• International Journal of Industrial Entomology and Biomaterials
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• 제28권1호
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• pp.19-24
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• 2014

Silk has always been one of the most favored textile materials. Fully degummed silk fiber (i.e., silk fibers without sericin) shows better luster than raw silk fiber (with sericin); it is also softer. On the other hand, raw silk fiber feels cooler because of the presence of sericin, making it useful as a textile for the summer season. Recently, partially degummed silk has attracted researchers' attention because it provides better luster, feel, and dyeing properties. However, the partial degumming of silk is very difficult because it results in inhomogeneously degummed fiber. In the present study, silk yarns were degummed with surfactant aqueous solutions and the effects of each surfactant on the degumming ratio, crystallinity, and homogeneity of the degummed silk yarn were examined. The degumming ratio and crystallinity index of silk yarn varied depending on the type of surfactant. On the whole, anionic surfactants resulted in higher degumming ratios and better homogeneity than nonionic surfactants.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권2호
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• pp.171-174
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• 2007

Sericin beads were prepared from ethanol-precipitated sericin. The addition of ethanol into hot-water extracted sericin solution induced precipitation of sericin and thereby some sericin could be fractionated. The ethanol-precipitated sericin (EpSS) had narrower molecular weight distribution than original sericin. The EpSS had mainly random coil structure with small portion of ${\beta}-sheet$ structure. With the EpSS, spherical beads could be prepared at lower concentration than with original sericin due to higher viscosity. The EpSS beads had better compressive strength than the original sericin beads and had rubber-like property. Our results suggest that EpSS is more compatible in the polymeric field, since it has better mechanical strength than original sericin.

• International Journal of Industrial Entomology and Biomaterials
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• 제27권1호
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• pp.180-184
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• 2013

Recently, silk sericin has attracted the attention of researchers owing to its useful properties as a biomaterial including 1) good wound healing and cell activities, 2) fast gelation character, and 3) high water retention property. In the present study, silk sericin was prepared using different extraction times in hot water and the effect of extraction time on the rheological properties of sericin solutions and gels was examined. It was found that the production yield of sericin increased with extraction time. The shear viscosity of sericin solutions and gels decreased with increasing extraction time due to a decrease in sericin molecular weight. When the sericin solution transformed to a gel, the viscosity increased and the shear thinning behavior was more evident. In addition, the shear stress measurements indicated that the slip between the sericin samples and the measuring plate of the rheometer was increased by the gelation of sericin. The compression strength of sericin gel could be increased remarkably (by more than 100 fold) by preparation using the freezing and thawing method.

• 한국잠사곤충학회지
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• 제36권2호
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• pp.152-156
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• 1994

생사에 G.A.(glutaraldehyde)와 formalin을 혼합처리하는 방법으로 세리신정착을 실시한 다음 세리신 정착효과, 정착에 따른 백도의 변화, 물성 변화 등을 검토한 결과를 요약하면 다음과 같다. 1. G.A. 농도에 관계 없이 formalin 1% 용액 이상으로 정착하면 미정착사의 96%까지 백도가 향상된다. 2. Formalin G.A의 혼합처리에 의해 정련에 의한 백도 감소를 방지할 수 있었다. 3. Formalin 0.5% 용액 혼합처리로 완전한 세리신 정착을 얻을 수 있었다. 4. 세리신정착처리는 미정착사에 비해 강·신도의 증가를 가져왔다. 5. 정착사와 미정착사의 표면구조는 큰 차이가 없었다.

• 한국잠사곤충학회지
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• 제42권2호
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• pp.104-108
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• 2000

To hydrolyze insolule sericin the enzyme hydrolysis was used, and then obtained the results as given belows. When insoluble sericin was hydrolyzed by enzyme treatment, the solubility was best at pH 7, 60$\^{C}$ and was slightly increased both above 2 hours treatment and above 10% of enzyme concentration. As the results of electrophoresis, the distribution of molecular weight of sericin powder obtained by enzyme hydrolysis was very weak and showed in the wide range having no distinguishable band. Average degree of polymerzations (A.D.P.) of sericin hydrolyzed by enzyme were about 4.1∼6.3, average molecular weight were about 470∼730. The whiteness of the sericin powder obtained by enzyme hydrolysis was high and increased slightly with higher treatment concentration of enzyme. As the results of amino acid analysis, the amino acid analysis, the amino acid composition of the sericin powder from the enzyme treatment were similar to which located at near 230$\^{C}$ and 320$\^{C}$. The peak of near 230$\^{C}$ could not been found in the sericin powder obtained by enzyme hydrolysis.

• 한국잠사곤충학회지
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• 제43권2호
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• pp.109-115
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• 2001

실크 세리신 단백질을 추출정제하여 새로운 기능성 소재로 활용하기 위하여 세리신 추출법에 따른 세리신의 특성을 분석하고 약리효능과 피부친화성 소재로의 응용 가능성을 관능평가를 통하여 조사한 결과 다음과 같은 결론을 얻었다. 1. 실크 세리신 단백질을 효과적으로 추출하는 방법은 NaOH(0.02wt.%)로 처리하는 방법과 질소공기 하에서 식용효소인 Flavourzyme 3%로 처리하는 방법이 연감을 25wt.% 내외로 거의 100% 세리신을 회수하였다. 2. 추출된 세리신의 분자량 분포는 10,000-30,000 범위였으며 용해도는 90 wt.% 이상이었다. 또한 Actinase 등 단백질 분해 효소로 처리하여 분자량 2,700-4,200 의 저분자화 세리신을 얻을 수 있었으나 아미노산 조성은 고온고압 추출 세리신과 큰 차이가 없었다. 3.세리신의 항산화, 혈당강하 및 알콜대사에 미치는 영향을 살펴본 결과 유의성 있는 항산화 효과를 나타내지는 않았으나 세리신 투여시 sucrose와 maltose에 의하여 유발되는 혈당을 각각 62.6%, 41.5% 낮추는 효과를 나타내었다. 4. 피부친화성 소재로서 세리신의 활용가능성을 검토하기 위하여 중금속 함량을 측정한 결과 활성탄이나 wool filter를 이용함으로서 효과적으로 중금속을 제거할 수 있었으며, 세리신을 포함한 비누와 입욕제에 대한 관능평가 결과 세정력, 기포성, 세면후 피부보습성 등이 우수한 것으로 판정되어 실크 세리신 단백질은 피부친화성 미용 소재로 적용이 가능할 것으로 확인되었다.

• 한국잠사곤충학회지
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• 제55권2호
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• pp.44-53
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• 2019

Sericin has been removed in textile industry to improve the luster and hand of silk textile. Therefore, the sericin was considered as useless material. However, recently sericin has attracted researcher's attention since unique properties of sericin including high water retention, UV protection, and wound healing effect were reported. In spite of the useful properties of sericin as biomedical and cosmetic materials, its poor mechanical properties have restricted its industrial use in biomedical and cosmetic fields. To improve the mechanical properties, various sericins were prepared by different conditions, and the effects of the preparation condition on the structure and properties of sericin were examined. In this review paper, research trend in the structure and properties of sericin prepared with different conditions were intensively introduced.

• 한국잠사곤충학회지
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• 제44권1호
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• pp.37-41
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• 2002

실용성은 우수하나 위생성과 고급성이 매우 떨어지는 PET직물을 세리신을 이용하여 표면 개질함으로서 새로운 기능성을 부여하고자 하였다. Glutaraldehyde를 사용하여 세리신을 PET 직물에 가교시킬 경우 약 0.22%의 부착율을 보였으며, GA 수용액의 pH는 산으로 갈수록 좋고 세리신 수용액의 pH는 등전점에서 멀어질수록 반응이 쉽고 균일하게 일어났다. PDC 방법으로 세리신을 PET 직물의 부착시킬 경우 0.6%의 부착율을 보였는데 이는 가교제에 의한 경우보다 많이 부착이 되지만 직물에 균일하게 부착되지 않았다. 가교제 또는 PDC 방법을 통하여 PET 직물의 표면을 세리신으로 처리해도 수분율에 큰 영향을 주지 않았다. 즉 감량가공처리만으로도 흡수율이 크게 증가하였으며 이후 세리신을 처리하더라도 흡수율은 향상되지 않았으나 마찰대전성은 크게 향상되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제37권2호
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• pp.36-42
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• 2018

Recently, silk sericin has attracted attention because of its unique properties as a biomaterial, including its UV resistance, moisturizing effect on skin, and wound-healing effect. Therefore, the preparation of sericin in various forms such as gel, film, fiber, and sponge is studied for cosmetic and biomedical applications, and the effect of the preparation conditions on the structure and properties of sericin forms is examined to maximize its performance. In this study, silk sericin films were prepared under different preparation conditions and heat-treated at high temperatures ($100-250^{\circ}C$) to examine the effect of heat treatment on the film structure. The order of the crystallinity index of the untreated sericin film is as follows: F25 (sericin film cast from formic acid) > WE25 (ethanol treated sericin film cast from water at $250^{\circ}C$) > W25 (sericin film cast from water at $250^{\circ}C$) > W100 (sericin film cast from water at $100^{\circ}C$). As the heat-treatment temperature was increased, the color of the sericin films changed gradually from colorless to yellow, brown, and black depending on the temperature. The crystallinity of the sericin film changed after the heat treatment, depending on the preparation condition. Whereas a sericin film cast from formic acid (F25) started to lose its crystallinity at $200^{\circ}C$, thus undergoing the highest loss of crystallinity among the sericin films studied, the rest (W25, WE25, and W100) showed a decrease in crystallinity at $250^{\circ}C$, owing to the disruption of the ${\beta}$-sheet crystallites due to heat.

• International Journal of Industrial Entomology and Biomaterials
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• 제23권1호
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• pp.115-122
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• 2011

The effect of dietary feeding of silk fibroin/sericinmixtureson the antioxidative status and glucose metabolism in high fat-fed mice was investigated. The mice weregiven experimental diets for 6 weeks: normal control (NC),high fat (HF) andhigh fat supplemented with F100 (pure fibroin, HF-F100), F81 (81:19 fibroin-sericin, w/w, HF-F81) or F50 (50:50 fibroin-sericin, w/w, HF-F50). The silk protein-fed mice showed decreased lipid peroxidation, enhancedantioxidant enzymesactivities and lower blood glucose level relative to HF group. The HF-F50 animals exhibited significantly lower insulin level, higher glycogen concentration, enhanced hepatic glucokinaseactivity and reduced glucose-6-phosphate and phosphoenolpyruvatecarboxynaseactivities than the HF ones. The $in$ $vivo$ antioxidant activity and hypoglycemic action tended to increase with increased amount of sericin and decreased fibroin content in the diet. These findings demonstrate that silk protein, particularly sericin, may be beneficial in suppressing high fat diet-induced hyperglycemiaand oxidative stress.