• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.3 s.151
• /
• pp.386-395
• /
• 2006

Chitosan, a natural polymer has been used to nonwoven fabrics based polypropylene for sanitary top sheets. The changes in mechanical properties relating to the surface structure of functionally improved nonwoven fabrics were investigated with respect to the molecular weight and concentration of chitosan that was used. Low molecular weight(LMW) chitosan treated fabric was found to be evenly coated on the fabrics. It was shown that the bending and shearing characteristics of chitosan treated fabrics increased, which helped to make it stronger and harder, while shape stability improved following treatment using high molecular weight(HMW) chitosan. And the surface structure of treated fabrics was smooth and the sensitivity of its bulk improved somewhat. The treated fabrics were not overly stiff because the increase in Koshi value was not considerable compared to that of the bending characteristics. In the change of hand value relating to chitosan treated fabrics, THV generally improved. In the case of a 0.5$\%$ chitosan, HMW chitosan treated fabrics produced better THV than LMW chitosan treated fabrics. However, in the case of a 1.0$\%$ chitosan, THV of LMW chitosan treated fabrics produced outstanding results.

• Korean Journal of Food Science and Technology
• /
• v.28 no.5
• /
• pp.888-896
• /
• 1996

This study was conducted to investigate the preservative effects of low molecular weight chitosan with and without other preservatives on kimchi at $10^{\circ}C$ during 12 days of fermentation. The pH and titratable acidity of kimchi with preservatives (PSV) were higher and lower, respectively, than those of control kimchi (CON). The decrease in reducing sugar content was more remarkable in CON than in PSV as the fermentation proceeded. Contents of lactic acid and acetic acid were lower in PSV, especially in kimchi with chitosan dissolved in acetic acid (CH-B) and in the one containing both chitosan and Na-benzoate (CHS) than those in CON. The numbers of total viable cells, Leuconostoc sp. and Lactobacillus plantarum were higher in CON than those in PSV. Sensory firmness and green flavor were significantly lower in CON than in CH-B and CHS. Sourness and staled flavor of CH-B and CHS tended to be lower than those of other kimchi samples.

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

• Journal of Convergence for Information Technology
• /
• v.11 no.6
• /
• pp.188-197
• /
• 2021

In this study, the optimal conditions for hair dyeing using sappan wood (Caesalpinia sappan L.) powder were determined, and then the effect of chitosan treatment on the hair dyeing properties of sappan wood powder was investigated. Treatment of sappan wood powder and water with the ratio of 1:3 (w/w) at 40℃ for 60 minutes was found to be the most effective to hair dyeing. In addition, the pretreatment of low molecular weight (~30 kDa) chitosan at a concentration of 1% (w/w) prior to treatment with sappan wood powder effectively improved and maintained the hair dyeing properties of sappan wood. In conclusion, the low molecular weight chitosan is considered to be of great help as a mordant in improving the dyeing efficiency and retention of sappan wood powder in hair dyeing.

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

• Applied Chemistry for Engineering
• /
• v.31 no.5
• /
• pp.475-480
• /
• 2020

Chelates synthesized with Cu(II) ion and lactic acid or chitosan were applied to the hydrolysis of organophosphate simulant, DFP (diisopropyl fluorophosphate). Under the homogeneous reaction condition, Cu(II)-lactic acid chelate hydrolyzed DFP with the half life time of 37.1 min. Cu(II)-LMWS chitosan chelate was synthesized with 1 kDa molecular weight of chitosan, which showed low solubility, and then crystallized. The half life time for hydrolyzing DFP using Cu(II)-LMWS chitosan was 32.9 h indicating that the reaction rate is enhanced as much as 16 times more than that of using 18 kDa chitosan-Cu(II) complex. Under the homogeneous reaction condition, the half life time of Cu(II)-LMWS chitosan was 8.75 h. Therefore, we found out that the solubility of Cu(II)-LMWS chitosan makes the difference in the reaction rate as much as 4 times.

• Journal of Environmental Health Sciences
• /
• v.25 no.3
• /
• pp.58-63
• /
• 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.

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.545-545
• /
• 2003

Chitosan is applied as a dressing for oral mucous wound and a tampon following radical treatment of maxillary sinus. Furthermore, it is being investigated as an absorbing membrane for endodontic and periodontic surgeries. A few studies have reported osteoconduction and osteogenesia at the site of chitosan implant in vivo. However, compared with soft tissue healing processes, the mechanisms concerning effects of chitosan for biological mineralization have not yet been resoil In the present study, we studied the gene expression pattern using cDNA microarray and RT-PCR analyses in hard tissue forming osteoblasts cultured with water-soluble and low molecular weight chitooligosaccharide. cDNA microarray analysis revealed that 16 genes were expressed at 〉1.5-fold higher signal ratio levels in the experimental group compared with the control group after 3 days. RT-PCR analysis showed that chitosan oligomer induced an increase in the expression of two genes, CD56 antigen and tissue-type plasminogen activator. Furthermore, the expression of mRNAs for BMP-2 was almost identical in the experimental and control groups after 3 days of culture, but slightly increased after 7 days of culture with chitosan oligomer. These results suggest that a super-low concentration of chitooligosaccharide could modulate the activity of osteoblastic cells through mRNA levels and that the genes concerning cell proliferation and differentiation can be controlled by water-soluble chitosan.

• Restorative Dentistry and Endodontics
• /
• v.38 no.1
• /
• pp.36-42
• /
• 2013

Objectives: This study evaluated the antibacterial effect and mechanical properties of composite resins ($L_{CR}$, $M_{CR}$, $H_{CR}$) incorporating chitosan with three different molecular weights (L, Low; M, Medium; H, High). Materials and Methods: Streptococcus (S). mutans 100 mL and each chitosan powder were inoculated in sterilized 10 mL Brain-Heart Infusion (BHI) solution, and was centrifuged for 12 hr. Absorbance of the supernatent was measured at $OD_{660}$ to estimate the antibacterial activities of chitosan. After S. mutans was inoculated in the disc shaped chitosan-containing composite resins, the disc was cleansed with BHI and diluted with serial dilution method. S. mutans was spread on Mitis-salivarius bacitracin agar. After then, colony forming unit (CFU) was measured to verify the inhibitory effect on S. mutans biofilm. To ascertain the effect on the mechanical properties of composite resin, 3-point bending and Vickers hardness tests were done after 1 and 3 wk water storage, respectively. Using 2-way analysis of variance (ANOVA) and Scheffe test, statistical analysis was done with 95% significance level. Results: All chitosan powder showed inhibition effect against S. mutans. CFU number in chitosan-containing composite resins was smaller than that of control resin without chitosan. The chitosan containing composite resins did not show any significant difference in flexural strength and Vickers hardness in comparison with the control resin. However, the composite resin, $M_{CR}$ showed a slightly decreased flexural strength and the maximum load than those of control and the other composite resins $H_{CR}$ and $L_{CR}$. Conclusions: $L_{CR}$ and $H_{CR}$ would be recommended as a feasible antibacterial restorative due to its antibacterial nature and mechanical properties.

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