• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10281-10287
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• 2015

Background: Development of a nanosized polymeric delivery system for erlotinib was the main objective of this research. Materials and Methods: Poly caprolactone-polyethylene glycol-polycaprolactone (PCEC) copolymers with different compositions were synthesized via ring opening polymerization. Formation of triblock copolymers was confirmed by HNMR as well as FT-IR. Erlotinib loaded nanoparticles were prepared by means of synthesized copolymers with solvent displacement method. Results: Physicochemical properties of obtained polymeric nanoparticles were dependent on composition of used copolymers. Size of particles was decreased with decreasing the PCL/PEG molar ratio in used copolymers. Encapsulation efficiency of prepared formulations was declined by decreasing their particle size. Drug release behavior from the prepared nanoparticles exhibited a sustained pattern without a burst release. From the release profiles, it can be found that erlotinib release rate from polymeric nanoparticles is decreased by increase of CL/PEG molar ratio of prepared block copolymers. Based on MTT assay results, cell growth inhibition of erlotinib has a dose and time dependent pattern. After 72 hours of exposure, the 50% inhibitory concentration (IC50) of erlotinib hydrochloride was appeared to be $14.8{\mu}M$. Conclusions: From the obtained results, it can be concluded that the prepared PCEC nanoparticles in this study might have the potential to be considered as delivery system for erlotinib.

• Journal of Pharmaceutical Investigation
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• 제41권2호
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• pp.95-102
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• 2011

An amphiphilic cationic branched methoxy poly (ethylene glycol)-branched polyethylenimine - poly(L-phenylalanine) (mPEG-bPEI-pPhe) block copolymer was successfully synthesized by ring-opening polymerization (ROP) of N-carboxyanhydride of L-phenylalanine (Phe-NCA) with mPEG-bPEI for the preparation of more stable polyelectrolyte complex (PEC) included a hydrophobic interaction. mPEG-bPEI was firstly prepared by the coupling of mPEG and bPEI using hexamethylene diisocyanate (HMDI). The structural properties of mPEG-bPEI-pPhe copolymers were confirmed by $^1H$ NMR. The copolymers exhibited a self-assemble behavior in water above critical aggregate concentration (CAC) in the range of 0.01-0.14 g/L. The CAC of copolymers obviously depended on the hydrophobic block content in the copolymers (the value decreased with the increase of the pPhe block content). The cationic copolymers have the ability to form multi-interaction complex (MIC) with bovine serum albumin (BSA) and plasmid DNA through multi-interaction (electrostatic and hydrophobic interaction). The physicochemical characterization of the complex was carried out by the measurement of zeta potential and particle size. Their zeta-potentials were positive (approximately +10 mV) and their sizes decreased with increasing pPhe contents in the copolymers (PPF/BSA wt% ratio = 2). The complex showed good stability at high ionic strength. Therefore, mPEG-bPEI-pPhe block copolymer was considered as a potential material to enhance the stability of complex including biotherapuetic drugs.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.248-254
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• 2008

Candida magnoliae, an osmotolerant and erythritol producing yeast, prefers D-fructose to D-glucose as carbon sources. For the investigation of the fructophilic characteristics with respect to sugar transportation, a sequential extraction method using various detergents and ultracentrifugation was developed to isolate cellular membrane proteins in C. magnoliae. Immunoblot analysis with the Pma1 antibody and two-dimensional electrophoresis analysis coupled with MS showed that the fraction II was enriched with membrane proteins. Eighteen proteins out of 36 spots were identified as membrane or membrane-associated proteins involved in sugar uptake, stress response, carbon metabolism, and so on. Among them, three proteins were significantly upregulated under the fructose supplying conditions. The hexose transporter was highly homologous to Ght6p in Schizosaccharomyces pombe, which was known as a predominant transporter for the fructose uptake of S. pombe because it exhibited higher affinity to D-fructose than D-glucose. The physicochemical properties of the ATP-binding cassette transporter and inorganic transporter explained their direct or indirect associations with the fructophilic behavior of C. magnoliae. The identification and characterization of membrane proteins involved in sugar uptake might contribute to the elucidation of the selective utilization of fructose to glucose by C. magnoliae at a molecular level.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3188-3194
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• 2014

Compound K (CK) was formulated as polymeric micelles (PM) using Pluronic$^{(R)}$ F-127 to enhance the oral absorption of CK, an intestinal bacterial metabolite of ginseng protopanaxadiol saponin. The physicochemical properties of Ck-loaded PM were characterized and an in vitro transport study using the Caco-2 cell system as well as an in vivo pharmacokinetic study using SD rats was carried out. The hydrodynamic mean particle size of CK-loaded PM (CK-PM) was $254{\pm}23.45nm$ after rehydration and the drug loading efficiency was ca. 99.9%. The FT-IR spectroscopy, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy data supported the presence of a new solid phase in the PM. The $P_{app}$ value of in vitro Caco-2 cell permeation of CK-PM and the oral absorption of CK was enhanced about 1.2-fold and 2.6-fold compared to CK suspension, respectively, showing that the present PM formulation enabled an enhancement of oral CK absorption.

• Composites Research
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• 제29권5호
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• pp.262-268
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• 2016

본 연구에서는 피치계 탄소섬유기반 탄소종이에 바인더 피치와 PAN계 미분쇄 탄소섬유를 첨가하여 저온탄화를 통해 재함침된 탄소종이를 제작하였으며, 미분쇄 탄소섬유의 첨가가 탄소종이의 기계적 및 전기적 특성과 열전도도에 미치는 영향을 알아보았다. 실험 결과, 인장강도는 미분쇄 탄소섬유 함량 10 wt.%부터 20 wt.%까지 첨가하였을 때 크게 증가하였다. 또한, 미분쇄 탄소섬유 함량이 증가함에 따라 계면접촉저항은 감소하였으며, 전기전도도 및 열전도도는 증가하였다. 이러한 결과는 미분쇄된 탄소섬유의 첨가가 탄소종이의 밀도를 증가시킴에 따라 전기적 및 열적 전달 경로가 형성되었기 때문이라고 판단된다.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1164-1170
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• 2006

A triptolide-lysozyme (TP-LZM) conjugate was synthesized to achieve renal specific delivery and to reduce the side effects of triptolide. Triptolide was coupled to lysozyme through succinic via an ester bond with an average coupling degree of 1 mol triptolide per 1 mol lysozyme. The lysozyme can specifically accumulate in the proximal tubular cells of the kidney, making it a potential carrier for targeting drugs to the kidney. The structure of triptolide succinate (TPS) was confirmed by IR, $^{1}H-NMR$, MS and UV. The concentrations of triptolide in various samples were determined by reversed-phase high-performance liquid chromatography (HPLC). In this study, the physicochemical and stability profiles of TP-LZM under various conditions were investgated the stability and releasing profiles of triptolide-lysozyme (TP-LZM) under various conditions. In vitro release trails showed triptolide-lysozyme was relatively stable in plasma (less than 30% of free triptolide released) and could release triptolide quickly in lysosome (more than 80% of free triptolide released) at $37^{\circ}C$ for 24 h. In addition, the biological activities of the conjugate on normal rat kidney proximal tubular cells (NRK52E) were also tested. The conjugate can effectively reduce NO production in the medium of NRK52E induced by lipopolysaccharide (LPS) but with much lower toxicity. These studies suggest the possibility to promote curative effect and reduce its extra-renal toxicity of triptolide by TP-LZM conjugate.

• 에너지공학
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• 제7권1호
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• pp.57-64
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• 1998

폴리에스터와 스테인레스스틸섬유를 재료로 제조된 제전사여과포에 대한 물리화학적 특성시험 및 여과포성능 기초시험을 수행하였다. 실험용먼지로 제철.제강, 시멘트제조, 열공급시설 및 폐기물공정에서 채취된 먼지를 처리하여 사용하였다. 제전사여과포의 물리화학적 특성 실험에서는 산성분위기하에서 인장강도 및 초기탄성계수변화를 조사하였고, Automated Permporometer를 이용하여 평균흐름세공압력, 기포점 세공지름, 평균흐름세공지름 및 세공크기분포를 구하였다. 또한 벤처규모의 여과포 기초성능 시험장치를 이용하여 먼지부하에 따른 압력손실, 먼지통과율 및 여과포성능 평가지표를 산출하였다. 산성가스 및 분위기하에서 제전사여과포의 인장강도는 온도 및 노출시간과 깊은 관련이 있었다. 압력손실은 여과속도와 먼지부하가 증가함에 따라 증가하였으며 증가형태는 먼지의 종류에 따라 달랐다. 먼지 통과율은 먼지종류에 관계없이 먼지부하의 증가에 따라 급격히 감소하는 경향을 나타내었다. 여과포성능지표는 먼지 포집 초기에는 증가했다가 급격히 감소하여 일정하게 유지되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2335-2340
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• 2014

Paclitaxel is hydrophobic in nature and is recognized as a highly toxic anticancer drug, showing adverse effects in normal body sites. In this study, we developed a polymeric nano drug carrier for safe delivery of the paclitaxel to the cancer that releases the drug in a sustained manner and reduces side effects. N-isopropylacrylamide/vinyl pyrrolidone (NIPAAm/VP) nanoparticles were synthesized by radical polymerization. Physicochemical characterization of the polymeric nanoparticles was conducted using dynamic light scattering, transmission electron microscopy, scanning electron microscopy and nuclear magnetic resonance, which confirmedpolymerization of formulated nanoparticles. Drug release was assessed using a spectrophotometer and cell viability assays were carried out on the MCF-7 breast cancer and B16F0 skin cancer cell lines. NIPAAm/VP nanoparticles demonstrated a size distribution in the 65-108 nm range and surface charge measured -15.4 mV. SEM showed the nanoparticles to be spherical in shape with a slow drug release of ~70% in PBS at $38^{\circ}C$ over 96 h. Drug loaded nanoparticles were associated with increased viability of MCF-7 and B16F0 cells in comparison to free paclitaxel. Nano loaded paclitaxel shows high therapeutic efficiency by sustained release action for the longer period of time, i increasing its efficacy and biocompatibility for human cancer therapy. Therefore, paclitaxel loaded (NIPAAm/VP) nanoparticles may provide opportunities to expand delivery of the drug for clinical selection.

• 한국수산과학회지
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• 제53권5호
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• pp.681-687
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• 2020

Physicochemical properties of fucoidan and alginate extracted from Sargassium horneri were investigated. The alginates were extracted and purified via three different routes (CaCl₂, HCl and ethanol routes), and their rheological properties at various concentrations and temperatures were determined. The yield of fucoidan was 3.08%, and it was mainly composed of fucose and galactose. Fourier-transform infrared spectrum of fucoidan showed strong absorption band at 1,254 and 827 cm^-1 corresponding to the sulfate group. Flow behavior of the alginate solution was characterized using the power-law model. The consistency index increased with increasing concentrations. The sodium alginate solution (1.5%) exhibited Newtonian behavior when extracted via the CaCl₂ and HCl routes, while it exhibited pseudoplastic behavior when extracted via the ethanol route. The effect of temperature on the flow behavior was investigated in terms of the activation energy (E_a), which was obtained using the Arrhenius equation. The E_a value corresponding to the alginate solution decreased with increasing shear rates. The E_a values corresponding to the alginate solutions purified via the CaCl₂, HCl, and ethanol routes were 13.54-18.64 kJ/mol, 13.42-19.21 kJ/mol, and 9.51-10.67 kJ/mol, respectively. The low E_a values corresponding to the solutions extracted via the ethanol route suggest that the flow behavior does not depend significantly on temperature.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.329-334
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• 2017

본 논문은 새로운 과립형태의 구강청결제 개발에 있어 동등한 항균력을 가지면서 고형상에서 주성분간의 공융혼합물 생성에 따른 과립의 흐름성 부족을 개선하기 위해 과립의 표면을 흡착시키는 Magnesium aluminometasilicate (Neusilin)이라는 물질을 활용하여 흐름성을 개선하고 부가적으로 구강에서의 붕해시간 및 잔물감이 적은 특성을 가지는 새로운 과립형태의 구강청결제를 제조하였다. 제조된 과립의 흐름성, 밀도, 건조감량 등의 과립특성에 대한 확인을 통해 Neusilin의 양이 전체 과립양 대비 10%이상이 투입되었을 경우 과립의 특성이 개선되는 결과를 확인하였다. 또한 인공타액에서의 붕해시험 및 사람의 구강에서 붕해시간과 잔여물시험 등의 관능시험을 진행하여 보다 개선된 붕해특성 및 관능시험 결과를 확인할 수 있었으며 항균시험을 통해서 이미 시장에서 판매중인 액제형 구강청결제와 동등한 항균력을 보여주는 것으로 확인하였다. 본 연구를 통해 제조된 과립형태의 구강청결제 조성물은 공융혼합물로서 유사한 특성을 가지는 서로 다른 약물을 동시에 함유하는 의약품의 개발에 활용될 수 있어 제약산업의 의약품 개발에서 유용할 것으로 사료된다.