• Journal of Nutrition and Health
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• 제30권7호
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• pp.751-769
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• 1997

This study was performed to investigate the effect of chitosan and NOCC from different sources and of different molecular weights on cadmium toxicity. Sprague-Dawley rats were blocked into 26 groups according to body weight, and were raised for 4 weeks. Cadmium chloride was given at the level of 0 or 400 ppm in diet. Various forms of chitosan and NOCC were given at the level of 0 or 4%(w/w) of diet. Cd toxicity was alleviated by various chitosan and NOCC supplements. However, the alleviating effects were different with fiber source(crab and shrimp), type(chitosan and NOCC), and molecular weight (low, medium, and high). Molecular weight had no significant effect. Compared with shrimp-source-fiber-fed groups, crab-source-fiber-fed groups showed lower Cd concentrations in blood and kidney, lower kidney metallothionein concentration, and lower liver and kidney MT-Cd contents. Compared with NOCC -fed groups, chitosan-fed groups showed lower intestine and liver Cd concentrations, lower liver and kidney MT concentrations and MT-Cd content, and higher fecal Cd excretion. Among cadmium-exposed group, low molecular weight shrimp chitosan group showed low Cd concentrations of liver and kidney, high fecal Cd excretions, and the lowest intestine and liver MT concentrations and liver MT-Cd content. In summary, a crab source fiber was more effective than shrimp source fiber, chitosan was more effective than NOCC, and the most effective one in alleviating Cd toxicity was low molecular weight shrimp chitosan.

• Fisheries and Aquatic Sciences
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• 제27권9호
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• pp.600-613
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• 2024

This study assessed the applicability of medium molecular weight chitosan solution at different concentrations (0.5%, 1%, 1.5% and 2% w/v) in houndfish preservation. Furthermore, by comparing chitosan-coated fish and the uncoated ones (i.e., treated with distilled water [DW] and 1% acetic acid [AA] solution), the study determined the effectiveness of the chitosan coating on the preservation of on-skin houndfish during ice storage for 20 days. The quality of chitosan-coated houndfish was investigated by periodical analysis for microbiological (total viable count), chemical (pH, water holding capacity, total volatile basic nitrogen of refrigerated houndfish, thiobarbituric acid reactive substances, TCA-soluble peptide, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis), physical parameters (hardness, and color), and sensory properties. According to the findings, the methods of using 1.5% and 2% chitosan solutions showed better preservation results than others. These methods were found to be the most effective coatings for maintaining the quality of houndfish compared to the treatments involving DW and 1% AA solution.

• 한국환경보건학회지
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• 제24권3호
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• pp.48-53
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• 1998

Chitin is known as biodegradable natural polymer. But, in spite of various application of chitin from waste marine sources, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. We made various viscosity of chitosan from chitin by change of Mima's method through the deacetylation which is various condition of NaOH concentration, reaction time and temperature. Also, Polyvinyl alcohol/chitosan blend films were prepared by different solution blends containing the ratio of 5, 10, 15 and 20% chitosan and low, medium, high molecular weight of chitosan to find a more useful biodegradable polymer. Thermal and mechanical properties of PVA/chitosan blend films such as DSC, impact strength, tensile strength and morphological changes by SEM were determined. The 10-15% PVA/chitosan(low, medium) blend films were similar to PVA. Also, PVA/chitosan blend films at the laboratory soil test(Pot Test) were completely degraded in month with four kinds of soils by microorganisms.

• Journal of Nutrition and Health
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• 제30권7호
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• pp.770-780
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• 1997

This study was performed to investigate the effect of chitosan and NOCC from different sources and of different molecular weights on lipid metabolism. Sprague-Dawley rats were blocked into 26 groups according to body weight, and were raised for 4 weeks. Cadmium chloride was given at the level of 0 or 400 ppm in diet. Various chitosan and NOCC sources were given at the level of 0%(w/w) of diet. Total serum cholesterol and serum triglyceride concentrations were little affected by chitosan and NOCC supplements. However, HDL-cholesterol concentration and HDL : total cholesterol ratio were increased , and liver lipid, cholesterol , and triglyceride concentration were decreased by chitosan and NOCC supplements. The cholesterol and lipid lowering activity depends on fiber sources(crab and shrimp); type (chitosan and NOCC); and molecular weight(low , medium , and high). Among cadmium-free groups, chitosan-fed groups showed greater activity than NOCC -fed groups in lowering cholesterol and lipid levels, and greater fecal excretion of lipids and bile acids. Crab chitosans were more effective in cholesterol and lipid lowering activity than shrimp chitosans. The group fed high molecular weight crab chitosan showed the highest fecal excretion of lipids and bile acids. This indicated that high molecular weight crab chitosan was most effective in interfering with cholesterol and lipid absorption.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.503-507
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• 2002

Chitosan oligosaccharides (COSs) were prepared and fractionated into three groups of COS [a high molecular weight COS (HMWCOS), medium molecular weight COS (LMWCOS), and low molecular weight COS (LMWCOS)] according to their molecular weight, using an ultrafiltration membrane enzymatic bioreactor designed earlier [8]. Antitumor activity of these COSs was then examined against Sarcoma 180 solid (S180) or Uterine cervix carcinoma No. 14 (Ul4) tumor cell-bearing mice. Among these COSs, MMWCOS with molecular weight range from 1.5 to 5.5 kDa effectively inhibited the growth of both tumor cells in the mice. In addition, the administration of MMWCOS resulted in increased thymus weight among lymphoid organs. The mice treated with MMWCOS showed improved survival rate and larger number of survivors after 40 days of feeding. The most effective of MMWCOS far antitumor activity in the S180- or U14-bearing mice was 20 mg/kg/day or more.

• 한국염색가공학회지
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• 제23권2호
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• pp.90-99
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• 2011

The aim of this study is to develope eco-printing method using natural pigments and chitosan as a natural binder. Three chitosans with different molecular weights were employed to find appropriate conditions including chitosan concentration and pigment/binder ratio. Dye uptake, color and fastnesses of the printed fabrics were evaluated to find optimum conditions within the range of experiments carried out in this study. The effectiveness of chitosan as a printing binder was examined in comparison with color, dye uptake, and fastnesses of conventional synthetic binder and guar gum. It was found that chitosans with low or medium molecular weight were appropriate. Using low molecular weight chitosan, optimum concentrations were 1.7% for charcoal, madder and chlorophyll, whereas 2.2% for ocher, yellow soil, indigo and cochineal. Regardless of molecular weight and concentration of chitosan, the color fastnesess of fabrics printed with mineral pigments were superior to those of the fabrics printed with plant and animal pigments. As pigment/chitosan ratio became higher, rubbing fastness was decreased by 1-3 grade. The colorfastness of printed fabric with chitosan binder was similar to that with synthetic binder, which was higher than that with guar gum.

• 한국식품영양과학회지
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• 제33권2호
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• pp.236-243
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• 2004

양식넙치의 세균성 질병의 원인균주인 Vibrio sp., Edwardsiella tarda 및 Streptococcus sp.를 제주산 양식 넙치로부터 직접 분리하였으며, 이들 세균에 대하여 키토산 및 분자량 크기에 따라 분획된 3종류의 키토산올리고당(HMW-COS, MMW-COS, LMW-COS)의 항균활성을 검토하였다. 키토산과 HMW-COS는 모든 세균에 대한 항균활성이 우수하였으며, 특히 Vibrio sp.과 Sfreptococcus sp.에 대해서 높은 항균활성을 나타내었다. 이들에 대한 결과는 키토산의 항균활성은 분자량에 따라 크게 의존한다는 사실을 보여주었다 E.tarda에 대한 키토산 및 HMW-COS의 항균활성은 처리시간을 증가시킴으로써 항균활성이 증가함을 보였으며, 이들의 항균기 작을 조사하기 위 한 SEM의 관찰에서, 세균들은 키토산에 의해 응집되어 서로 엉켜있는 형태를 보여주고 있었다. 이러한 현상은 키토산 및 HMW-COS가 세균의 증식을 명확하게 억제하고 있음을 보여주는 증거라 할 수 있다. 이것은 지금까지 여러 보고에서 밝혀진 키토산의 항균활성 메카니즘과 일치하는 것이라 판단된다.

• 대한소아치과학회지
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• 제48권2호
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• pp.198-208
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• 2021

이 연구의 목적은 키토산 첨가 수산화칼슘 근관 충전재의Enterococcus Faecalis에 대한 항균 효과 및 물리적 성질을 알아보는 것이다. 저, 중, 고분자량의 키토산 분말을 수산화칼슘 근관 충전재와 혼합하였고, 각 분자량 별로 키토산 분말을 1.0, 2.0, 5.0 wt%로 첨가하였다. E. faecalis를 배양하여 1 × 10⁶ CFU/ml로 조정하였다. 항균 효과 실험을 위해 2.0 wt% 키토산의 3가지 다른 분자량, 3가지 다른 농도의 고분자량 키토산을 수산화칼슘 근관 충전재와 혼합하였다. 기준 파장 600 nm인 570 nm에서 분광광도계를 이용하여 상층액의 흡광도를 측정하였다. 유동성, 피막도 및 방사선 불투과성은 ISO 6876 : 2012에 의거하여 측정하였다. 키토산을 포함하는 모든 분자량 유형의 실험군은 키토산을 첨가하지 않은 대조군에 비해 E. faecalis 성장 억제 효과를 보였다. 고분자량 키토산 첨가 군에서 가장 좋은 항균 효과를 보였다(p < 0.05). 또한 키토산 첨가량이 감소할수록 항균 효과도 감소하였다(p < 0.05). 키토산을 함유하는 수산화칼슘 근관 충전재의 모든 분자량 군은 키토산 함량의 증가 따라 유동성 및 방사선 불투과성이 감소하고 피막도가 증가하는 경향을 보였다. 1.0 wt% 저분자량 키토산의 첨가는 기존 수산화칼슘 근관 충전재와 비교하여 물성에 큰 차이를 보이지 않았다. 연구 결과를 종합하였을 때, 수산화칼슘 근관 충전재에 첨가하여 항균성 강화와 적절한 물성을 얻기 위해선 2.0 wt%의 키토산 분말의 첨가가 적정하다. 키토산의 항균 효과를 고려할 때, 키토산의 근관 치료 및 소아치과 분야에서의 적용을 위한 추가적인 연구가 필요할 것으로 사료되었다.

• 한국환경보건학회지
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• 제25권3호
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• pp.58-63
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• 1999

Biodegradable films were prepared by solution blend method in the weight ratio of chitosan for the purpose of useful biomaterials. The possibility of biomaterials prepared from natural polymer as a skin substitute was evaluated by measuring biocompatibility. These films were inserts in the back of rat and their biodegradability was investigated by the film weight and hematology as a function of time for the biotransformation. The result of rat test showed that medium, high viscosity chitosan induced some suspects of inbiocompatibility in the tissue by goreign body reaction 48 and 72 hours after implantation. Also, we prepared the official burn ointment which is made by low viscosity chitosan. This burn ointment was covered on the skin wound of artificial burn and their effect of healing was investigated by the evaluation of the naked eye and hematological change as a function of time. The result of rats test showed that burn ointments made from chitosan was effective reductio of inflammation than negative group.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.608-611
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• 2000

To separate chitosanoligosaccharides easily by size exclusion, an coencapsulating technology of substrate and enzyme was developed. Chitosan and chitosanase were enveloped in this membrane and the product released to medium by size exclusion. The lower limit of the alginate concentration and the agitation speed were 0.5% and 40 rpm, respectively. Membrane thickness and capsules diameter were $10{\mu}m$ and approx. 3.0mm, 1.5mm, respectively. The molecular weight difference by concentration and cps of alginate were of little significance. And also, the molecular weight of distribution according to enzyme concentration was low concentration of enzyme produced high molecular weight of oligosaccharides. At 1.5mm size of capsule, product diffusion rate to outer part was higher than other capsules. The molecular weight distribution of the released oligosaccharides ranged from 1000 to 6000 Da.