• Textile Coloration and Finishing
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• v.21 no.6
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• pp.56-63
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• 2009

In this study we have evaluated the separation characteristics and concentration of sericin using tubular type ultrafiltration membrane in silk degumming solution that extracted from electrolytic reduction water process. Ultrafiltration membranes have used in sericin separation performance and the separation characteristics of membrane satisfied typical Hagen-Poiseuille equation. It had the increase of flux according to the increase of feed pressure and temperature in occasion of pure water flux. And also the flux and solute rejection had about $25{\sim}60{\ell}/m^2{\cdot}h$ and more than 95% in sericin feed solution with concentration 1.00~1.89% at feed pressure force of $3{\sim}8kgf/cm^2$ respectively. In addition, the separation performance of tubular type ultrafiltration membrane for silk degumming solution was very steady-state with long experiment time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.1004-1009
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• 2001

Acid hydrolysates of cocoon was gained by acid hydrolysis of 2 N HCl, 11$0^{\circ}C$, 48 hours, neutralization and desalting from the cocoon. The amino acid compositions of acid hydrolysates of cocoon were glycine 43.25%, alanine 34.39%, serine 10.05% and valine 2.44%. The contents of essential amino acid was 10.05%. Food efficiency ratio of acid hydrolysates of cocoon group was equal to the reference protein, casein. Liver weight, GOT, GPT activity, serum albumin and serum total protein level of rats were not significantly different among the experimental groups. Therefore, the protein acid hydrolysates of cocoon is not of high quality. When the rat fed with high cholesterol, high lipid, and high sucrose diet was administered with 5% acid hydrolysates of cocoon, its plasma lipids concentration of acid hydrolysates of cocoon was favorably affected: its triglyceride was decreased, and the level of phospholipid and HDL cholesterol were increased. There was also an unfavorable effect: the levels of LDL cholesterol and total cholesterol went up. Therefore, the acid hydrolysates of cocoon is not a good protein food source, but is can be used a cosmetic, medical, or packing material. Further research will reveal how it will affect or improve plasma lipid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.715-722
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• 2003

This study is to investigate effects of green tea and capsulated components mixture on body fat and serum lipid composition and fat distribution in college women students in terms of supplemented periods. During 3 months of this research, 34 college women students (average age 20.3 yr) were selected as subjects. Nutrient intake was investigated by questionnaire and 24-hr recall method. Anthropolatric assessments of the subjects were investigated by SBIA method (Segmental Bioimpedance Assay, Inbody 3.0). The results were as follows: mean body height was 162.5cm and mean body weight and mean BMI (Body Mass Index, kg/$m^2$) were 57.9kg and 21.9, respectively. Status of carbohydrate intake decreased significantly (p<0.05) and dietary fiber intake increased significantly (p<0.001) after supplementation. WHR (waist-hip ratio) decreased significantly (p<0.05) and body fat and percent body fat decreased significantly after supplementation (p<0.05). Total cholesterol and triglyceride decreased significantly after supplementation (p<0.001). Above results of this study show that green tea, silk peptide and dietary fiber supplementation-added routine diet improves body fat distribution, total cholesterol, triglyceride. Especially, declination of abdominal fat and WHR was notable, since that means diminution of risk factors for obesity and chronic degenerative diseases.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.123-129
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• 2003

This study is to investigate consequent nutrient intake status, Influences of body mass index (BMI) and serum lipid composition, and fat distribution on the cocoon hydrolysate, green tea leaves and dietary fiber supplementation. During 2 months of this research (April to May, 2002), 47 women aged 20 yr-30 yr (average age 26.2 yr) were selected as subjects. Nutrient intake was investigated by questionnaire and 24-hr recall method. Antropometric assessments of the subjects were investigated by SBIA method (Segmental bioimpedance assay, Inbody 3.0). The results were as follows: mean body weight was 60.7 kg, mean body height 161.7 cm and mean BMI 23.4. Status of energy intakes significantly decreased (p<0.01) and dietary fiber intakes significantly increased (p<0.001) after supplementation. BMI and WHR (waist-hip ratio) significantly decreased (p<0.01) and body fat significantly decreased after supplementation (p<0.001). Total cholesterol and LDL-cholesterol significantly decreased after supplementation (p<0.05). HDL-cholesterol was negatively correlated with BMI and WHR (p<0.01). LDL/HDL ratio was positively correlated with BMI (p<0.01) and WHR (p<0.05). Above results of this study show that low-molecule peptide, green tea leaves and dietary fiber supplementation-added routine diet improves lessening body fat distribution, total cholesterol, LDL-cholesterol. Especially, decrease of abdominal fat and WHR were notable. That meant decrease of risk factors.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.132-139
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• 2010

Sericin pulverization process was applied by freezing-thawing of sericin protein concentration solution and physicochemical properties of sericin/chitosan blended films were investigated. In sericin pulverization process by freezing-thawing method, the refrigeration storage at $4^{\circ}C$ maximized gelling between sericin molecules, which increased 10% of recovery ratio from sericin concentration solution that using ultrafiltration procedure. In physicochemical properties of sericin/chitosan blended films, the maximum load of chitosan (6.7kgf) had higher than that of sericin (1.2kgf), and the elongation of sericin and chitosan had 96% and 34%, respectively. Also FT-IR analysis of sericin/chitosan blended films showed that both sericin and chitosan films had amide I peak (N-H bond) in $1,521cm^{-1}$ and amide II peak (C=O bond) in $1,630cm^{-1}$. In addition, it could confirm compatibility between both materials as indicated by the decrease in the amide I peak's absorption value as chitosan content increases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.250-254
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• 2010

Introduction: This study evaluated the bone regenerative effect of silk fibroin mixed with platelet-rich fibrin (PRF) of a bone defect in rabbits. Materials and Methods: Ten New Zealand white rabbits were used for this study and bilateral round shaped defects were formed in the parietal bone (diameter: 8.0 mm). The silk fibroin mixed with PRF was grafted into the right parietal bone (experimental group). The left side (control group) was grafted only PRF. The animals were sacrificed at 4 weeks and 8 weeks. A micro-computerized tomography (${\mu}$CT) of each specimen was taken. Subsequently, the specimens were decalcified and stained for histological analysis. Results: The average value of plane film analysis was higher in the experimental group than in the control group at 4 weeks and 8weeks after surgery. However, the difference was not statistically significant.(P>0.05) The tissue mineral density (TMD) in the experimental group at 4 weeks after surgery was significantly higher than the control group.(P<0.05) Conclusion: Silk fibroin can be used as a scaffold of PRF for rabbit calvarial defect repair.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.5
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• pp.680-686
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• 2010

Silk sericin protein was hydrolyzed by seven proteolytic enzymes in order to examine the effectiveness of the hydrolysates in binding calcium. The amino acid nitrogen content of hydrolysates from Flavourzyme was higher than that for other enzymes, and its calcium binding capacity showed a dose-dependent increase. We examined the effects of calcium binding peptide from sericin hydolysates on the bioavailability of Ca-deficient rats. Three-week-old male rats were fed an Ca-deficient diet for three weeks. Rats were divided into four groups (DD: non-treated group on calcium deficient diet; DD+MC: milk-calcium treated group; DD+OC: organic calcium made using sericin hydolysates; and DD+IC: inorganic calcium ($CaCl_2$). After oral administration of calcium supplements for one week, the calcium content of the serum and liver were significantly higher in DD+OC ($101.7{\mu}g$/mL and $49.3{\mu}g$/mL) and DD+MC ($83.6{\mu}g$/mL and $42.8{\mu}g$/mL) than DD ($86.3{\mu}g$/mL and $43.4{\mu}g$/mL). The alkaline phosphatase (ALP) content in the treated groups was significantly lower than DD, but no significant difference among groups was shown. Aspartate aminotransferase (AST) levels did not show any significant difference between groups. Alanine aminotransferase (ALT) levels were significantly reduced compared to the DD group. In conclusion, binding calcium to peptides from sericin hydrolysates seems to improve its bioavailability, and to hasten the cure of calcium deficiency in experimental rats.

• Journal of Life Science
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• v.20 no.8
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• pp.1249-1253
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• 2010

Sericin is a type of high molecular weight water-soluble glycoprotein surrounding fibroin (silk protein) that has been used as a cell culture supplement and accelerates cell proliferation in various serum-free media. The purpose of this study was to investigate the enhancing effect of thyroglobulin (Tg) secretion by sericin in thyrocytes, FRTL-5 cells. While Tg-mRNA expression was not enhanced, a secreted form of Tg was obviously increased by sericin. In this status, expression of both endoplasmic reticulum (ER) molecular chaperones (Bip & calreticulin) and ER membrane proteins (IRE1, PERK & ATF6) was enhanced. The proximal step of IRE1, XBP1 mRNA splicing was slightly detected however, the proximal step of PERK, phosphorylation of $eIF2{\alpha}$, was changeless. In addition, sericin enhanced cell viability by the MTT assay. The above results showing the ability of sericin to promote protein production demonstrated its potential usefulness as a new biomaterial.

• Applied Chemistry for Engineering
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• v.31 no.1
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• pp.13-18
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• 2020

Iron oxide nanoparticles were microencapsulated using fibroin, a protein polymer of silk fiber, for theragnostic applications. The content of iron oxide was determined to be 4.28% by thermogravimetric analysis and 5.11% by magnetometer. A suspension of murine fibroblast 3T3 cells grown in medium supplemented with iron oxide-microcapsules turned clear in response to the magnetic force and the cells aggregated to the magnet direction. Neodymium magnets placed on the top of the culture dish, and attracted cells to the center of the culture surface. The cells collected on the culture surface aggregated to form a rough spheroid of 2 mm in a diameter after 72 h. In the outer layer of the cell aggregate, cells were relatively large and gathered together to form a dense tissue, but the central part was observed to undergo cell death due to the mass transfer restriction. In the outer layer, iron oxide-microcapsules were lined up like chains in the direction of magnetic force. Using microCT, it was demonstrated that the iron oxides inside the cell aggregate were not evenly distributed but biased to the magnetic direction.

• Journal of Nutrition and Health
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• v.45 no.2
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• pp.113-120
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• 2012

In our previous studies, dietary supplements of silk protein, sericin, and fibroin, were beneficial for improving epidermal levels of ceramides, which are the major lipids for maintaining the epidermal barrier. In this study, we investigated the dietary effects of silk protein on epidermal levels of free sphingoid bases and their phosphates such as $C_{18}$ sphingosine (So), $C_{18}$ sphinganine (Sa), $C_{18}$ sphingosine-1-phosphate (S1P), and $C_{18}$ sphinganine-1-phosphate (Sa1P), which are either synthetic substrate or degradative metabolites of ceramides. Forty-five male NC/Nga mice, an animal model of atopic dermatitis (AD), were divided into three groups: group CA was an atopic control and fed a control diet, group S was fed a 1% sericin diet, and group F was fed a 1% fibroin diet. Fifteen male BALB/c mice served as group C (control group) and were fed the control diet. All mice were fed with diets and water $ad$ $libitum$ for 10 weeks. Sa in group CA was lower than that in group C, but So in group CA was similar to that in group C. So and Sa were higher in groups S and F than those in group CA; So level was even higher than that in group C, and Sa level was similar to that of group C. The So/Sa ratio in group CA, which is reported to increase in AD, was significantly higher than that of group C. The So/Sa ratio was lower in groups S and F than that in group CA, and decreased further in group F. However, S1P and Sa1P in groups S and F were similar to those in group CA. Taken together, we demonstrated that silk protein, sericin and fibroin dietary supplements, increased So and Sa levels, and decreased the So/Sa ratio.