• Journal of Pharmaceutical Investigation
• /
• 제31권2호
• /
• pp.101-106
• /
• 2001

Alginate-chitosan (anion-cationic polymeric complex) was prepared to control the release rate of silver sulfadiazine (AgSD). Na-alginate (2%) solution containing AgSD was gelled in $CaCl_2$ solution. The gel beads formed were immediately encapsulated with chitosan (CS). The gel matrix and membrane were then reinforced with chondroitin-6-sulfate (Ch6S). Release rate of AgSD from the gel matrix was investigated by placing alginate beads in the sac of cellulose membrane simmered in HEPES-buffer solution. The concentration of AgSD released was analyzed by UV at 264 nm. Incorporation capacity of AgSD in Ca-alginate gel was more than 90%. Alginate-Ch6S-CS could control the release rate of AgSD. The amount of AgSD release was dependent on the AgSD loading dose. Incorporation of tripolyphosphate (polyanionic crosslinker) onto the alginate-Ch6S-CS bead increased the release rate of AgSD. Collagen-coating had no influence on the AgSD release rate. Alginate-Ch6S-CS beads with a sufficiently high AgSD encapsulation were capable of controlling the release of the drug over 10 days. In summary, alginate-Ch6S-CS beads could be used as a sustained delivery for AgSD and provide local targeting with low silver toxicity and patient discomfort.

• Bulletin of the Korean Chemical Society
• /
• 제34권5호
• /
• pp.1333-1338
• /
• 2013

Chitosan-based nanoparticles (CSNP) were prepared through ionic cross-linking and gelation of chitosan (CS) by tripolyphosphate (TPP). CS properties such as molecular weight, and preparation conditions were screened and the resulting nanoparticles were examined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained particles were consistently spherical with an overall diameter of approximately $107{\pm}20$ nm. They were successfully used as a carrier for Zidovudine, an anti-human immunodeficiency virus (HIV) which, to our knowledge, is novel. The encapsulation ability, loading capacity, and controlled release behavior for these CSNP was evaluated. Results indicated that their intrinsic properties were strongly affected by properties inherent to CS such as molecular weight, and by the preparation condition, such as cross-linking density, which depends on the concentration of the cross-linker. In vitro release tests for the entrapped zidovudine showed that the CNNP provided a continuous release that can last upwards 20 h.

• 폴리머
• /
• 제36권2호
• /
• pp.149-154
• /
• 2012

생체적합성을 가진 키토산과 강력한 항산화제로 알려진 리포산을 합성하여 만든 양친매성 고분자를 이용하여 약물전달시스템으로서의 응용 가능성을 알아보았다. 수용액 상에서 자기조립의 성질을 가지는 양친매성 고분자는 나노입자를 형성하고 이 입자 안에 항암제로 널리 쓰이는 5-fluorouracil을 고체분산법을 이용하여 봉입하였다. 최적의 약물전달체를 얻기 위하여 키토산에 결합된 리포산의 비율을 조절하여 입자크기 및 약물봉입률을 비교하였다. DLS를 이용하여 측정한 나노입자는 약 250 nm 정도의 크기를 가졌고 그 봉입률은 10% 내외로 측정되었다. 42%의 리포산 치환율을 가지는 공중합체가 약물전달체로서 가장 우수한 성능을 보여주었다.

• Preventive Nutrition and Food Science
• /
• 제21권2호
• /
• pp.85-89
• /
• 2016

Omega-3 rich fish oils are extremely labile, thus requiring control of oxidation and off flavor development. A recently proposed emulsification method, layer-by-layer (LbL) deposition, was found to be a plausible method to enhance the characteristics of bioactive ingredients, especially lipids. The present work was designed to test the possibility of enhancing the uptake and utilization of omega-3 fatty acids present in fish oil. The bioavailability of nano-emulsified fish oil was monitored in terms of intestinal absorption as well as skin permeability by using the everted intestinal sac model and Franz cell model. The skin permeability and intestinal absorption characteristics was significantly improved by LbL emulsification with lecithin/chitosan/low methoxypectin. Multilayer encapsulation along with nano-emulsification can be a useful method to deliver biologically active lipids and related components, such as fish oil. The protective effect of this tool from lipid oxidation still needs to be verified.

• 접착 및 계면
• /
• 제9권2호
• /
• pp.8-15
• /
• 2008

마이크로캡슐은 다양한 기능성 물질의 약물 전달 시스템으로서 화장품과 제약 분야에서 널리 적용되고 있다. 키토산은 천연에 풍부하게 존재하는 생체고분자로 생체적합성이 우수하며 무독성이다. 본 연구에서는 키토산 마이크로캡슐을 글루타르알데히드를 가교제로 사용하여 W/O 형태의 유화법으로 제조하였다. 유화제로는 span80을 사용하였으며 가교가 시행되는 bath상의 물질은 mineral oil을 사용하였다. 제조된 키토산 마이크로캡슐은 완벽한 구의 형태로 평균 $2{\sim}10{\mu}m$ 크기를 보였으며, 교반속도와 유화제의 농도에 따른 캡슐의 직경 및 형태 변화를 관찰하였다. 마이크로캡슐의 방출실험을 하기 위하여 가교제, 키토산, 그리고 유화제의 양을 변화시키면서 방출 속도를 측정하였다. Riboflavin의 방출속도는 키토산의 가교 정도와 사용한 유화제의 양에 따라 크게 변하였다.

• 대한화학회지
• /
• 제57권1호
• /
• pp.88-93
• /
• 2013

In order to construct a controlled release system of drugs and to reduce toxic side effects of 5-fluorouracil, the novel ramose chitosan-based-5-fluorouracil microspheres (CS-FU-MS) were prepared. Firstly, using chitosan (CS) as carriers and 5-fluorouracil (5-FU) as a model drug, ramose chitosan-based-5-fluorouracil (CS-FU) was efciently synthesized by chemical crosslinking method through microwave irradiation, drug loading was 10.6%; Secondly, CS-FU-MS were prepared by CS-FU self-assembled under the dialysis conditions and the free 5-FU was encapsulated further at the same time. The size dispersivity of particles is uniform, and the average diameter of the CS-FU-MS was $4{\mu}m$. The drug encapsulation efficiency was 76.1%, and the drug loading was increased to 26.22%. CS-FU-MS maintain the zero-order release time in PBS (pH = 7.4) and HCl/KCl (pH = 1.2) dialysis medium was 40h and 34h respectively, and the cumulative release were 58.89% and 79.33% in 182 h. The results showed that CS-FU-MS have excellent sustained release properties.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
• /
• pp.1062-1065
• /
• 2004

The importance of display is becoming increasingly important due to the development of information and industry where it leads to diverse and abundant information in today's society. The demand and application range for FPD(Flat Panel Display), specifically represented by LCD(Liquid Crystal Display) and PDP(Plasma Display Panel), have been rapidly growing for its outstanding performance and convenience amongst many other forms of display. The current focus has been on OLED(Organic Light Emitting Diode) in the mobile form, which has just entered into mass production amid the different types of FPD. Many studies are being conducted in regards to device, vacuum evaporation, encapsulation, and drive circuits with the development of device as a matter of the utmost concern. This study develops a new type of light-emitting materials by synthesizing medical polymer organic chitosan and phosphor material CuS. Chitosan itself satisfies the Pool-Frenkel Effect, an I-V specific curve, with a thin film under $20{mu}m$, and demonstrates production possibility for a living body sensors solely with the thin film. Furthermore, it enables production possibility for EML of organic EL device(Emitting Layer) with liquid Green light emitting and Blue light emitting as a result of synthesis with phosphor material.

• Korean Chemical Engineering Research
• /
• 제48권2호
• /
• pp.178-184
• /
• 2010

본 논문에서는 생체적합성 고분자들의 자기 조립 특성을 이용하여 마이크론 단위의 캡슐을 제조하여, 캡슐 내부에 단백질을 넣고 시간과 pH에 따른 방출 거동을 고찰하였다. 본 연구에서는 키토산과 헤파린 그리고 알지네이트를 사용하여 동공(hollow) 캡슐을 제조하였다. 멜라민과 포름알데히드를 일정 비율로 혼합하여, 표면에 전하를 가지는 마이크론 단위의 core를 제조한 후, 음전하를 가지는 헤파린 혹은 알지네이트를 core 위에 흡착시키고, 양전하를 띠는 키토산을 흡착시킨 후, core 위에 교대로 흡착시켜 Multilayer를 형성시켰다. 4 층을 쌓은 후에 HCl을 이용하여 pH 2로 조절하면, core는 제거되고 속이 비어 있는 캡슐을 제조할 수 있었다. 동공 캡슐은 투과전자현미경, 표면주사현미경 및 광학현미경으로 관찰하였다. 이러한 캡슐은 pH에 따라서 각기 다른 거동을 보이는데, 본 연구에서는 내부에 FITC-albumin을 넣어 UV분광기로 방출되는 상대적인 양을 관찰한 결과, 키토산-헤파린 캡슐과 키토산-알지네이트 캡슐은 각기 다른 pH에서 개폐됨을 알 수 있었다.

• 한국식품과학회지
• /
• 제34권2호
• /
• pp.255-262
• /
• 2002

본 실험에서는 L. fermentum YL-3의 생존에 관한 연구로 살아 있는 상태로 위를 거쳐 장내에 정착하여 생균제로서의 기능을 수행할 수 있도록 내산성과 저장성에 초점을 맞추었다. 유산균 성장촉진 물질로 첨가되어 온 tween 80 성분의 제거가 pH 2.0에서 L. fermentum YL-3의 내산성을 약 1 log cycle 정도 향상시켰다. 지방산 분석에서는 세포의 유동성 및 동결 등에 저항성을 가진다고 보고되는 $C_{19:0}\;cyc\;{\omega}8c(lactobacillic\;acid)$의 성분이 24.6% 증가함으로써 내산성이 향상됨을 알 수 있었다. 온도별에서도 배양 온도가 상승할수록 내산성은 향상되었으며 배양시간 역시 길수록 향상되나 생균수를 고려해야 하므로 $42^{\circ}C$의 배양온도에서 대수기 말기의 균제를 이용하였다. 그래서 최종 배양 조건은 tween 80이 제거된 $MRS^-$ 배지에서 $20{\sim}24$시간 $42^{\circ}C$에서 혐기 배양을 실시한 균체를 capsule 제도에 이용하였다. Alginate capsule이 산, 열, 인산염 등에 풀어지는 단점을 가져 무독성의 1% chitosan을 이용하였으며 표면의 관찰 결과, chitosan처리 후 가교 결함에 의하여 더욱 촘촘한 막이 형성되었으며 alginate capsule에서 여러 군데 보이던 미세 구멍이 줄었으며 CLSM을 이용한 L. fermentum YL-3의 포집은 안정한 상태로 포집 균수는 약 $2.0{\times}10^9\;CFU/g$ 정도였다. 캡슐화된 L. fermentum YL-3의 내산성에서는, 3시간 동안 pH 2.0에서 alginate capsule은 약 40 %가 생존한 반면 chitosan 처리 후의 alginate capsule은 약 65% 정도로 생존율의 향상을 보였다. 캡슐화된 L. fermentum YL-3의 저장성에서는 상온인 $25^{\circ}C$에서는 초기 균수에서 1주 사이 $2{\sim}3\;log\;cycle$정도로 급격히 사멸되었으며 chitosan 처리구나 zeolite 처리구에 의한 상온에서의 저장성 향상에서는 영향을 미치지 못했다. $4^{\circ}C$에서는 $2.0{\times}10^9\;CFU/g$이었던 초기균수가 3주까지 모두 $10^8\;CFU/g$ 이상의 생존율을 나타내었으며 특히 chitosan으로 처리한 capsule의 저장성은 3주 후 약 24% 정도로 alginate capsule에 비해 생존율이 높았다.

• Journal of Pharmaceutical Investigation
• /
• 제41권5호
• /
• pp.279-288
• /
• 2011

The Dexamethasone (DEX) loaded chitosan microspheres were prepared by thermal denaturation and chemical cross-linking method using a dierent concentration of glutaraldehyde as chemical cross-linking agent. The prepared microspheres were evaluated for the percentage of Drug Loading (DL), Encapsulation Efficiency (EE) and surface morphology by Scanning Electron Microscopy (SEM). DL and EE were found to be maximum range of 10.0 to 10.79 % and 58.19 to 64.73 % respectively. The SEM Photographs of the resultant microspheres exhibited fairly smooth surfaces and predominantly spherical in appearance. In addition, Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) shown that there was no interaction between the drug and polymer. In vitro and in vivo release studies revealed that the release of dexamethasone was sustained and extended up to 63 days and effectively controlled by the extent of cross-linking agent. Non-clinical parameters such as paw volume, hematological parameters like Erythrocyte Sedimentation Rate (ESR), Paced Cell Volume (PCV), Total Leucocytes Count (TLC), Hemoglobin (Hb), Differential Cell Count (DCC) were investigated in Fruend's Complete Adjuvant (FCA) induced arthritic rats. Radiology and histopathological studies were also performed in order to evaluate the therapeutic efficacy of the DEX-loaded microspheres in extenuating the rat arthritic model.