepatic expression of inflammatory and fibrogenic genes.

Ameliorative Effects of Combinative Injection of Ginko biloba Leaves Extract and Vitamin C on Ischemia/Reperfusion Liver Damages Model

  • Xie, Guang-Hua;Choi, Sun Eun;Mun, Myung-Jae;Jeong, Jae-Hun;Park, Kwang-Hyun
    • Korean Journal of Plant Resources
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    • v.31 no.3
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    • pp.268-273
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    • 2018
  • Hepatic ischemia-reperfusion injury (HIRI) is linked with high mortality rate. Several agents have been developed so far to reduce the risk of HIRI. In this study, we investigated the effects of combined treatment of Ginko biloba leaves extract and vitamin C (GLEVC) on hepatic ischemia-reperfusion injury. To explore the protective effects of GLEVC on HIRI rats model were tested. After the development of HIRI by using clamping method rats were then randomly divided into four groups. Different doses of GLEVC were administered in HIRI rat model. The level of ALT, AST, SOD and MDA content in serum were detected in HIRI groups. Moreover, the activity of SOD, content of MDA, and GSH in hepatic tissue were also examined. Bcl-2 and Bax protein expression were detected by immunohistochemical staining method. Compared with sham group, GLEVC has the protective effect on the HIRI-induced model. Level of ALT, AST, and MDA in blood were significantly lower in GLEVC group compared with HIRI-induced group. Moreover, SOD activity and GSH were increased in GLEVC group whereas MDA content was reduced by GLEVC treatment. Furthermore, HIRI-induced Bax protein was reduced upon GLEVC treatment, whereas Bcl-2 protein expression was enhanced. These results demonstrate that GLEVC treatment may provide potential ameliorative therapy by reducing damaged signaling mechanism in hepatic ischemia/reperfusion injury model.