• Biotechnology and Bioprocess Engineering:BBE
• /
• 제2권2호
• /
• pp.97-100
• /
• 1997

Cyclodxtrin homologues(CDs), produced by cyclodextrin glycosyltransferase(CGTase), were simultaneously partitioned in aqueous two-phase system(ATPS). Partition coefficients of CDs were measured in PEG/dextran systems. Phosphate, citrate, sulfate were tested as salt. ATPS of PEG/salt and PEG/dextran had the partition coefficients of the CDs, larger than unity. However, PEG/dextran system was observed better than PEG/salt as CGTase activity decreased sharply with salt concentration. Enzymatic rection occurred mainly in PEG-rich bottom phase because of the low partition coefficient of CGTase. The resulting CDs transferred to the PEG-rich top phase, obeying the diffusional partition. In the ATPS of 7% PEG(M.W.40, 000), 7mg/ml of CDs were obtained in top phase at 4.5 hours.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 가을 학술발표회 논문집
• /
• pp.257-258
• /
• 2003

Crafting process consists of the reversible protection of the hydroxyl groups of the polysaccharide backbone by silylation, followed by the ring-opening polymerization (ROP) of $\varepsilon$-caprolactone (CL) initiated by the free remaining hydroxyl groups of the partially silylated dextran in the presence of tin-based catalysts. The last step relies upon the removal of silylating groups under mild acidic conditions yielding the desired amphiphilic graft copolymers.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.107-107
• /
• 2013

Many nanomaterials are being harnessed as critical components in various systems for biomedical applications including diagnosis, imaging, and drug delivery. Those systems necessitate biocompatibility and low toxcity within effective dose range while achieving enough efficacy. Even though many nanomaterials enjoy successful demonstrations in bioapplications, lack of biocompatibility and high cytotoxicity often become hurdles for practical bioapplications. On the other hand, it is important to achieve enough efficiency based on chemically well-defined systems with efforts to understand mechanism at molecular level. Here, we developvarious biocompatible nanomaterials based on simple procedure using dextran as both reducing agent and surface coating. Dextran is one of the popular biocompatible polymers that have been used for drug delivery and biosensors. Dextran coated nanomaterials showed excellent colloidal stability, flexible surface chemistry for conjugation of bioactive molecules and low cytotoxicity with successful demonstrations in various bioapplications.

• Journal of Microbiology and Biotechnology
• /
• 제9권5호
• /
• pp.589-592
• /
• 1999

Suspension cultures of Digitalis lanata were successfully performed in an aqueous two-phase system (ATPS) of 4.5％ polyethylene glycol (PEG) 20,000 and 2.8％ crude dextran. Cell growth in the medium containing an individual ATPS-forming polymer was inhibited due to the toxicity of PEG and a high viscosity of dextran. Formation of ATPS supported cell growth by showing a considerably decrease in viscosity and partitioning of cells into a PEG-lean dextran phase. It was found that an aqueous two-phase cultivation of plant cells in a stirred tank bioreactor could be successfully applied.

• 한국식품저장유통학회지
• /
• 제23권5호
• /
• pp.718-726
• /
• 2016

단호박 분말을 이용하여 식물성 젖산균의 발효 최적화를 통한 점질물 dextran, 만니톨을 생산함으로서 물성과 맛이 개선된 푸딩형태의 단호박 젖산 발효물을 제조하였다. 단호박 농도에 따라서 젖산 발효물에 영향을 주었으며, 단호박 분말 15% 조건이 가장 양호한 물리화학적 특성을 보였다. $25^{\circ}C$에서 3일 동안 발효를 수행하였을 때 15% 단호박 분말의 젖산 발효물의 pH, 산도는 각각 3.85, 1.30%이었으며, 생균수는 $4.64{\times}10^9CFU/mL$로 높은 값을 나타내었다. 단호박 분말 paste의 발효 초기에 L값 25.02, a값 4.66, b값 13.35를 나타내었으며, 발효가 진행되면서 L값을 제외하고 감소하는 경향을 보였다. 10%, 15% 단호박 분말의 발효물은 발효 1일에 설탕의 소진율 100%를 보였으며, 발효 3일에 불용성 dextran을 각각 5.6%, 8.9%를 보였으며, 수용성 dextran은 4.5% 수준으로 유사하였다. 15% 단호박 분말의 3일 후에 발효물에 과당과 만니톨 함량은 각각 1.76%, 3.11%를 나타내었다. 15% 단호박 젖산 발효물의 점조도는 초기 $48.6Pa{\cdot}s^n$로서 가장 높은 값을 보였으며, 발효 1일 $75.1Pa{\cdot}s^n$에로 증가하였으며, 발효 3일에는 $188.8Pa{\cdot}s^n$으로 크게 증가하면서 푸딩 형태의 물성을 나타내었다. 단호박 젖산 발효물의 관능평가를 통해서 15% 단호박 젖산 발효물이 색, 단맛, 조직감에서 높은 점수로 평가되었다. 결론적으로 15% 단호박 분말과 20% 설탕혼합액을 이용하여 3일 동안 젖산 발효시킴으로서 설탕은 100% 전환되었으며, protiotic 생균 $4.6{\times}10^9CFU/mL$을 포함한 만니톨, 점질물 dextran의 생성을 통해서 기능성, 맛과 조직감이 강화된 푸딩형태의 단호박 젖산발효제품을 개발할 수 있었다.

• KSBB Journal
• /
• 제5권4호
• /
• pp.377-382
• /
• 1990

The characteristics controlled drug release have been studied for biodegradable polymer matrix. Polymer matrix was prepared from glycerine, prednisolone and dextran. Mathematical analysis of the data showed that the release behavior actually conformed to the Higuchi's diffusion controlled model. The release time was increased as drug loading doses increased, whereas decreased as glycerine concentration increased. The release rate did not change by varying molecular weight of dextran.

• 대한한방내과학회지
• /
• 제33권4호
• /
• pp.520-532
• /
• 2012

Objectives : This study was carried out to investigate the effects of Coicis Semen Extract (CSE) on the experimental colitis induced by dextran sulfate sodium (DSS) in mice. Methods : Experimental colitis was induced by daily treatment with 5% DSS in the drinking water for 7 days in 6-week-old male ICR mice. The colitic mice were divided into three groups: the normal (N) group consisted of mice that were not inflammation-induced. The control (C) group was composed of untreated colitis elicited mice. The sample (S) group was administered CSE after colitis elicitation. The effects on colonic mucosal ulcers were evaluated by the morphological, histological and immunohistochemical change of the large intestine. Results : Inhibition of LPS-induced NO decreased in the S group. Inhibition of LPS-induced iNOS and COX-2 mRNA noticeably decreased in the S group from 0.25 mg/ml. In the common morphological and histochemical change, the erosion and the infiltration of inflammatory cells increased in the C group, while they noticeably decreased in the S group. The length of colon was shortened more in the C group than in the S group. The distributions of MUC2 and Hsp70 treated with CSE increased noticeably more in the S group than in the C group (p<0.05). It was confirmed histochemically and immunohistochemically that the distributions of iNOS, COX-2, MAC387, serotonin, apoptosis and PCNA treated with CSE decreased in the S group more than in the C group (p<0.05). Conclusions : It is confirmed that CSE has cytoprotective effect, so can alleviate inflammation process. Therefore, it is expected to have potential protective effect on colitis.

• Journal of Microbiology and Biotechnology
• /
• 제18권9호
• /
• pp.1599-1605
• /
• 2008

Biodistribution and lymphoscintigraphy of cyclosporine A (CyA) and technetium-99m ($^{99m}Tc$) were studied using ${^99m}Tc$-labeled dextran acetate (DxA) including CyA. DxA particles were prepared from dextran with acetic anhydride, and CyA was loaded into them. Lymphatic delivery of ${^99m}Tc$-labeled DxA particles containing CyA was evaluated after subcutaneous injection into the foot pad of rats and compared with those of ${^99m}Tc$-labeled human serum albumin (HSA). The labeling efficiency of CyA-loaded ${^99m}Tc$-DxA particles was about 95% at 30 min. The labeling efficiency maintained stably above 80% for 12 h. The percent injected dose (%ID) of CyA-loaded ${^99m}Tc$-DxA was similar to that of ${^99m}Tc$-HSA at the inguinal lymph node after 40 min. The CyA-loaded ${^99m}Tc$-DxA could be as well distributed as ${^99m}Tc$-HSA through the lymph node. The DxA particles could steadily distribute the CyA as well as the ${^99m}Tc$ radiolabeling through the lymph node.

• 대한한방소아과학회지
• /
• 제29권3호
• /
• pp.54-64
• /
• 2015

Objectives : This study was to investigate the anti-oxidative and anti-inflammatory effect of Lonicera japonica water extracts (LE) on Ulcerative Colitis Induced by DSS (Dextran Sulfate Sodium) in Mice. Methods : Colitis was induced by DSS in Balb/c mice. The sample group was divided into three. The mice in control group were not inflammation-induced. The pathological group was composed of untreated colitis elicited mice. The experimental group was administered Lonicera japonica water extracts (LE) after colitis elicitation. The effects on ulcerative colitis were evaluated the anti-oxidant effect, inhibition of COX-2 mRNA expression, the morphological change of colonic mucosa, decrease effect of HSP 70 and COX-2 in mucosa. Results : The SOD ability of LE was dose-dependently increased and the LPS-induced COX-2 mRNA expression of LE was dose-dependently decreased. LE showed the protective effects on DSS-induced experimental colitis. LE inhibited shortening of colon length, the hemorrhagic erosion in colonic mucosa. LE also showed the decrease effect for HSP70 and COX-2 in mucosa. Conclusions : The current results demonstrate the clinical utility of LE in traditional medicine and indicate the possible treatments for ulcerative colitis from natural products. Further investigations for exact mechanisms will be needed.

• 대한한방내과학회지
• /
• 제34권2호
• /
• pp.134-146
• /
• 2013

Objectives : Auklandia Lappa (ALE) is one of the herbs used frequently to treat abdominal pain and diarrhea and reported anti-inflammatory activity by suppressing proinflammatory cytokines. This study was designed to investigate whether ALE could show protective activities on experimental colitis induced by dextran sulfate sodium (DSS) models. Methods : Colitis was induced by DSS in Balb/c mice. ALE 10, 30, 100 and 300 mg/kg were orally administered twice a day for 7 days in DSS model. Mice weight was measured daily. Scoring of clinical findings was measured every other day. Colon length, edema, fecal blood and histological damages were assessed at day 7 in DSS model. In histological analysis, we checked cryptal glands, surface epithelium, submucosa, transmural, stroma and scored degree of inflammatory cell damage by modified histological scoring. We also calculated cytokines concentrations including IFN-${\gamma}$, TNF-${\alpha}$, IL-6, IL-$1{\beta}$, IL-17, IL-23, IL-10 and TGF-${\beta}1$ by Biometric Multiplex Cytokine Profiling method. Results : ALE showed the protective effects on DSS-induced experimental colitis. ALE inhibited shortening of colon length and histological damages of colon does-dependently, but it did not inhibit weight loss. ALE also inhibited IFN-${\gamma}$ and IL-6 expression, and upregulated cytokines (IL-10, TGF-${\beta}1$) related to regulatory T cell differentiation and proliferation. Conclusions : The current results demonstrate the clinical utility of ALE in traditional medicine and indicate the possibility of potent drug development of inflammatory bowel diseases from natural products. Further investigations for exact mechanisms will be needed.