• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.65-66
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• 1996

투과증발법은 상부에 액체공급액이 반투과막과 접촉하고 있고 하부에 진공에 가까운 낮은 압력을 걸어줌으로써 투과물이 수증기로 제거되는 막공정의 하나이다. 막을 통한 분리는 혼합물의 각 성분이 막내에서 다른 용해도와 확산도를 가지고 있기 때문에 발생한다. 이 공정의 지배적인 전달 메카니즘은 용해-확산 모델을 기초로 하고 있기 때문에 전형적으로 투과증발막은 대개 미세다공성 지지체에 얇은 선택성을 가진 재료를 입힌 복합막을 사용한다. 본 연구의 목적은 선택성을 가진 상부층막이 키토산인 복합막에서 지지체 구조의 영향을 살펴보고 키토산 복합막에 대한 물-에탄올 분리에 대해 최적의 모델을 찾는 것이다. 투과증발막소재로서의 키토산은 친수성기를 가지고 있으므로 물과 알코올의 분리에서 물만을 선택적으로 흡수하여 투과시키는 우수한 성능을 지니고 있으나 더욱 효과적인 막성능을 발휘하기 위해서는 지지체의 역할 및 막성능에 영향을 끼치는 여러 가지 인자들을 고려해서 막을 설계하는 것이 필요하다. 여기서는 상부층의 막두께, 지지체의 특성, 피드 농도 등을 변화시켜 가장 적당한 모델을 예측하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권5호
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• pp.345-349
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• 2000

To easily separate chitosanoligosaccharides by size exclusion, an coencapsulating technology of substrate and enzyme was developed. The membrane was composed of alginate and a divalent cation such as calcium. Chitosan and chitosanase were enveloped in this membrane and the product released to medium by size exclusion. The capsule was stabilized in a 2% acetic acid solution (pH 5.0) containing 0.145 M CaCO$_3$. The leakage of substrate caused by the agitation speed was controlled by increasing alginate and CaCO$_3$concentrations. The lower limit of the alginate concentration and the agitation speed were 0.5% and 49rpm, respectively. Membrane thickness and capsule diameter were 10$\mu\textrm{m}$ and 2.5mm, respectively. By TLC analysis, the composition of chitosanoligosaccharides were mainly 3-6 mers. The molecular weight distribution of the released oligosaccharides ranged from 262 to 3624 Da by GPC.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 춘계 총회 및 학술발표회
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• pp.124-126
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• 1998

1. INTRODUCTION : With good physical and chemical properties as a membrane material, poly(vinyl alcohol) (PVA) has been widely used for the preparation of several kinds of membranes for different applications. Considering such good physical chemical properties, some people have tried to use it for the formation of reverse osmosis (RO) membranes with a good chemical stability as well as high flux and high rejection rate. However, unfortunately, the performance of the RO membranes based on PVA has not been satisfactory yet. The PVA RO membranes thermally crosslinked have shown very low flux and relatively low salt rejection. In this experiment, ionic polymers such as sodium alginate and chitosan were used together with PVA to increase the nanofiltration performance of the PVA membranes.

• Journal of Periodontal and Implant Science
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• 제33권3호
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• pp.457-474
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• 2003

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

• 한국식품과학회지
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• 제32권1호
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• pp.218-224
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• 2000

분자량이 상이한 세 종류의 키토산의 항균활성을 E. coli O157 : H7, S. aureus 및 C. albicans 균주를 이용하여 측정, 분석하였다. E. coli O157 : H7와 S. aureus에 대해서는 분자량 10,000인 키토산이 가장 강한 항균활성을 보였으며 C. albicans에 대해서는 6량체의 키토산 올리고당이 가장 강한 활성을 나타내었다. 키토산 첨가농도는 E. coil O157 : H7와 S. aureus의 경우 0.1 mg/mL의 농도에서, C. albicans의 경우는 chitohexaose 1 mg/mL의 농도에서 항균활성이 가장 높았다. 모든 키토산 처리구에서 미생물 사멸 속도는 키토산 처리 1시간 이내에서 가장 높게 나타났으며 그 이후로는 점차 낮은 속도를 보였다. 사멸되었거나 파손된 미생물 세포로부터 유래되는 단백질, 핵산물질 및 $Ca^{2+}$ 량은 키토산 처리 시간 이내에 가장 많았으며 ${\beta}-galactosidase$ 활성도 같은 시간대에서 가장 빠른 속도로 중대되는 것으로 나타났다. S. aureus에 대한 세포막 손상 정도를 측정하여 본 결과 전체 미생물균체중 약 10%에 상당하는 균수가 막손상을 가져 왔다. 따라서, 키토산은 고유의 양이온성 성질을 이용하여 미생물의 세포벽과 세포막에 결합하여 그 결과로 세포 내 물질의 세포 외로의 유출내지는 세포막 대사의 저해 등의 효과를 나타냄으로써 항균활성을 나타내는 것으로 추측되었다.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.526-536
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• 2015

Leptospirosis is a worldwide zoonotic disease caused by pathogenic Leptospira, a genus of which more than 250 serovars have been identified. Commercial bacterin vaccines are limited in that they lack both cross-protection against heterologous serovars and long-term protection. This study investigated in mice the immunogenicity of an anti-leptospirosis vaccine, using the outer membrane proteins LipL32 and Loa22 as antigens. The immunogenicity of this vaccine formulation was compared with those induced by vaccines based on LipL32 or Loa22 alone. A DNA-encapsulated chitosan nanoparticle was used for in vivo DNA delivery. Using a unique DNA plasmid expressing both lipL32 and loa22 for vaccination, higher antibody responses were induced than when combining plasmids harboring each gene separately. Therefore, this formulation was used to test the immunogenicity when administered by a heterologous prime (DNA)-boost (protein) immunization regimen. The specific antibody responses against LipL32 (total IgG and IgG1) and Loa22 (IgG1) were higher in mice receiving two antigens in combination than in those vaccinated with a single antigen alone. Although no significant difference in splenic CD4⁺ T cell proliferation was observed among all groups of vaccinated mice, splenocytes from mice vaccinated with two antigens exhibited higher interferon-γ and IL-2 production than when using single antigens alone upon in vitro restimulation. Taken together, the immunogenicity induced by LipL32 and Loa22 antigens in a heterologous primeboost immunization regimen using chitosan as a DNA delivery system induces higher immune response, and may be useful for developing a better vaccine for leptospirosis.

• 대한환경공학회지
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• 제34권6호
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• pp.406-413
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• 2012

막오염을 감소시킬 수 있는 첨가제로서 chitosan, 염화제이철, MPE50의 막오염 저감 효과를 비교하여 연구하였다. 세가지 첨가제를 다양한 농도로 활성슬러지에 주입한 후 회분여과실험을 수행하여 막오염 특성의 변화를 평가하였다. Chitosan 20 mg/g-MLSS, 염화제이철 70 mg/g-MLSS, MPE50 20 mg/g-MLSS의 주입량에서 여과저항과 케이크 비저항이 모두 최소화되었는데, 케이크 여과저항 뿐 아니라 파울링 여과저항도 함께 감소하는 양상이 관찰되었다. 그러나 서로 다른 활성슬러지에 chitosan을 첨가하는 세 차례의 실험에서 최적 주입농도는 10, 20, 30 mg/g-MLSS로 서로 다르게 나타나, 최적 주입농도가 상수치가 아니라 활성슬러지의 특성에 영향을 받는 것으로 확인되었다. 세 첨가제 모두 최적 주입농도보다 더 많은 양을 주입한 경우 오히려 막여과 특성이 악화되었다. 첨가제의 주입에 따른 여과저항 감소의 기작을 분석하기 위하여 미생물 플록의 제타 전위, 소수성, 입도분포, 상징수 탁도, 용존성 EPS 등의 다양한 분석을 수행하였다. 최적 주입농도에서 제타전위는 0에 가깝게 그리고 입자크기는 가장 크게 나타났는데, 이러한 결과는 음전하를 띠는 슬러지 플록에 양전하의 첨가제가 주입되면서 미세입자의 불안정화 및 재안정화 메커니즘을 보이는 것으로 해석할 수 있다. 또한 최적 주입농도에서 용존성 EPS 농도와 상징수 탁도는 가장 작은 값이 관찰되었는데, 미생물 플록이 응집하며 성장하는 과정에서 고분자의 EPS와 미세 입자가 포집된 결과로 해석된다. 또한 이러한 효과는 고분자성 양이온물질인 chitosan과 MPE50에서 염화철보다 더 크게 나타났다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.411-412
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• 2007

See Full Text

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.465-478
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• 2007

Various periodontal barrier membranes used in many clinical and experimental fields, and many recent studies of membranes have reported good results. To improve clinical results, selection of barrier membranes is an important factor. So, we need not only to evaluate various barrier mem-branes, but also to understand the property of barrier membranes appropriate to defect characteristics. For this purpose, this study reviewed available literature, evaluated comparable experimental models, and compared various barrier membranes. From above mentioned methods, the following conclusions are deduced. 1. In i-wall periodontal defect models, new bone formation showed a consistent result, almost 30% of the defect size. New cementum formations measured mostly 40% of the defect size, but showed more variations than new bone formations. This seems to be resulted form difference in experimental methods, so standardization in experimental methods is needed for future studies. 2. Application PLGA barrier membrane to periodontal defect demonstrated improved healing in new bone and new cementum. 3. There was a minimal periodontal regeneration with calcium sulfate barrier membrane only. But, there was better healing pattern in combination of calcium sulfate membrane with bone graft material, such as DFDBA, 4. There was no significant difference between the experimental group that used chitosan mem-brane only and the control group. But, in combination with bone graft material for space maintanence, periodontal regeneration was improved. Overall, Space maintenance is a critical factor for Guided tissue regeneration using barrier membranes. Also, a barrier membrane itself that has difficulty in maintaining space, achieved better result when used with graft material.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.60-61
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• 1996

Polyanion-polycation complexes had been known for a long time on an empirical basis fromthe mutual precipitation of proteins, before Kossel at the end of the previous century recognized the electrostatic nature of the interaction between oppositely charged polyions. The formation of polyelectmlyte complexes is essentially a result of the electrostatic nature of the interaction between oppositely charged polyions. This interaction in the macroscopic homogeneous system the phase transition by polysalt precipitation as well as the chemical and physical structure of polyelectrolyte complex membranes have been intensively investigated from the themodynamical and kinetical point of view.