The effects of chitosan upon the experimentally induced differentiation of MDPC-23 cells, derived from mouse dental papilla cells, were investigated by RT-PCR, observations of cell morphology and Alizaline red-S staining. Chitosan was found to significantly increase and accelerate the expression of ALP mRNA but decrease the ColI transcript levels, as compared with the control, in a time-dependent manner during the differentiation of MDPC-23 cells. Chitosan also significantly downregulated ON mRNA expression and accelerated mineralization in differentiating MDPC-23 cells. These results suggest that chitosan facilitates odontoblast differentiation and mineralization and may have potential clinical applications as a dentin regeneration material.

Alginate-chitosan blend containing coconut-based activated carbon was prepared as a drug delivery carrier in order to improve the loading and releasing capacity of the drug. The activated carbon was incorporated as effective adsorbent for drug due to the extremely high surface area and pore volume, high adsorption capacity, micro porous structure and specific surface activity. Alginate-chitosan blend containing coconut-based activated carbon showed the sustained release for a longer period. Alginate-chitosan blend showed higher release of drug as the pH increased and higher release of drug as the content of chitosan decreased due to the pH-dependent solubility of blend components.

Superporous Hydrogels (SPHs) have been extensively investigated for various biomedical applications due to their fast swelling and superabsorbent properties. In this study, glycol chitosan that is one of most abundant natural polymers was used as a cross-linking agent instead of bisacrylamide (BIS), which is a broadly used crosslinking agent for preparation of SPHs. Glycol chitosan was modified to have reactive vinyl groups by chemical conjugation with glycidyl methacrylate (GMA). The vinyl group-containing glycol chitosan (GC-GMA) was characterized by FT-IR and 1H-NMR measurements. SPHs have been prepared in various synthetic conditions to establish the optimum synthetic process for making superporous structure, where the inner pores are interconnected to each other to form a open channel structure. Various SPHs with different GC-GMA contents have been successfully prepared and have been observed to show faster swelling properties than other conventional SPHs. From the study on the swelling behavior of SPHs, the GC-GMA content is considered to be an important factor for controlling their swelling properties.

Taegwondo uniforms need powerful durability in fabrics against friction and shock because of higher exercising power. Therefore, in this study we developed more comfortable Taegwondo uniform for functional fabrics (deodorization rate, antibacterial activity and static charge). Chitosan is a deacetylated product of chitin, has widely been used in the biomedical sector, food industry, and textile industry. For the purpose of this study, we used the chitosan, which was congenial to the human body. Then, we compared the differences between the chitosan treated fabrics and non treated fabrics of Taegwondo uniform(100% polyester, 65% polyester/35% cotton). Chitosan was dissolved in 1% acetic acid. Also, the fabrics were washed using distilled water. Afterward, its treatment with chitosan was completed by padding the sample to its wet pick-up at 80±5% and by heating 150℃ for 3 minutes. The chitosan treated Taegwondo uniform was improved on deodorization rate than non treated uniform. And the chitosan treated Taegwondo uniform was improved remarkably the antibacterial activity in all samples. In the further researches, the static charge was reduced in chitosan treatment uniform.

실리카 입자를 기공 형성제로 사용하여 물리적 강도와 단백질 결합용량이 높은 다공성 키토산 및 키틴 친화 막을 제조하였다. 키토산 친화 막의 BSA 단백질 결합용량은 최대 21.8mg/mL이었으며, 키틴 친화 막의 lysozyme 효소 결합용량은 최대 26.1mg/mL이었다. 제조된 다공성 키토산 및 키틴 친화 막을 사용하여 단백질 용액의 loading 유량, loading 양 및 농도 변화에 따른 BSA와 lysozyme의 친화 막 여과 크로마토그래피 분리 실험을 수행하였다. 친화 막 여과 크로마토그래피 분리 실험을 통해 얻어진 loading/washing/elution의 단계로 구성된 일련의 크로마토그램으로부터 단백질 용출량과 결합수율을 구하였다. 키토산 및 키틴 친화 막에의 BSA 및 lysozyme 단백질의 결합량과 결합수율은 loading용액의 유량이 작을수록, 주입량 및 농도가 클수록 증가하였다. 이 결과로부터 실리카 입자를 기공 형성제로 사용하여 제조된 다공성 키토산 및 키틴 막은 단백질의 대규모 여과 크로마토그래피 분리를 위한 친화 막으로서 효과적인 활용이 기대된다.

Many researchers are interested in wound healing in the t reatment of burns, prevention of post surgical adhesions and cosmetic s urgery by excess collagen production and scar formatlOn Synthetic epidermal substi tutes with cultured epi thelial cells seem to be an attractive strategy since keratinocytes have been demonstrated to modulate fibroblast growth and collagen synthesis. Bioa bsorbable and biocompatible chitosan structurally mimics hyaluronic acid. Recently, a bio compatible synthesi zecl ch itosa n-PVP(polyvinyl pyrrolidone) hydrogels demonstrated in vitro biocompat ibi li ty for bio medical applications . However. there is no re port on this hydrogeJ"s ability to modulate human gingival fibroblast growth. The purpose of this study were to investigate different growth modulation between human gingival fibroblast and normal human oral keratinocyte by chitosan- PVP hydrogel, and to apply this biocompatible synthetic polymer to oral and maxillofacial wound healing. We have synthesized a hydrogel from chitosan-PVP and examined its effect on human gingival fibroblast growth modulation in vitro. Non-toxic and biocompatible hydrogel with human gingival fi broblasts and epithelial cells was tested by MTT assay. HGF showed a higher growth proliferation than that of NHOK after cell seeding. In MTT assay, 30% hydrogel leach out products showed a higher cellular viability in NHOK than that of any other products. In MTT assay, 30% hyclrogel leach out products showed relatively lower cellular viability of HGF ln growth profile, NHOK showed about 7 fo lcls higher than HGF after 1 day, while about 2 fo lds higher after 5 days. And also NHOK showed above about 70% cell ular via bility from 1 to 7 days. It suggested that Chitosan-PVP hydrogel would inhibit relatively the growth of HGF and s timulate the growth of NHOK_ This phenomenon may prove to be of use in wound management 0 1' oral and maxillofacial area as epitheli al substitutes.

The process of coprecipitation of biocomposite hydroxyapatite/chitosan from aqueous solution at low temperature in alkali environnement was examined. We have shown that initially we have the formation of amorphous octocalcium phosphates and the transferring from OCP to amorphous calcium phosphate , and then from TCP to calcium-deficient hydroxyapatite and hydroxyapatite . The transformation of ACP to HAP was inhibited in the presence of chitosan. The result suggests that there is an affinity binding between ACP and chitosan and subsequently blocking the active growth site of ACP.

실리카 입자를 기공 형성제로 사용하여 다공성 키토산 및 키틴 막을 제조하였다. 다공성 막의 제조는 다음의 3단계 절차로서 수행되었다: (1) 키토산 용액에 실리카 입자를 첨가시켜 필름을 형성시킨 후, (2) 이 필름을 알카리 용액에 침지시켜 실리카 입자를 제거하여 다공성의 키토산 막을 제조하였으며, (3) 다공성 키토산 막을 acetic anhydride를 사용하여 아세틸화시킴으로서 다공성 키틴 막을 제조하였다. 물리적 강도가 우수하고, 적절한 순수 투과량을 갖는 다공성 키토산 막과 키틴 막의 최적 제막조건이 제시되었다. 단백질 친화성을 부여하기 위해 다공성 키토산 막에 반응성 염료인 Cibacron Blue 3GA를 고정화시켰으며, BSA 단백질 및 lysozyme 효소의 흡착실험을 수행하여 친화 키토산 막 및 키틴 막의 단백질 결합용량을 측정하였다. 친화 키토산 막의 BSA 단백질 결합용량은 약 22 mg/mL이었으며, 친화 키틴 막의 lysozyme 효소 결합용량은 약 26 mg/mL로서 이는 키토산 또는 키틴을 기반으로 하여 제조된 hydrogel bead의 단백질 결합용량보다 수~수십 배 큰 값으로서, 향후 막여과 크로마토그래피용 친화 막으로의 효과적인 활용이 기대된다.

키토산 필름은 농업, 식품과 제약 분야에서 응용이 가능하다. 그러나 키토산으로만 만들어진 필름은 기체투과성이 높고 기계적 물성에 약하다. 따라서 본 연구에서는 기체 투과성을 낮추고 기계적 물성을 높이기 위해 층상구조를 갖는 점토광물의 일종인 montorillonite (MMT)와 양이온 생체고분자인 키토산을 이용하여 양이온 교환과 수소결합과정을 통해 Na+-MMT에 키토산을 삽입하여 키토산/Clay 나노복합재료를 제조하였다. 키토산/clay 나노 복합재료의 X-ray 회절패턴에서 2θ=7.5º에서 MMT의 basal reflection이 나타났고, 2θ=3~5º 주위에서의 새로운 약하고 넓은 peak로서 더 낮은 각에서 MMT의 basal reflection의 이동에 의해 삽입된 나노 구조의 형성을 증명하였다. 또한 TGA thermogram를 이용하여 clay의 함유량이 증가할수록 제조된 나노복합재료의 열분해가 일어나는 범위의 질량감소가 줄어드는 것을 확인하므로서 내열성을 관찰하였다. 기계적 물성 성질을 측정하여 clay 함유량의 증가에 따른 인장 강도와 인장 모듈러스의 변화를 관찰하고, 키토산이 층상 실리케이트 내에 삽입하여 제조된 나노복합재료에서 clay의 함유량이 증가할수록 질소 투과경로의 tortuosity를 증가시켜서 기체 투과도를 감소시키는 것도 확인하였다.

This study was peformed to investigate effect of feeding experimental mixture containing chitosan, hibiscus extract and L-carnitine on body weight and lipid metabolism in rats. Forty-eight male rats(Charles River CD) of eight weeks old and weighing 336.5±2.3g were raised for five weeks with high fat diet(40% fat as calorie) to induce obesity. After induction of obesity, rats weighing 560.4±5.6g were blocked into four groups according to body weight and raised for eight weeks with diet containing either 0.09%(+1D group), 0.9%(+10D group) or 4.5%(+50D group) of experimental mixture. Aspartate aminotransferase(AST) and alanine aminotransferase(ALT), total protein and albumin were normal levels in plasma. Body weight gain and epididymal fat pad weight were lower in experimental mixture groups than control group However, weights of perirenal fat pad and brown adipose tissue were not significantly different among all groups. There was no significant difference in plasma and hepatic lipid levels among all groups. Liver citrate lyase and camitine acyltransferase activities were not significantly different among all groups, however, citrate lyase activity was tended to be decreased with increasing experimental mixture level in diet. Fecal total lipid and total cholesterol excretions were highest in +50D group, and triglyceride excretion was highest in +1D group. in conclusion, intake of experimental mixture containing chitosan, hibiscus extract and L-camitine was effective in reducing body weight and body fat, and its inhibitory effects might lead to obesity improvement.