• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.5
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• pp.699-704
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• 2012

In this study, we have proposed a novel decomposition agent composed of Cu(II) and soluble chitosan for organophosphorus chemical agents. Compared to the autohydrolysis, the soluble Cu(II)-Chitosan complex hydrolyzed DFP more effectively. Results show that soluble Cu(II)-Chitosan complex enhances the hydrolysis of DFP in 4~6 folds compared to the autohydrolysis of DFP in buffer solution. This study provides the possibility of using this soluble Cu(II)-Chitosan complex as the environmental friendly decomposition agent which can substitute current DS-2 decomposition agent.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.10
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• pp.1655-1664
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• 2009

Chitosan is an environment-friendly and natural cationic polymer that can be used as a hair cosmetic additive. Healthy hair and damaged hair samples were experimented on according to treatment conditions using a water-soluble chitosan. Chitosan treated hair samples were studied on the physical and mechanical property changes. It is most effective when the water-soluble chitosan treatment was adjusted to the Neutral (pH6.8) or Acid (pH4.5). When the water soluble chitosan was treated at pH4.5, the tensile strength, tensile elongation, and elasticity of decolorized hair all increased. The virgin and damaged hair both changed into elastic and soft hair. The effect of chitosan treatment is more noticeable in the healthy hair than in the damaged hair.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.123-129
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• 1993

Chitosan is known to be one of the natural chelating agents. It is derived from chitin which is a cellulose-like biopolymer distributed widely in nature, especially in shellfish, insects, fungi, and yeast. There are two forms of chitosans, water soluble and insoluble, The purpose of the present study is to investigate whether water soluble chitosan can be applied to reduce the bioabailability of radios-trontium in foods. We compared the effect of water soluble and insoluble chitosans on the absorption of ingested radiostrontium ($^{85}Sr$). Three percent water soluble and insoluble chitosan solutions were given orally, and immediately after $^{85}SrCl_2$ ($0.2{\mu}Ci$) was administered to rats using a orogastric tube. In one group water soluble chitosan solution was given for additional 4 days. And in control group no chitosan was given. Each group consisted of 6 rats. The whole-body retention of $^{85}Sr$, determined by in vivo counting method, was lower in water soluble chitosan group than that of water insoluble chitosan group and that of control. Urinary excretion of $^{85}Sr$ in chitosan-treated rats was higher than that of control. And 5 day ingested group of water soluble chitosan showed least whole body retention of $^{85}Sr$. In conclusion water soluble chitosan was more effective in reducing bioavailability of ingested radiostrontium in the gastrointestinal tract than insoluble chitosan.

• Journal of Nutrition and Health
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• v.36 no.9
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• pp.908-917
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• 2003

It has been proposed that oxidative modification of LDL (oxLDL) plays a significant role in the pathogenicity of atherogenesis. We tested the hypothesis that chitin and chitosan may function as antioxidants with respect to 0.1 mg cholesterol/ml LDL incubated with 5 $\mu$ M Cu$^2$$^{+}$alone or in the P338Dl mouse macrophage system using L-ascorbic acid as a standard classical antioxidant. The degree of oxLDL formation was ascertained by the relative electrophoretic mobility (rEM) in the combination of thiobarbituric acid reactive substances (TBARS) levels, and the cytotoxicity of oxLDL was detected by macrophage viability. The oxLDL uptake and foam cell formation of macrophages were measured by Oil Red O staining. Incubation with Cu$^2$$^{+}$and macrophages increased rEM of LDL and stimulated TBARS formation. Culture of macrophages with LDL in the presence 5 $\mu$ M Cu$^2$$^{+}$induced macrophage death. In cell-free system 200 $\mu$g/ml water-soluble chitosan and chitosan-oligosaccharide blocked oxLDL formation. Water-soluble chitosan and chitosan-oligosaccharide blocked oxLDL formation near-completely relative to L-ascorbic acid, whereas water-soluble chitin and chitin-oligosaccharide had no measurable antioxidant effect. In macrophage system water-soluble chitosan and chitosan-oligosaccharide blocked oxidation of LDL with a significant increase in cell viability, and decreased TBARS in medium. As for the inhibitory effect on macrophage foam cell formation, chitosan and its oligosaccharide, but not watersoluble chitin, revealed the effectiveness. The endothelial expression of lectin-like oxLDL receptor-1 (LOX-1) was tested by Western blot analysis, and chitosan, chitosan-oligosaccharide and chitin-oligosaccharide blocked LOX-1 expression. These results indicate that water-soluble chitosan and its oligosaccharide showed the inhibitory effect on Cu$^2$$^{+}$-induced LDL oxidation of macrophages, and chitosan, chitosan-oligosaccharide and chitin-oligosaccharide had blocking effect on oxLDL receptor expression in the human umbilical vein endothelial system. Thus, water-soluble chitosan and its oligosaccharides possess anti-atherogenic potentials possibly through the inhibition of macrophage LDL oxidation or endothelial oxLDL receptor expression depending on chemical types.l types.

• Textile Coloration and Finishing
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• v.16 no.3
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• pp.22-30
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• 2004

The polyester fabrics were treated with the chitosan with various solubility in optimized treatment condition. The treatment method was discussed to be a high functional finishing for the polyester fabric to obtain the high moisture absorption and anti-microorganism property by evaluating the effect of the chitosan purification method on the yield and anti-microorganism property of the chitosan. On the other hand, soluble polyurethane was added to the chitosan treatment solution and/or plasma pretreatment was done. The addition of soluble polyurethane give a high add-on ratio as well as a linen like effect of treated polyester fabric. The results were as follows: 1. In the treatment of polyester fabric by the chitosan solution, a soluble PU resin and low temperature plasma treatment were done to obtain high binding force between the fabrics and the chitosan. The add-on rate and the moisture absorption ratio of the fabrics treated with the chitosan-PU after treated with the plasma slightly increased more than those of the fabrics treated with the chitosan only. 2. Anti-static property of the fabrics treated with the chitosan decreased rapidly with increasing of the chitosan concentration. The washing fastness of the fabrics treated with the chitosan-PU after treated with the plasma was better than those of the fabrics treated with chitosan only. The wrinkle resistance of the treated fabrics decreased constantly with the concentration of the chitosan. The bending rigidity of the treated fabrics increased greatly. On the treatment of polyester fabric under optimum condition, the microorganism reduction rate kept above 90％ after 10times launderings. 3. As the polyester fabrics which has flat yam was used as a weft yams were treated with the chitosan-PU as give a functional finishing effects such as durability, moisture absorption, anti-static and anti- microorganism property. Treated polyester fabric showed a good functional finishing effect and a linen like property.

• Journal of the Korean Applied Science and Technology
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• v.13 no.2
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• pp.85-92
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• 1996

Chitosan itself has been prepared using chitin, one of the most abundant compounds in nature, as a starting material. We have synthesized the water-soluble chitosan derivative, N-dithiocarboxy chitosan sodium salt, through the reaction of water-soluble chitosan with carbon disulfide in the presence of alkali metal hydroxide. To elucidate this natural polymer capacity of adsorbing heavy metal ions, we have performed adsorption experiments using the water-soluble chitosan derivative various average molecular weight and of different percent contents of sulfur. The effect of pH, adsorption time and temperature on adsorption efficiency was also studied. The adsorbent derived from water-soluble chitosan of average molecular weight ranging $9,000{\sim}120,000$ was shown to have the highest capacity of adsorbing heavy metal ions. On the whole, adsorbing efficiency was increased as the reaction time goes longer and also increased as the reaction temperture goes higer in temperture range of $15^{\circ}C{\sim}45^{\circ}C$. The adsorption capacity at various pH, however, was appeared to vary depending on the heavy metal ions studied Judging from these finding, water-soluble N-dithiocarboxy chitosan sodium salt, a derivative of a biodegradable nature polymer, is believed to be a potential adsorbent for heavy metal ions since it not only is shown to lower the concentration of heavy metal ions to below the drainage quality standard, but also it would not cause acidification and hardening of soil which is one of the detrimental effects of synthetic macromolecular adsorbents present.

• Animal cells and systems
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• v.1 no.2
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• pp.337-340
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• 1997

The purpose of this study is to evaluate whether water soluble chitosan, a natural nontoxic chelator, can reduce fetal contamination of radiostrontium in pregnant mice. Various forms of water soluble chitosans (10% or 1% powder, or 1% solution) were given to pregnant mice before or after contamination of 0.005 uCi/B.W(g) Sr-85. Transplacental transfer of Sr-85 to fetus was $6.8{\pm}2.7%$ of injected dose, when Sr-85 was administered at the 20th day of pregnancy. Fetal radioactivity was significantly reduced when mother mice were treated with water soluble chitosan before contamination of Sr-85. Water soluble chitosans of 10% or 1% powder, or 1% solution significantly reduced fetal retention of Sr-85 to $2.3{\pm}0.7%$, $2.7{\pm}0.8%$, and $2.0{\pm}0.9%$, respectively. However, fetal contamination was not reduced, when water soluble chitosans of 10% or 1% powder, or 1% solution were administered after maternal contamination of Sr-85. From these data we can conclude that water soluble chitosan could reduce fetal contamination of radiostrontium in pregnant mice, when given before the pregnant mice were exposed to radiostrontium.

• The Korean Journal of Food And Nutrition
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• v.13 no.3
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• pp.242-248
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• 2000

수산물 가공시 흘러나오는 폐수 중에 함유되어 있는 수용성 단백질을 chitosan에 흡착시키기 위하여 albumin과 hemoglobin, albumin-myoglobin 혼합단백질을 이용하여 chitosan과의 흡착 및 chitosan 제조조건에 따른 흡착효과와 chitosan의 수용성 단백질 흡착에 미치는 인자를 살펴본 결과는 다음과 같다. Chitosan위 탈아세틸화 조건을 60, 70, 80%로 달리하여, albumin, hemoglobin, albumin-myoglobin 혼합용액에 적용했을때 chitosan의 탈아세틸화도가 높을수록 chitosan과 단백질 사이의 흡착률은 높게 나타났다. 초음파 처리에 의하여 chitosan의 분자량이 작을수록 chitosan과 단백질 사이의 흡착률은 높게 나타났다. pH변화에 따른 chitosan과 수용성 단백질의 흡착률은 albumin 및 albumin-myoglobin 혼합용액에서는 pH 4.0에서, hemoglobin용액에서는 pH 7.0에서 흡착률이 높게 나타났다 chitosan과 수용성단백질과의 흡착에서 반응시간은 albumin및 albumin-myoglobin 혼합용액에서는 4시간, hemoglobin용액에서는 3시간까지 흡착률이 증가하였고, 그 이후의 시간이 경화하여도 흡착률의 증가는 거의 보이지 않았다. 수용성 단백질 용액에 NaCl 농도를 0.1M에서 1.0M로 증가시켜 첨가했을때 염의 농도가 높을수록 chitosan과 단백질 사이의 흡착이 잘 일어나지 않았다.

• Polymer(Korea)
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• v.28 no.4
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• pp.291-297
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• 2004

Water-soluble chitosan micro spheres were prepared by emulsification of chitosan solution in mineral oil followed by cross linking reaction with different amount of the cross linking agent (glutraraldehyde), different chitosan concentration. Then, the physicochemical properties such as morphological change by degradation, drug loading efficiency, and drug release profiles were investigated with the drug loaded water-soluble chitosan microspheres. Norfloxacin loaded water-soluble chitosan micro spheres showed excellent drug entrapping capacities without burst release caused by surface bound drug. The absence of the surface bound drug also confirmed by X-ray diffraction study. Degradation and drug release studies showed that the amount of the crosslinking agent played a crucial role for drug loading, release and degradation. The water-soluble chitosan micro spheres showed more sustained drug release profiles with slower degradation and larger particle size by increasing crosslinking agent.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.199-205
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• 2004

The effect of chitosan on enzymatic activities and on bioactive compounds was characterized during germination at $25^{\circ}C$ for 7 days to search for a method to produce a germinated black rice. The germination rate was reduced by the addition of lactate and chitosan. The rotting rate was greatly decreased by chitosan, suggesting that the addition of chitosan into a germination solution might be an effective method for controlling fungal contamination during the germination of cereals. The addition of 100 and 200 ppm chitosan increased $\alpha$-amylase activity after 7 days by up to 152 % and 197 %, respectively. The activities of $\beta$-amylase and $\beta$-glucosidase were lower with 200 ppm chitosan than in distilled water and 100 ppm lactate. The amount of total soluble phenolics and total flavonoids decreased rapidly for four days and thereafter remained constant until the seventh day. The antioxidant activity of germinated black rice, in terms of hydrogen-donating activity, increased slowly and did not correspond to the changes of total soluble phenolics and total flavonoids. The amount of phytic acid was reduced by the addition of 200 ppm chitosan compared to distilled water, indicating that chitosan could be used as an elicitor for the increase of phytase activity during the germination of black rice.