• Membrane and Water Treatment
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• 제9권2호
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• pp.105-113
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• 2018

Maillard reaction products like melanoidins present in industrial fermentation wastewaters are complex compounds with various functional properties. In this work, novel ultrafiltration (UF) mixed matrix membrane (MMM) composed of polysulfone (PSF) and nanocomposites was prepared through a phase inversion process for the recovery of melanoidins. Nanocomposites were prepared with acid functionalized multiwalled carbon nanotubes (MWCNTs) as the reinforcing filler for chitosan-thermoplastic starch blend. Higher nanocomposites content in the PSF matrix reduced the membrane permeability and melanoidins retention indicating tighter membrane with surface defects. The membrane surface defects could be sealed with dilute polyvinyl alcohol (PVA) solution. The best performing membrane (1% nanocomposites in 18% PSF membrane sealed with 0.25% PVA coating) resulted in uniform melanoidins retention of 98% and permeability of 3.6 L/m2 h bar over a period of 8h. This demonstrates a low fouling PSF membrane for high melanoidins recovery.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.450-450
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• 2003

• 멤브레인
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• 제8권1호
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• pp.50-58
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• 1998

Polysulfone 재질의 다공성 평판막 및 실관막에 키토산 피막층을 형성시킨 후 반응성 염료인 Cibacron Blue 3GA를 고정화시켜 human serum albumin(HSA)의 결합용량이 최대 70 $\mu{g/cm}^2$인 단백질 친화성 막을 제조하였다. 친화성 평판막 모듈을 대상으로 HSA에 대한 용출 크로마토그래피 실험을 수행하여 eluent 용액의 최적 환경조건을 결정하였는바, 1M KCl이 첨가된 농도 0.06 M, pH 10의 universal buffer를 eluent로 사용했을 때 리간드와 결합된 단백질의 용출이 가장 우수하였다. 친화성 평판막 및 실관막 모듈을 대상으로 HSA의 전열 크로마토그래피 실험을 수행하여 단백질에 대한 동적 결합용량을 측정하였다. 이 결과 동적 결합용량은 평판막 모듈의 경우에는 loading 용액의 유량과 HSA의 농도가 증가함에 따라 평형 결합용량 값으로부터 크게 감소하였으나, 실관막 모듈의 경우에는 loading 용액의 유량과 HSA의 농도에 관계없이 항상 평형 결합용량 수준을 유지하였는바, 따라서 실관막 모듈이 평판막 모듈보다 단백질 친화성 크로마토그래피 분리관으로서 더 효과적이었다.

• 한국식품영양과학회지
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• 제34권7호
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• pp.968-972
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• 2005

기능성 식품소재로서 이미 많이 알려진 키토산이 신장과 관련하여 식품이나 의료용 소재로서 활용이 가능한 지를 알아보기 위하여 신장 기능과 민감하게 관련이 있는 효소인 RDPase, Udpase의 활성을 체내$\cdot$체외 실험을 통하여 관찰하였다. 체외 실험에서 글리세롤에 의해 유도된 RDPase의 유리$\cdot$활성 감소를 다시 회복시키는 것을 관찰하였다. 체내실험에서 글리세롤 투여에 의하여 손상된 신장의 근위세뇨관에서 급격히 증가한 RDPase의 활성을 키토산이 확실하게 감소시키는 것을 관찰할 수 있었다. 키토산을 공급한 쥐의 소변에서의 Udpase의 활성이 증가하는 것을 관찰하였다.

• Journal of Pharmaceutical Investigation
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• 제28권2호
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• pp.87-92
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• 1998

Kojic acid (KA) is an antimelanogenic agent which has been widely used in cosmetics to whiten the skin color. However, it has the drawbacks of the skin irritancy and the instability against the pH, temperature, and light. In order to overcome these problems, various topical gels and multiple emulsion creams which can control the release of active ingredient, KA, were formulated employing cream bases of mineral oil with caprylic capric triglyceride and hydrophilic polymers such as chitosan, carbopol. and pluronics. Using Franz diffusion cells mounted with a synthetic cellulose membrane (MWCO 12,000), drug release characteristics of the formulations were evaluated by the HPLC assay of KA concentration in the receptor compartment of pH 7.4 phosphate buffered saline solution. Drug release from chitosan-based gels (ChitoGel) obeyed to the first order kinetics with a rapid release especially in the initial period. However, pluronic-based gels (PluGel) and carbopol-based gels (CarboGel) revealed controlled release of drug to some extent, followed by the square root-time kinetics. Moreover, the release of KA was further controlled with the W/O/W multiple emulsion creams (MultiCream), showing the apparent zero order release kinetics by virtue of dynamic ratecontrolling membrane of the oil layer. The flux $(J,\;{\mu}g/cm^2/hr)$ of ChitoGel. CarboGel. PluGel. and MultiCream in the initial period of 6hr were 73.30, 28.67. 24.04 and 7.72, respectively. On the other hand, the skin irritancy score of ChitoGel and MultiCream were observed as 2.5 and 2.3 respectively, in the rabbit skin irritation test. Although there were insignificant differences at p<0.05 between those formulations, it was possible to conclude that the W/O/W multiple emulsion creams containing KA might be a good candidate for an antimelanogenic drug delivery system due to the controlled release of acidic drug molecules.

• Archives of Plastic Surgery
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• 제49권2호
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• pp.258-265
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• 2022

Background Chitosan (CS) is a well-known antimicrobial dressing material. Moreover, widely used amniotic membranes contain growth factors beneficial for wound healing. Herein, we created a novel amnion-conjugated CS-alginate membrane dressing and tested its wound healing potency in a diabetic swine model. Methods The bovine amniotic powder growth factor contents were evaluated by protein assay, and the powder's wound healing effects were assessed in vitro by HaCaT cell scratch closure. In vivo, two minipigs developed streptozotocin-induced diabetes. Serial serum glucose measurements and intravenous glucose tolerance tests were performed to confirm their diabetic status. Twelve square-shaped wounds created on each pig's back were randomly divided into control (n = 4), CS (n = 4), and amnion-CS (AC; n = 4) groups and treated accordingly with different dressings. Wound healing in each group was assessed by measuring wound contraction over time, capturing wound perfusion with indocyanine green (ICG) angiography, and histologically analyzing inflammatory markers. Results Amniotic powder elution promoted HaCaT cell migration in the scratch wound model, suggesting its beneficial in vitro wound healing effects. In vivo, the CS and AC groups showed earlier wound contraction initiation and reepithelialization and earlier wound perfusion improvement by ICG angiography than the control group. Additionally, the wound size of the AC group at week 3 was significantly smaller than those in the control group. There was no significant difference in the numbers of acute and chronic inflammatory cells between the groups. Conclusion The amnion-conjugated CS-alginate membrane, as well as CS dressing alone, could be a favorable dressing option for diabetic wounds.

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 The 4th Korea-Italy Workshop
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• pp.61-64
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• 2003

Optical resolution of a-amino acid (tryptophan and tyrosine) optical isomers was achieved by a pressure driven membrane separation process, using self-supporting crosslinked membranes base on polysaccharide with different swelling indices that ranged from 100 to 70%. The membranes prepared by casting and drying the polymer solution containing 5wt% acetic acid on an acryl plate followed by crosslinking with glutaraldehyde were characterized using such analytical methods as FTIR and swelling index measurements. On the way of separating the optical isomers, several experimental factors such as the concentration of the feed solutions, operating pressure and temperature, and degree of crosslinking of the membranes have been studied. When the chitosan membranes with 70% of swelling index were used , almost complete optical resolution was obtained; 97.92% of enantiomeric excess (ee %) and 2.26 g/$m^2$ㆍh of flux. The operating pressure and the concentration of feed solutions were respectively 1.0 kgf/$\textrm{cm}^2$ and 0.49 mmol/L.

• 멤브레인
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• 제11권1호
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• pp.22-28
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• 2001

이온성 고분자에 비이온성 고분자를 섞어 이온 함량을 조절함으로써 다양한 전하량을 갖는 이온성 막을 제조하였다. 비이온성 고분자로는 폴리비닐알콜, 음이온성 고분자로는 알긴산 나트륨, 양이온성 고분자로는 키토산을 사용하였으며, 이들 이온성 고분자막을 사용하여 여러 전해질 수용액에 대한 투과 및 분리특성을 관찰하였다. 막 내부에 이온성 고분자 함량이 많을수록 친수성 특성을 보였으며, 순수투과 및 용액투과 속도가 증가함을 관찰할 수 있었고, 또한 투과속도는 막의 팽윤 거동에 의해 결정됨을 확인할 수 있었다. 용질 배제율의 경우는 막과 투과용질간의 정전기적 인력, 즉 Donnan exclusion에 의해 결정이 되며, 정전기적 인력이 비슷한 경우는 분자체 효과에 의해 분리됨이 관찰되었다.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.2042-2045
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• 2007

The effect of chitosan oligosaccharide (COS, 1 kDa${\gamma}$, 10 ng/ml IL-$1{\alpha}$, and 25 ng/ml TNF-${\alpha}$) in HT-29 cells. Inducible nitric oxide synthase (iNOS) expression induced by these cytokines was inhibited by COS. COS pretreatment inhibited the invasiveness of cytokines-treated HT-29 cells through Matrigel-coated membrane in a dose-dependent manner. COS also inhibited cytokines-induced matrix metalloproteinase (MMP)-2 activity. This study shows that proinflammatory cytokines induce NO production, iNOS expression, and invasiveness of human colorectal adenocarcinoma HT-29 cells. COS pretreatment inhibited cytokines-mediated NO production, iNOS expression, and invasiveness of HT-29 cells. These results provide sufficient information for the further development of COS as an antitumor metastatic agent for the treatment of colon cancer.

• 한국응용과학기술학회지
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• 제17권1호
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• pp.43-48
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• 2000

Drug delivery system(DDS) applied to various fields, such as medicine, cosmetics, agriculture and necessities of life. Among these application fields, DDS is often used as the method of drug dosage into the epidermic skin. We investigated characters of transdermal therapeutic system(TTS) and the skin permeability of that with applying DDS. Chitosan was selected as material of TTS. We investigated the permeation of chitosan ointment containing drug in rat skin using horizontal membrane cell model. Permeation properties of materials were investigated for water-soluble drug such as riboflavin in vitro. We used glycerin, PEG 600 and oleic acid as enhancers. Since dermis has more content water(hydration) than the stratum corneum, skin permeation rate at steady state was highly influenced when glycerin was used in water-soluble drug. The permeation rate of content enhancer and drug was found to be faster than that of content water-soluble drug only. These results showed that skin permeation rate of drug across the composite was manly dependent on the property of ointment base and drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate.