• Proceedings of the Korean Fiber Society Conference
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• 2000.04a
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• pp.201-204
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• 2000

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1729-1734
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• 2008

Chitosan, a cationic polysaccharide, has been widely used as a dietary supplement and in a variety of pharmacological and biomedical applications. The antifungal activity and mechanism of action of low molecular weight water-soluble chitosan (LMWS-chitosan) were studied in fungal cells and vesicles containing various compositions of fungal lipids. LMWS-chitosan showed strong antifungal activity against various pathogenic yeasts and hyphae-forming fungi but no hemolytic activity or cytotoxicity against mammalian cells. The degree of calcein leakage was assessed on the basis of lipid composition (PC/CH; 10:1, w/w). Our result showing that LMWS-chitosan interacts with liposomes demonstrated that chitosan induces leakage from zwitterionic lipid vesicles. Confocal microscopy revealed that LMWS-chitosan was located in the plasma membrane. Finally, scanning electron microscopy revealed that LMWS-chitosan causes significant morphological changes on fungal surfaces. Its potent antibiotic activity suggests that LMWS-chitosan is an excellent candidate as a lead compound for the development of novel anti-infective agents.

• Macromolecular Research
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• v.14 no.1
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• pp.66-72
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• 2006

The purpose of this study is to develop novel nanoparticles based on polyion complex formation between low molecular weight water-soluble chitosan (LMWSC) and all-trans retinoic acid (atRA). LMWSC nanoparticles encapsulating atRA based on polyion complex were prepared by mixing of atRA into LMWSC aqueous solution using ultrasonication. In FTIR spectra, the carbonyl group of atRA at 1690 $cm^{-1}$ disappeared or decreased when ion complexes were formed between LMWSC and atRA. In ${1}^H$ NMR spectra, specific peaks of atRA disappeared when atRA-encapsulated LMWSC (RAC) nanoparticles were reconstituted into $D_{2}O$ while specific peaks both of atRA and LMWSC appeared in $D_{2}O$/DMSO (1/3, v/v) mixture. XRD patterns also showed that the crystal peaks of atRA were disappeared by encapsulation into LMWSC nanoparticles. LMWSC nanoparticles encapsulating atRA have spherical shapes with particle size below 200 nm. The mechanism of encapsulation of atRA into LMWSC nanoparticles was thought to be an ion complex formation between LMWSC and atRA. LMWSC nanoparticles showed high atRA loading efficiency over 90$\%$ (w/w). AtRA was continuously released from nanoparticles over 10 days. In in vitro cell cytotoxicity test, free atRA showed higher cytotoxic effect against CT 26 colon carcinoma cell line on 1 day. However, RAC nanoparticles showed similar cytotoxicity against CT 26 cells on 2 day. These results suggest the potential for the introduction of LMWSC nanoparticles into various biomedical fields such as drug delivery.

• Polymer(Korea)
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• v.31 no.5
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• pp.454-459
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• 2007

Gene therapy using low molecular weight water soluble chitosan (LMWSC) as polycationic polymer shows good biocompatibility, but low transfection efficiency. The mechanism of folic acid (FA) uptake in the cells to promote targeting and internalization could improve transfection rates. The objective of this study was to synthesize and characterize the WSCFA-DNA complex and evaluate their cytotoxicity, in vitro. In $^1H-NMR$ spectra, specific peaks appeared both of FA and LMWSC in $D_2O$. WSCFA nanoparticles have spherical shapes with particle size show below 110 nm. In the cell cytotoxicity test, the WSCFA-DNA complex showed high cell viability, in vitro. Gel electrophoresis showed condensed DNA within the carriers. hi vitro transfection efficiency was assayed by fluorescence spectroscopy WSCFA nanoparticles have less cytotoxicity, good DNA condensation and particle size around 110 nm, which makes them a promising candidate as a non-viral gene vector.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.178-183
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• 2002

A high molecular ar weight water-soluble chitosan (WSC) with an average molecular weight of 300 kD and a deacethylation level of over 90% was produced using a simple multi-step-membrane separation process. It is known that WSC prevents obesity induced by a high-fat diet. Consequently, this study investigated whether or not WSC improved the ovarian dysfunction caused by obesity in mice. The mice were fed a high density protein and lipid diet for weeks, followed by the administration of WSC at 480 mg/kg body weight per day for 4 days. Thereafter, the changes in body weight, ovulation rate, in vivo and in vitro fertilization and emboryonic development were measured . WSC markedly reduced the body weight of obese mice fed with a high-fat diet, but not in mice fed with a normal diet. WSC had siginificant effects on the ovulation rate, both the in vivo and in vitro fertilization rates and embryonic development. These results indicate an improvement in the ovarian and oviduct dysfunction caused by obesity, and suggest an adjustment in the internal secretions and metabolic functions.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.594-597
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• 2004

Effects of various levels and molecular weights (MWs) of chitooligosaccharides and chitosan with pork salt-soluble protein (SSP) on pH, moisture (%), viscosity, and hardness of protein-chitosan mixtures were determined in a model study. Mixtures of 0.15, 0.3, and 0.45% chitosan at various MWs (Low, 1.5 kDa; Medium, 30-50 kDa; High, 200 kDa) were dissolved in 3% SSP solution for measurement of pH and viscosity at $20^{\circ}C$. pH value increased with addition of 0.45% low MW of chitooligosacchearides into SSP (p<0.05), whereas decreased with addition of 0.45% medium MW and 0.3% or higher level of high MW chitosan. Viscosity increased with addition of more than 0.3% either medium or high MW chitosan (p<0.05), as compared to mixture with low MW chitolligosaccharide and control (p<0.05). No differences in gel pH, moisture, and hardness values were observed among treatments (p>0.05). Further study will be performed to evaluate rheological properties actual meat products with various levels and MWs of chitosan.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.86-87
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• 2000

Chitosan (deacetylated form of chitin) possesses strong antibacterial activities such as antimicrobial effect, antifungal effect and the induction of plant defense response. Chitosan itself, however, has high molecular weight and viscosity as well as water-insolubility, These natures may restrict applications in various fields, especially in in vivo system. While the hydrolysates of chitosan, chitooligosaccharides (COS) are not only lower in the molecula. weight and viscosity, but also water-soluble. Thus, they would be expected more efficient absorption in vivo. Besides several documents have been reported antibacterial activities of COS against microorganisms (Kendra et al., 1989; Uchida et al., 1989). (omitted)

• Polymer(Korea)
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• v.27 no.5
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• pp.405-412
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• 2003

Poly(vinyl alcohol) (PVA) and N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride (HTCC), a water soluble chitosan derivative synthesized by the reaction of quaternary ammonium compound with chitosan, were blended using water as a solvent and the PVA/HTCC blend films with various compositions were prepared by solution casting method. The miscibility between the two polymers and the thermal properties of the blend films were investigated using FT-IR, DSC, DMA, and TGA. Single glass transition temperatures and single melting temperatures of the blend films along with the strong and clear film state for the whole composition of blending ratios suggest the miscibility between PVA and HTCC. The PVA/HTCC blend films with HTCC content of 1% and greater showed excellent antimicrobial activity.

• Macromolecular Research
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• v.17 no.4
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• pp.265-270
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• 2009

Noble thermosensitive nanoparticles, based on a PNIPAAm-co-AA core and a chitosan shell structure, were designed and synthesized for the controlled release of the loaded drug. PNIPAAm nanoparticles containing a carboxylic group on their surface were synthesized using emulsion polymerization. The carboxylic groups were conjugated with the amino group of a low molecular weight, water soluble chitosan. The particle size of the synthesized nanoparticles was decreased from 380 to 25 nm as the temperature of the dispersed medium was increased. Chitosan-conjugated nanoparticles with $2{\sim}5$ wt% MBA, a crosslinking monomer, induced a stable aqueous dispersion at a concentration of 1mg/1mL. The chitosan-conjugated nanoparticles showed thermo sensitive behaviors such as LCST and size shrinkage that were affected by the PNIPAAm core and induced some particle aggregation around LCST, which was not shown in the NIPAAm-co-AA nanoparticles. These chitosan-conjugated nanoparticles are also expected to be more biocompatible than the PNIPAAm core itself through the chitosan shell structures.

• KSBB Journal
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• v.10 no.5
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• pp.525-532
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• 1995

Chitosan derivative, of a sulfated N-acetyl chitosan was synthesized, and the inhibitory effects of this compound on the experimental and spontaneous lung metastallc B16/BL6 melanoma bearing mice were investigated. Position of substitution with sulfate in water-soluble sulfated derivatives of chitosan were analysed by 13C-nmr. The structure of N-acetyl chitosan 3,6 0-disulfate were confirmed. The tumor growth inhibition of B16/BL6 melanoma cells has been shown at the highest level of 77.6% when sulfated N-acetyl chitosan were administered at the dose of 100mg/kg. In the lung metastasls, the sulfated N-atetyl chitosan was administered to C57BL/6B mice bearing B16/BL6 melanoma cells by I.V. injection and the number of metastasis foci of melanoma were decreased by the dose dependent manner ranging from 20 to 100mg/kg. In the spontaneous metastasis, I.V. administrations of sulfated N-acetyl chitosan after tumor inoculation resulted in marked reduction of metastatic colonies. A sulfated N-acetyl chitosan was able to partially inhibit the tumor cell adhesion by migration to laminin. These results suggested that chitosan derivative, a sulfated N-acetyl chitoasn was able to inhibit to the experimental and spontaneous metastasis models as well as cell adhesion ability.