• Title/Summary/Keyword: biomaterials

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Biomaterials-assisted spheroid engineering for regenerative therapy

  • Lee, Na-Hyun;Bayaraa, Oyunchimeg;Zechu, Zhou;Kim, Hye Sung
    • BMB Reports
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    • v.54 no.7
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    • pp.356-367
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    • 2021
  • Cell-based therapy is a promising approach in the field of regenerative medicine. As cells are formed into spheroids, their survival, functions, and engraftment in the transplanted site are significantly improved compared to single cell transplantation. To improve the therapeutic effect of cell spheroids even further, various biomaterials (e.g., nano- or microparticles, fibers, and hydrogels) have been developed for spheroid engineering. These biomaterials not only can control the overall spheroid formation (e.g., size, shape, aggregation speed, and degree of compaction), but also can regulate cell-to-cell and cell-to-matrix interactions in spheroids. Therefore, cell spheroids in synergy with biomaterials have recently emerged for cell-based regenerative therapy. Biomaterials-assisted spheroid engineering has been extensively studied for regeneration of bone or/and cartilage defects, critical limb ischemia, and myocardial infarction. Furthermore, it has been expanded to pancreas islets and hair follicle transplantation. This paper comprehensively reviews biomaterials-assisted spheroid engineering for regenerative therapy.

Mixed matrix membranes of poly(vinyl alcohol) loaded with phosphomolybdic heteropolyacid for the pervaporation separation of water-isopropanol mixtures (Water-IsopropanoI 혼합물의 투과증발 분리를 위한 poly(vinyl alcohol)-phosphomoIybdic heteropolyacid 혼합막)

  • Teli, Shivanand;Choi, Hyoung-Woo;Moon, Jung-Me;Park, Ji-Hye;Hong, Sung-Pyo;Tak, Tae-Moon
    • Proceedings of the Membrane Society of Korea Conference
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    • 2008.05a
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    • pp.51-57
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    • 2008
  • Mixed matrix membranes of poly(vinyl alcohol) (PVA), loaded with phosphomolybdic heteropolyacid (HPA) and crosslinked with glutaraldehyde have been prepared by the solution casting technique. Pervaporation (PV) experiments have been performed at $30^{\circ}C$ to separate water-isopropanol feed mixtures containing 10 to 40 wt.% of water. The membranes were characterized by DSC and DMTA to understand their thermal behavior and mechanical strength properties. At high content (i.e. 7 wt.% with respect to weight of PVA) of HPA, the mixed matrix membranes could extract water efficiently on the permeate side with a selectivity of 90,000 and a flux of 0.032 $kg/m^2h$ for 10 wt.% of water containing feed mixture (the lowest feed composition of water studied). Flux of the mixed matrix membranes decreased with increasing concentrations of HPA.

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Effect of Lyoprotectant on the Solubility and Structure of Silk Sericin

  • Kim, Moo-Kon;Kwak, Hyo-Won;Lee, Jeong-Yun;Yun, Hae-Sung;Kim, Min-Hwa;Lee, Ki-Hoon
    • International Journal of Industrial Entomology
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    • v.25 no.1
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    • pp.133-137
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    • 2012
  • To increase the solubility of lyophilized sericin, we added three types of lyoprotectant: sucrose, trehalose and dextran. The addition of lyoprotectant increased the solubility of lyophilized sericin especially when 1.0% of sucrose, 1.0% and 1.5% trehalose are added. The secondary structure of lyophilized sericin showed that the content of ${\beta}$-sheet or aggregated structure reduced in the presence of lyoprotectant. The morphology of lyophilized was also affected by the addition of lyoprotectant. Whereas flake structure was obtained in the case of pure sericin, a scattered and relatively small flake structure was formed in the presence of lyoprotectant. These finding shows that the presence of lyoprotectant prevents aggregation of sericin molecules and increases the solubility of lyophilized sericin.

Preparation and Drawing Property of Poly(vinyl alcohol) Film (폴리비닐알코올 필름의 제조 및 연신 특성)

  • Kim, Hun Min;Lee, Jungeon;Park, Jae Min;Park, Jae Hyeung;Choi, Jin Hyun;Yeum, Jeong Hyun
    • Textile Coloration and Finishing
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    • v.33 no.3
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    • pp.147-152
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    • 2021
  • Bulk polymerization was used to produce poly(vinyl acetate) with different molecular weights, which were then saponified to prepare poly(vinyl alcohol) (PVA) with different molecular weights. With Pn of 2,060 and 3,240, the optimum film formation concentrations of PVA were found 7.5wt.% and 6.5wt.%, respectively. The drawing characteristics of the PVA film prepared at the optimum film formation concentrations were experimented, as well as the thermal characteristics of the PVA film based on the drawing ratio were observed. When the drawing velocity was fixed, it was found that the drawing ratios of all samples decreased as the heat band gap increased, and the melting temperature of the PVA film slightly increased as the drawing ratio increased regardless of the Pn of PVA.

Development and Application of a Novel Mammalian Cell Culture System for the Biocompatibility and Toxicity of Polymer Films and Metal Plate Biomaterials (고분자필름과 금속막 의료소재에 대한 생체적합성 및 독성 평가를 위한 새로운 세포배양시스템의 개발 및 적용)

  • Kwak, Moon Hwa;Yun, Woo Bin;Kim, Ji Eun;Sung, Ji Eun;Lee, Hyun Ah;Seo, Eun Ji;Nam, Gug Il;Jung, Young Jin;Hwang, Dae Youn
    • Journal of Life Science
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    • v.26 no.6
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    • pp.633-639
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    • 2016
  • Biomaterials including polymer, metal, ceramic, and composite have been widely applied for medical uses as medical fibers, artificial blood vessels, artificial joints, implants, soft tissue, and plastic surgery materials owing to their physicochemical properties. However, the biocompatibility and toxicity for film- and plate-form biomaterials is difficult to measure in mammalian cells because there is no appropriate incubation system. To solve these problems, we developed a novel mammalian cell culture system consisting of a silicone ring, top panel, and bottom panel and we applied two polymer films (PF) and one metal plate (MP). This system was based on the principal of sandwiching a test sample between the top panel and the bottom panel. Following the assembly of the culture system, SK-MEL-2 cells were seeded onto Styela Clava Tunic (SCT)-PF, NaHCO3-added SCT (SCTN)-PF, and magnesium MP (MMP) and incubated at 37℃ for 24 hr and 48 hr. An MTT assay revealed that cell viability was maintained at a normal level in the SCT-PF culture group at 24 or 48 hr, although it rapidly decreased in the SCTN-PF culture group at 48 hr. Furthermore, the cell viability in the MMP culture group was very similar to that of the control group after incubation for 24 hr and 48 hr. Together, these results suggest the sandwich-type mammalian culture system developed here has the potential for the evaluation of the biocompatibility and toxicity of cells against PF- and MP-form biomaterials.

Inhibition of endoplasmic reticulum stress in high-fat-diet-induced obese C57BL/6 mice: Efficacy of a novel extract from mulberry (Morus alba) leaves fermented with Cordyceps militaris

  • Lee, Mi Rim;Bae, Su Ji;Kim, Ji Eun;Song, Bo Ram;Choi, Jun Young;Park, Jin Ju;Park, Ji Won;Kang, Mi Ju;Choi, Hyeon Jun;Choi, Young Whan;Kim, Kyung Mi;Hwang, Dae Youn
    • Laboraroty Animal Research
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    • v.34 no.4
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    • pp.288-294
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    • 2018
  • A few clues about correlation between endoplasmic reticulum (ER) stress and mulberry (Morus alba) leaves were investigated in only the experimental autoimmune myocarditis and streptozotocin-induced diabetes. To investigate whether a novel extract of mulberry leaves fermented with Cordyceps militaris (EMfC) could suppress ER in fatty liver, alterations in the key parameters for ER stress response were measured in high fat diet (HFD)-induced obese C57L/6 mice treated with EMfC for 12 weeks. The area of adipocytes in the liver section were significantly decreased in the HFD+EMfC treated group as compared to the HFD+Vehicle treated group, while their level was higher in HFD+Vehicle treated group than No treated group. The level of the eukaryotic initiation factor 2 alpha ($eIF2{\alpha}$) and inositol-requiring enzyme 1 beta ($IRE1{\alpha}$) phosphorylation and CCAAT-enhancer-binding protein homologous protein (CHOP) expression were remarkably enhanced in the HFD+Vehicle treated group. However, their levels were restored in the HFD+EMfC treated group, although some differences were detected in the decrease rate. Similar recovery was observed on the ER stress-induced apoptosis. The level of Caspase-3, Bcl-2 and Bax were decreased in the HFD+EMfC and HFD+orlistat (OT) treated group compared to the HFD+Vehicle treated group. The results of the present study therefore provide first evidence that EMfC with the anti-obesity effects can be suppressed ER stress and ER stress-induced apoptosis in the hepatic steatosis of HFD-induced obesity model.

Effect of Vitamin D3 on Biosynthesis of Estrogen in Porcine Granulosa Cells via Modulation of Steroidogenic Enzymes

  • Hong, So-Hye;Lee, Jae-Eon;An, Sung-Min;Shin, Ye Young;Hwang, Dae Youn;Yang, Seung Yun;Cho, Seong-Keun;An, Beum-Soo
    • Toxicological Research
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    • v.33 no.1
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    • pp.49-54
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    • 2017
  • Vitamin D3 is a fat-soluble secosteroid responsible for enhancing intestinal absorption of calcium, iron, and other materials. Vitamin D3 deficiency, therefore, can cause health problems such as metabolic diseases, and bone disorder. Female sex hormones including estrogen and progesterone are biosynthesized mainly in the granulosa cells of ovary. In this study, we isolated granulosa cells from porcine ovary and cultured for the experiments. In order to examine the effect of vitamin D3 on the ovarian granulosa cells, the mRNA and protein levels of genes were analyzed by real-time PCR and Western blot assay. The production of estrogen from the granulosa cells was also measured by the ELISA assay. Genes associated with follicle growth were not significantly altered by vitamin D3. However, it increases expression of genes involved in the estrogen-biosynthesis. Further, estrogen concentrations in porcine granulosa cell-cultured media increased in response to vitamin D3. These results showed that vitamin D3 is a powerful regulator of sex steroid hormone production in porcine granulosa cells, suggesting that vitamin D deficiency may result in inappropriate sexual development of industrial animals and eventually economic loss.

Effect of Different Delignification Degrees of Korean White Pine Wood on Fibrillation Efficiency and Tensile Properties of Nanopaper (잣나무의 탈리그닌 정도가 습식 해섬처리 효율 및 나노종이 인장 특성에 미치는 영향)

  • Park, Chan-Woo;Lee, Seo-Ho;Han, Song-Yi;Kim, Bo-Yeon;Jang, Jae-Hyuk;Kim, Nam-Hun;Lee, Seung-Hwan
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.1
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    • pp.17-24
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    • 2015
  • In this study, the effect of delignification degree of Korean white pine wood on fibrillation efficiency by wet disk-milling (WDM) and the properties of thus-obtained microfibrillated cellulose (MFC) were investigated. The effect on the tensile properties of nanopaper was also investigated. The delignification degree was adjusted by repeating 'Wise' method using sodium chlorite and acetic acid. The increase in delignification degree improved fibrillation efficiency, showing the smaller nanofiber dimension at the shorter WDM time. The filtration time of MFC water suspension was increased by the increase of WDM cycles. Tensile strength and elastic modulus of the nanopaper were increased by increasing delignification degree and disk-milling cycles.

Preparation of PVA/Wheat Gliadin Blend Fiber Using an Organic Solvent (유기용매를 이용한 PVA/밀 글리아딘 블렌드 섬유의 제조 및 특성분석)

  • Kwak, Hyo-Won;Kim, Moo-Kon;Oh, Han-Jin;Lee, Jeong-Yun;Yun, Hae-Sung;Lee, Jong-Hwan;Lee, Ki-Hoon;Shin, Bong-Seob
    • Textile Science and Engineering
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    • v.48 no.4
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    • pp.252-257
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    • 2011
  • In this study PVA/wheat gliadin blend fiber was prepared by wet spinning using DMSO as a solvent and acetone/methanol as a coagulant. The PVA content should be greater than 40% to demonstrate successful drawing. The maximum draw ratios of the blend fiber were 6, 7.5 and 8, when the PVA content was 40, 60 and 80%, respectively. The surface of the blend fiber became rougher and macrovoids were found when the content of gliadin was increased, this was due to the skin-core effect. The ultimate stress, breaking strain and modulus of the blend fiber were increased with an increase of the PVA content. The crystallinity of the blend fiber decreased when the gliadin content increased, the secondary structure of the gliadin however did not change in the presence of PVA. In order to increase the water stability of the blend fiber, further cross-linking was performed which also improved the mechanical properties of the blend fiber.

Correlations between the Growth Period and Fresh Weight of Seed Sprouts and Pixel Counts of Leaf Area

  • Son, Daesik;Park, Soo Hyun;Chung, Soo;Jeong, Eun Seong;Park, Seongmin;Yang, Myongkyoon;Hwang, Hyun-Seung;Cho, Seong In
    • Journal of Biosystems Engineering
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    • v.39 no.4
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    • pp.318-323
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    • 2014
  • Purpose: This study was carried out to predict the growth period and fresh weight of sprouts grown in a cultivator designed to grow sprouts under optimal conditions. Methods: The temperature, light intensity, and amount of irrigation were controlled, and images of seed sprouts were acquired to predict the days of growth and weight from pixel counts of leaf area. Broccoli, clover, and radish sprouts were selected, and each sprout was cultivated in a 90-mm-diameter Petri dish under the same cultivating conditions. An image of each sprout was taken every 24 hours from the 4th day, and the whole cultivating period was 6 days, including 3 days in the dark. Images were processed by histogram inspection, binary images, image erosion, image dilation, and the overlay image process. The RGB range and ratio of leaves were adjusted to calculate the pixel counts for leaf area. Results: The correlation coefficients between the pixel count of leaf area and the growth period of sprouts were 0.91, 0.98, and 0.97 for broccoli, clover, and radish, respectively. Further, the correlation coefficients between the pixel count of leaf area and fresh weight were 0.90 for broccoli, 0.87 for clover, and 0.95 for radish. Conclusions: On the basis of these results, we suggest that the simple image acquisition system and processing algorithm can feasibly estimate the growth period and fresh weight of seed sprouts.