• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.7-14
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• 2008

Purpose: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. Materials and Methods: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. Results: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. Conclusion: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

• Biomedical Science Letters
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• v.17 no.3
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• pp.211-216
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• 2011

The chitosan-coated liposomes (chitosomes) were designed to improve the stability in the gastrointestinal (GI) tract and to enhance the efficacy for oral drug delivery of liposomes. The phosphatic acid (PA)-incorporated anionic liposomes were surface-coated with water soluble chitosan (WSC) by electro-ionic interaction. The shape of the chitosomes observed by transmission electron microscopy (TEM) was spherical in all the formulations and the coating layer by WSC could be founded through TEM images. The mean size and the zeta potential values of the chitosomes increased significantly with depending on the content of WSC added for coating the liposomes. The stability of the chitosomes in the GI tract was confirmed through the change of relative turbidity of the liposomal suspension. The plain liposomes (plasomes) suspension without adding WSC clearly showed the change of relatively turbidity in simulated gastric fluid (SGF), while the change degree of turbidity of the chitosomes in the SGF decreased as increasing of WSC content added for coating liposome. In the 5-CF release study from the plasomes and chitosomes, the plasomes released >90% of the initial 5-CF content at 4 h of release measurement. In contrast, the chitosomes released below 40% of initial content of 5-CF. In conclusion, these results indicate that the chitosomes can be used as a potential carrier for effective oral drug delivery.

• Polymer(Korea)
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• v.36 no.6
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• pp.699-704
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• 2012

Double-layered polymeric carrier was designed for release control of hydrophilic drug in oral administration. Biopolymeric chitosan and alginate were examined as polar absorbents, poly(D,L-lactide) as a hydrophobic shell, and theophylline and diclofenac sodium as loading drugs. The fabrication of the carriers was prepared in the form of double-layered microsphere for delayed and successively extended release, which consisted of outer shell of poly(D,L-lactide) and inner core of alginate or chitosan with drugs. Morphologies and drug-release behaviors of the carriers were investigated, which were influenced by a combination of polarity between carrier and drug. It was confirmed that the relative polarities of the carriers, the drugs, and the environmental pH affected significantly the drug-release property.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.978-982
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• 2011

In order to enhance the target action of chitosan-based drug, this paper firstly prepared phenylalanyl-glycylchitosan (Phe-Gly-CS) by grafting the key intermediate, bromoacetyl-phenylalanine (BA-Phe) onto chitosan. Then the target sugar molecule, lactobionic acid (LA), was grafted to Phe-Gly-CS and the topic compound lactobionic acid grafted phenylalanyl-glycyl-chitosan (Phe-Gly-CS-LA) was finally obtained in a yield of 78.8%. The product were characterized by FTIR, MS and 1H NMR. The preparing condition of BA-Phe was optimized as follows: the best pH was 10-11, the optimum temperature was $-4^{\circ}C$, the reaction time was 1.5 h.

• KSBB Journal
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• v.10 no.4
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• pp.461-467
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• 1995

In this study, the release experiments of drug were operated in the phosphate buffer solutions of pH 7.4 and pH 1.2 by using drug carriers(chitosan, chitosan hydrochloride, and sulfonated chitosan)coated by poly(DL-lactide) with prednisolone for delivery drug. The release time of drug was more delayed in pH 7.4 than in pH 1.2. The release time of according to the kinds of drug carrier was delayed in the order of chitosan, sulfonated chitosan, and chitosan hydrochloride. In short, the formulation allows biodegradable coated monolithic polymetic matrices to suppress the burst effect of the drug release mechanism, which led to the sustained release pattern.

• Macromolecular Research
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• v.12 no.6
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• pp.573-580
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• 2004

To prepare chitosan-based polymeric amphiphiles that can form nanosized core-shell structures (nanopar­ticles) in aqueous milieu, chitosan oligosaccharides (COSs) were modified chemically with hydrophobic cholesterol groups. The physicochemical properties of the hydrophobized COSs (COSCs) were investigated by using dynamic light scattering and fluorescence spectroscopy. The feasibility of applying the COSCs to biomedical applications was investigated by introducing them into a gene delivery system. The COSCs formed nanosized self-aggregates in aqueous environments. Furthermore, the physicochemical properties of the COSC nanoparticles were closely related to the molecular weights of the COSs and the number of hydrophobic groups per COS chain. The critical aggregation concentration values decreased upon increasing the hydrophobicity of the COSCs. The COSCs effi­ciently condensed plasmid DNA into nanosized ion-complexes, in contrast to the effect of the unmodified COSs. An investigation of gene condensation, performed using a gel retardation assay, revealed that $COS6(M_n=6,040 Da)$ containing $5\%$ of cholesteryl chloroformate (COS6C5) formed a stable DNA complex at a COS6C5/DNA weight ratio of 2. In contrast, COS6, the unmodified COS, failed to form a stable COS/DNA complex even at an elevated weight ratio of 8. Furthermore, the COS6C5/DNA complex enhanced the in vitro transfection efficiency on Human embryonic kidney 293 cells by over 100 and 3 times those of COS6 and poly(L-lysine), respectively. Therefore, hydrophobized chitosan oligosaccharide can be considered as an efficient gene carrier for gene delivery systems.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1284-1289
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• 2004

Galactosylated chitosan-graft-poly(vinyl pyrrolidone) (GCPVP) was synthesized and characterized for hepatocyte-targeting gene carrier. GCPVP itself as well as GCPVP/DNA complex had negligible cytotoxicity regardless of the concentration of GCPVP and the charge ratio, but GCPVP/DNA complex had slightly cytotoxic effect on HepG2 cells only in the case of the higher charge ratio and 20 mM of $Ca^{2+}$ concentration used. Through the confocal laser scanning microscopy, it is shown that the endocytosis by interaction between galactose ligands of GCPVP and ASGPR of the hepatocytes was the major route of transfection of GCPVP/F-plasmid complexes.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.178-178
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• 2006

Chitosan has been investigated as a non-viral vector because it has several advantages such as biocompatibility, biodegradability and low toxicity with high cationic potential. However, low specificity and low transfection efficiency of chitosan as a DNA carrier need to be overcome for clinical trials. In this study, chemical modification for enhancement of cell specificity and transfection efficiency was investigated. Also, the chitosan derivative formulations in vivo were included.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.104-109
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• 1998

The objective of this study was to examine the effect of polymer coating on the initial microorganism attachment and the biofilm growth. Such as nonion(polyacrylamine), anion(CMC-Na) and cation polymer coagulant(chitosan and PEI) were used for coating material of the support carrier(acryl plate). When polymer coagulant was coated with 5, 10, 20, 35, 50, 100 and 200 mg/l on the surface of acryl plate, initial microorganism attachment increased and optimum concentration for the attachment was 35 mg/l. Biofilm growth experiments were conducted with the substrate loading of 12.7gSCOD/$m^2\cdot$ day using RBC. The polymer coagulants such as CMC-Na, polyacrylamide, PEI and chitosan coating on the acryl plate facilitated the biofilm growth of microorganisms. Until the biofilm dry weight grows up to 0. 0038g/cm$^2$, biofilm growth on the plate coated with cation polymer like chitosan was better than that on the coated plate of nonion(polyacrylamine), anion(CMC-Na) polymer coagulant.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.964-968
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• 2002

Colon drug delivery is advantageous in the treatment of colonic disease and oral delivery of drugs unstable or suceptible to enzymatic degradation in upper GI tract. In this study, multilayer coated system that is resistant to gastric and small intestinal conditions but can be easily degraded by colonic bacterial enzymes was designed to achieve effective colon delivery of prednisolone. Variously coated tablets containing prednisolone were fabricated using chitosan and cellulose acetate phthalate (CAP) as coating materials. Release aspects of prednisolone in simulated gastrointestinal fluid and rat colonic extracts (CERM) were investigated. Also, colonic bacterial degradation study of chitosan was performed in CERM. From these results, a three layer (CAP/Chitosan/CAP) coated system exhibited gastric and small intestinal resistance to the release of prednisolone in vitro most effectively. The rapid increase of prednisolone in CERM was revealed as due to the degradation of the chitosan membrane by bacterial enzymes. The designed system could be used potentially used as a carrier for colon delivery of prednisolone by regulating drug release in stomach and the small intestine.