• 폴리머
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• 제34권6호
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• pp.501-506
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• 2010

물에 잘 녹지 않는 고분자량의 키토산을 가수분해하여 수용성을 갖는 저분자량 키토산을 제조하였다. 키토산을 효율적인 유전자 전달체로 개발하기 위하여 항산화제의 일종인 리포산과 결합하여 빗살 형태의 공중합체를 제조하였다. 양친성을 가지는 공중합체는 수용액 상에서 자기조립을 하여 나노입자를 형성하였다. 나노입자의 평균크기는 217.6 nm이었고 유전자와 복합체를 이루었을 때의 평균크기는 170 nm로 나타났다. 새롭게 만들어진 키토산-리포산 공중합체는 낮은 세포독성을 나타내었고 순수한 키토산에 비하여 10배 정도 높은 형질 발현효율을 보여주었다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.2277-2284
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• 2016

Ribosome-inactivating protein (RIP) from Mirabilis jalapa L. leaves has cytotoxic effects on breast cancer cell lines but is less toxic towards normal cells. However, it can easily be degraded after administration so it needs to be formulated into nanoparticles to increase its resistance to enzymatic degradation. The objectives of this study were to develop a protein extract of M. jalapa L. leaves (RIP-MJ) incorporated into nanoparticles conjugated with Anti-EpCAM antibodies, and to determine its cytotoxicity and selectivity in the T47D breast cancer cell line. RIP-MJ was extracted from red-flowered M. jalapa L. leaves. Nanoparticles were formulated based on polyelectrolyte complexation using low viscosity chitosan and alginate, then chemically conjugated with anti-EpCAM antibody using EDAC based on carbodiimide reaction. RIP-MJ nanoparticles were characterised for the particle size, polydispersity index, zeta potential, particle morphology, and entrapment efficiency. The cytotoxicity of RIP-MJ nanoparticles against T47D and Vero cells was then determined with MTT assay. The optimal formula of RIP-MJ nanoparticles was obtained at the concentration of RIP-MJ, low viscosity chitosan and alginate respectively 0.05%, 1%, and 0.4% (m/v). RIP-MJ nanoparticles are hexagonal with high entrapment efficiency of 98.6%, average size of 130.7 nm, polydispersity index of 0.380 and zeta potential +26.33 mV. The $IC_{50}$ values of both anti-EpCAM-conjugated and non-conjugated RIP-MJ nanoparticles for T47D cells (13.3 and $14.9{\mu}g/mL$) were lower than for Vero cells (27.8 and $33.6{\mu}g/mL$). The $IC_{50}$ values of conjugated and non-conjugated RIP-MJ for both cells were much lower than $IC_{50}$ values of non-formulated RIP-MJ (>$500{\mu}g/mL$).

• 공업화학
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• 제28권4호
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• pp.404-409
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• 2017

천연고분자 키토산은 생체적합하고 생분해성의 특성뿐만 아니라 항암, 항균, 콜레스테롤 저하 등의 다양한 생체활성을 갖고 있어 의료용 분야에서 많이 응용되고 있다. 현재 키토산을 약물전달시스템에 응용한 다양한 약물이 담지 된 키토산 나노입자를 개발하여 질병을 치료할 수 있는 연구가 활발히 진행 중에 있다. 키토산에 존재하는 free 아민($-NH_2$) 그룹은 다양한 소수성기를 물리적 화학적 개질을 통해 결합이 가능하며 소수성기가 도입된 키토산은 물에 분산시 자기회합에 의한 shell-core 나노입자를 형성하고 core 부분에 다양한 난용성 약물을 담지하여 물에 대한 용해도를 증가시킬 수 있으며, 단백질, 항암제, 백신 등의 다양한 약물을 담지하여 기존 약물의 부작용을 최소화하여 치료효과를 극대화할 수 있다. 또한, 키토산에 도입된 소수성기에 따라 입자의 크기 및 방출 속도를 제어할 수 있어 다양한 의료용 분야에 응용이 가능하다. 본 총설에서는 다양한 소수성기가 도입된 키토산 나노입자의 제조 및 특성과 특성에 따른 약물전달시스템의 응용성에 관하여 논의 하고자 한다.

• 식품과학과 산업
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• 제53권1호
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• pp.56-68
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• 2020

Recently, chitosan has increased attention in commercial applications in the food industry in terms of its biocompatibility and nontoxicity. In particular, chitosan has been used as a good hosting material for producing nanoparticles due to its unique property of ionic gelation. Chitosan has disadvantages such as low solubility at physiological pH, causing the metabolism of core material in the intestine and gastric juice. To overcome these limitations, various chitosan derivatives such as carboxylated, thiolated, and acylated chitosan have been studied. This review focuses on the changes in the physicochemical properties of chitosan nanoparticles with the introduction of hydrophobic groups, the application of functional nanocapsules as coatings, and their applicability in the food sector. The physicochemical modification of chitosan is expected to be an attractive research field for the development of chitosan applications for food as well as for improving bioavailability in functional food.

• 폴리머
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• 제32권6호
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• pp.544-548
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• 2008

본 연구에서는 키틴의 알칼리 가수분해를 통해 탈아세틸화도가 조절된 세 가지 조건의 키토산을 제조하였고, 이 키토산이 수용성을 지니게 화학적 분해법을 이용해 분자량을 조절하였다. 이렇게 제조된 분자량이 조절된 세 가지 조건의 탈아세틸화도를 가지는 키토산 각각에 항산화제인 리포산을 합성하여 항산화 능력을 가지는 생체 적합성 나노 구조체를 형성하였다. 키토산-리포산의 합성을 확인하기 위하여 분광학적 분석 방법을 사용하여 분석하였다. 키토산-리포산 합성체는 수용액 상태에서 자기조립체를 형성하며 이렇게 형성된 자기조립체 나노 입자는 약 135 nm 정도의 크기를 가지고 있음을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.829-836
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• 2016

Penicillin G acylase (PGA) was immobilized on magnetic Fe₃O₄@chitosan nanoparticles through the Schiff base reaction. The immobilization conditions were optimized as follows: enzyme/support 8.8 mg/g, pH 6.0, time 40 min, and temperature 25 ℃. Under these conditions, a high immobilization efficiency of 75% and a protein loading of 6.2 mg/g-support were obtained. Broader working pH and higher thermostability were achieved by the immobilization. In addition, the immobilized PGA retained 75% initial activity after ten cycles. Kinetic parameters V_max and K_m of the free and immobilized PGAs were determined as 0.113 mmol/min/mg-protein and 0.059 mmol/min/mg-protein, and 0.68 mM and 1.19 mM, respectively. Synthesis of amoxicillin with the immobilized PGA was carried out in 40% ethylene glycol at 25 ℃ and a conversion of 72% was obtained. These results showed that the immobilization of PGA onto magnetic chitosan nanoparticles is an efficient and simple way for preparation of stable PGA.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1333-1338
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• 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
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• 제36권2호
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• pp.149-154
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• 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.

• Korean Chemical Engineering Research
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• 제49권4호
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• pp.475-479
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• 2011

키토산은 천연고분자 물질로 다양한 물리화학적(다중양이온, 반응성 수산화기와 아미노기 그룹), 생물학적(생리활성, 생체적합성, 생분해성) 특성을 가지고 있다. 본 연구에서는 겔형성제로 폴리감마글루탐산을 이용하여 키토산 나노입자를 제조하였다. 나노입자는 폴리감마글루탐산의 카르복실기($-COO^-$)와 키토산의 아미노기($-NH_3^+$)사이의 이온 상호작용에 의해 형성되었다. 키토산(0.1~1 g)을 100 ml 아세트산 용액(1% v/v)에 첨가한 후 상온에서 충분히 용해되도록 하룻밤 동안 교반하였다. 폴리감마글루탐산(0.1 g)은 상온에서 90 ml 증류수에 용해시켰다. 교반되고 있는 폴리감마글루탐산 용액에 키토산 용액을 주사바늘을 통해 상온에서 적가하였다. 입자의 평균 크기는 80~300 nm 범위에서 형성되었다. 키토산/폴리감마글루탐산 나노입자는 중금속 이온들($Cd^{2+}$, $Pb^{2+}$, $Zn^{2+}$, $Cu^{2+}$, $Ni^{2+}$)의 제거를 위해 콜로이드 상태의 흡착 물질로 사용되었다. 나노입자의 중금속 제거 능력은 $Cu^{2+}$ > $Pb^{2+}$ > $Cd^{2+}$ > $Ni^{2+}$ > $Zn^{2+}$의 결과를 보였다.

• Macromolecular Research
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• 제14권1호
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• pp.66-72
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• 2006

The purpose of this study is to develop novel nanoparticles based on polyion complex formation between low molecular weight water-soluble chitosan (LMWSC) and all-trans retinoic acid (atRA). LMWSC nanoparticles encapsulating atRA based on polyion complex were prepared by mixing of atRA into LMWSC aqueous solution using ultrasonication. In FTIR spectra, the carbonyl group of atRA at 1690 $cm^{-1}$ disappeared or decreased when ion complexes were formed between LMWSC and atRA. In ${1}^H$ NMR spectra, specific peaks of atRA disappeared when atRA-encapsulated LMWSC (RAC) nanoparticles were reconstituted into $D_{2}O$ while specific peaks both of atRA and LMWSC appeared in $D_{2}O$/DMSO (1/3, v/v) mixture. XRD patterns also showed that the crystal peaks of atRA were disappeared by encapsulation into LMWSC nanoparticles. LMWSC nanoparticles encapsulating atRA have spherical shapes with particle size below 200 nm. The mechanism of encapsulation of atRA into LMWSC nanoparticles was thought to be an ion complex formation between LMWSC and atRA. LMWSC nanoparticles showed high atRA loading efficiency over 90$\%$ (w/w). AtRA was continuously released from nanoparticles over 10 days. In in vitro cell cytotoxicity test, free atRA showed higher cytotoxic effect against CT 26 colon carcinoma cell line on 1 day. However, RAC nanoparticles showed similar cytotoxicity against CT 26 cells on 2 day. These results suggest the potential for the introduction of LMWSC nanoparticles into various biomedical fields such as drug delivery.