• 제목/요약/키워드: zeta potential value

검색결과 117건 처리시간 0.027초

Entrapment of Ellagic Acid in Dairy Protein-Based Nanoparticles

  • Lee, Mee-Ryung
    • Journal of Dairy Science and Biotechnology
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    • 제36권2호
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    • pp.121-124
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    • 2018
  • Ellagic acid (EA) is a naturally occurring polyphenolic compound in vegetables, nuts, and fruits such as berries. EA has antioxidant, anticancer, anti-allergy, and anti-inflammatory activities. The objectives of this research were to investigate the physicochemical properties of nanoparticles before and after nano-encapsulation of EA in dairy protein and to develop a functional (anti-inflammatory) dairy protein-based beverage containing EA. A particle size analyzer was used to determine the physicochemical and morphological properties. High performance liquid chromatography was used to evaluate the entrapment efficiency of EA. The nanoparticles containing EA were 100 to 200 nm in diameter. The determined poly dispersity index value of 0.3 to 0.4 indicated that the nanoparticles were uniformly distributed with similar size. Zeta-potential values were also similar between the control groups. The entrapment efficiency of EA was nearly 90%. The results indicate the potential for development of nanoparticles containing EA beverage products with anti-inflammatory activity.

Computational Study of the Molecular Structure, Vibrational Spectra and Energetics of the OIO Cation

  • Lee, Sang-Yeon
    • Bulletin of the Korean Chemical Society
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    • 제25권12호
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    • pp.1855-1858
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    • 2004
  • Molecular geometries for the cationic and neutral species of OXO (X=Cl, Br, and I) are optimized using the Hartree-Fock (HF) theory, the second order Moller-Plesset perturbation theory (MP2), the density functional theory with the B3LYP hybrid functional (B3LYP), and the coupled cluster theory using single and double excitation with a perturbational treatment of triplet excitation (CCSD[T]) methods, with two basis sets of triple zeta plus polarization quality. The single point calculations for these species are performed at the CCSD(T,Full) level. The harmonic vibrational frequencies for these species are calculated at the HF, MP2, B3LYP and CCSD(T) levels. The adiabatic ionization potential for OIO is calculated to be 936.7 kJ/mol at the CCSD(T,Full) level and the correct value is estimated to be around 945.4 kJ/mol.

해수의 농도 변화에 따른 bentonite 침전에 대한 유변학적 고찰 (Rheological Study on bentonite Clay Sedimentation with various concentrations of Sea water)

  • 최상원;서호준
    • 한국환경과학회지
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    • 제5권1호
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    • pp.35-41
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    • 1996
  • For studying of coagulation and sedimentation in estuarine clay, we obtained several flow curves with various concentrations of sea water by using Coutte type rotational rheometer. The initial shear stress on high concentration of sea water was observed big, but after this, its value is decreasing with increasing shear rate. The maximum pick of shear stress is decreasing with the decreasing of concentration of sea water The trend is same totally above for viscosity. The sedimentation times with the concentration of sea water vary in $\infty$ ~ 5 minutes. The zeta potential is changed dramatically between 114 and 118 concentration of sea water. That is consistent with the sedimentation graph. From these results, the phenomena of coagulation and sedimentation can be explained with viscoelastic terms on structual formation among particles by the changes of surface potential affected from contacting sea water to dispersed particles.

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티올키토산으로 피복된 EPA(Eicosapentaenoic acid) 함유 리포좀의 제조 및 아토피 감염 쥐에 대한 면역 특성 (Preparation of Thiol-chitosan Coated EPA-containing Liposome and Immune Response in Mouse Model of Atopic Dermatitis)

  • 정효연;김진;이용욱;이기영
    • KSBB Journal
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    • 제25권1호
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    • pp.97-102
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    • 2010
  • The enhancement of immunity for atopic dermatitis with application of eicosapentaenoic acid (EPA)-loaded liposome was evaluated on NC/Nga mice. The EPA-loaded liposome was coated with thiol-chitosan. The liposomes were characterized with transmission electron microscopy (TEM), surface zeta potential & particle size analyzer (Zeta-PSA) and differential scanning calorimetry (DSC). The loading efficiency of EPA in the liposome was about 4.7%. The particle size of the EPA-Ioaded liposome was about 230 nm. The values of Immunoglobulin E (IgE), interleukin-4 (IL-4), and tumor necrosis factor-$\alpha$ (TNF-$\alpha$) were reduced significantly with application of the EPA-loaded liposome. The interferon-$\gamma$ (IFN-$\gamma$) value was increased with the application effect. It is concluded that EPA loaded liposome have immunity advancing effects in mouse model of atopic dermatitis.

인산염 및 불소폐수 처리제로서의 희토류 화합물 적용에 관한 연구 (Application of Rare Earth Compounds for the Treatment of Phosphate and Fluoride in Wastewater)

  • 김진화;신성혜;송혜원;김동수;우상모;권영식
    • 대한환경공학회지
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    • 제22권6호
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    • pp.1127-1137
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    • 2000
  • 인산염 폐수와 불소폐수를 대상으로 각각 $La^{3+}$를 주성분으로 하는 희토수처리제와 조염화희토화합물로 제조된 수처리제를 적용하는 방안을 검토하였다. $La^{3+}$의 인산염 농도 대비 투입몰비에 따른 인산염의 제거양상을 조사한 결과, 투입몰비 0.25에서 약 50% 정도의 인산염이, 그리고 투입몰비 0.5 에서 대부분의 인산염이 제거되는 결과를 보였다. 희토수처리제에 의한 인산염 인의 제거반응은 평형에 신속히 도달하였으며, 온도증가에 따라 인산염의 제거율이 다소 감소하는 경향이 관찰되어 발열반응의 특성을 나타내었다. 희토-인산 결합체의 제타전위는 pH 5.5를 경계로 그 이하에서는 양의 값을, 그리고 그 이상에서는 음의 값을 가지는 것으로 파악되었으며 pH에 따른 제타전위 절대치의 증감과 탁도의 증감은 유사한 경향으로 변화하였다. 불소폐수에 대한 조염화희토 수처리제의 적용에 있어서는 수처리제의 투입량 중가에 따른 잔류불소 농도의 감소 및 탁도와 생생슬러지량의 증대현상이 관찰되었으며, 수처리제의 투입량이 고정된 상태에서 응집제량의 변화에 따른 불소처리효과에 대한 검토에서는 응집제의 주입량이 증가됨에 따라 잔류불소량 및 탁도는 감소하고 슬러지 발생량은 증가하는 경향이 파악되었다.

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Poly(Ethylene Glycol)-branched Polyethylenimine-poly(L-phenylalanine) Block Copolymer Synthesized by Multi-initiation Method for Formation of More Stable Polyelectrolyte Complex with Biotherapeutic Drugs

  • Park, Woo-Ram;Na, Kun
    • 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.

Recombinant Human Epidermal Growth Factor (rhEGF)-loaded Solid Lipid Nanoparticles: Fabrication and Their Skin Accumulation Properties for Topical rhEGF Delivery

  • Hwang, Hee-Jin;Han, Sunhui;Jeon, Sangok;Seo, Joeun;Oh, Dongho;Cho, Seong-Wan;Choi, Young Wook;Lee, Sangkil
    • Bulletin of the Korean Chemical Society
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    • 제35권8호
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    • pp.2290-2294
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    • 2014
  • For the present study, rhEGF was encapsulated into solid lipid nanoparticles (SLNs). The SLNs were prepared by the $W_1/O/W_2$ double emulsification method combined with the high pressure homogenization method and the physical properties such as particle size, zeta-potential and encapsulation efficiency were measured. The overall particle morphology of SLNs was investigated using a transmission electron microscopy (TEM). The percutaneous skin permeation and accumulation property of rhEGF was evaluated using Franz diffusion cell system along with confocal laser scanning microscopy (CLSM). The mean particle size of rhEGF-loaded SLNs was $104.00{\pm}3.99nm$ and the zeta-potential value was in the range of -$36.99{\pm}0.54mV$, providing a good colloidal stability. The TEM image revealed a spherical shape of SLNs about 100 nm and the encapsulation efficiency was $18.47{\pm}0.22%$. The skin accumulation of rhEGF was enhanced by SLNs. CLSM image analysis provided that the rhEGF rat skin accumulation is facilitated by an entry of SLNs through the pores of skin.

아스타잔틴을 포함하는 나노에멀젼의 안정성 향상을 위한 신규 Glyceryl Ester 이용 캡슐화 (Novel Encapsulation with New Glyceryl Ester Vesicle Enhances Stability of Nanoemulsion Containing Astaxanthin)

  • 김동명;홍원기;공수성;이언엽
    • 대한화장품학회지
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    • 제39권3호
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    • pp.225-231
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    • 2013
  • 아스타잔틴을 포함하는 수중유형 형태의 나노에멀젼을 고압균질기를 이용하여 제조하였다. 이에 유화조건, 유화제 종류, 유화제 농도 그리고 아스타잔틴 농도에 따라 최적화를 되었다. 나노에멀젼의 안정성은 제타포텐셜, FF-SEM, 입도분석기, 색차계를 이용하여 측정하였다. 제조된 아스타잔틴 나노에멀젼의 입도는 160 ~ 190 nm로 균일하였으며 레시친에 의한 나노에멀젼 보다 glyceryl citrate/lactate/linoleate/oleate에 의한 나노에멀젼이 더욱 안정하고 균일한 입도분포를 가졌다. 아스타잔틴의 봉입도는 HPLC, FF-SEM을 이용하여 확인 하였으며, 제형 구성 후 보관조건에서의 안정도 및 제타 포텐셜 값도 -41의 우수한 결과를 나타내었다.

전기영동형 전자종이를 위한 $TiO_2$ 나노분말의 분산 제어 (A control dispersion of $TiO_2$ nano powder for electronic paper of electrophoresis)

  • 김중희;오효진;이남희;황종선;김선재
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.324-327
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    • 2005
  • An electrophoretic display using $TiO_2$ particles is the most promising candidate because it offers various advantages such as ink-on-paper appearance, good contrast ratio, wide viewing angle, image stability in the off-state and extremely low power consumption. The core technology of electrophoretic display is the dispersion controlling of $TiO_2$ nano particles in nonaqueous solution. To prepare an ink for electronic paper using electrophoretic properties of $TiO_2$ nano particles, cyclohexane with low dielectric constant and transparency, polyethylene for producing polymer coating layer which reduces apparent gravity of $TiO_2$, and $TiO_2$ powders were mixed together by planetary-mill. The zeta-potential value of $TiO_2$ particles in cyclohexane was measured about -40mV, but was measured over -110mV by dispersant attached to polyethylene-coated $TiO_2$ surface. Prepared electronic ink was filled in cross patterned micro-wall with $200{\mu}m$ in width and $40{\mu}m$ in height on ITO glass designed by photolithography. The response time of electronic paper evaluated by mobility of $TiO_2$ particle between micro-walls was measured 0.067sec, but the drift velocity from reflectance wave form during reverse from of electronic ink was measured 0.07cm/sec.

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파이토케미컬 펩타이드 유도체를 포함하는 다양한 리포좀 제형의 안정성 (Stability of Various Liposome Formulation Containing the Phytochemical-Peptide Derivatives)

  • 한병석;김수영;이경록;서효현;모상현
    • 대한화장품학회지
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    • 제42권2호
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    • pp.135-143
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    • 2016
  • 본 연구에서는 파이토케미컬 펩타이드 유도체를 포함하는 니오좀 및 리포좀 제형의 안정성을 조사하였다. 여러 가지 조건에서 레시틴 혹은 계면활성제를 이용하여 제조된 리포좀 중에서 sodium palmitoyl sarcosinate와 마카다미아넛 오일을 이용한 니오좀의 안정성이 제일 우수하였다. 파이토케미컬 펩타이드 함유 니오좀(N9)의 형태는 TEM으로 확인하였으며, 입자크기는 95.7 nm로 관찰되었다. N9의 안정성은 Turbiscan 결과 ($0^{\circ}$$45^{\circ}$)와 제타포텐셜(-78.19 mV)로 확인하였다. N9의 펩타이드 봉입률은 BCA assay 결과 65.2%로 관찰되었다.