• Title/Summary/Keyword: $\zeta$-potential

Search Result 615, Processing Time 0.03 seconds

Comparison of the stability between branched-chain amino acid (BCAA)-coated liposome and double emulsion (분지쇄아미노산(BCAA)이 포집된 더블에멀션과 리포좀의 안정성 비교)

  • Lee, YunJung;Lee, SangYoon;Shin, Hyerin;Kang, Guhyun;Wi, Gihyun;Ko, Eun Young;Cho, Youngjae;Choi, Mi-Jung
    • Korean Journal of Food Science and Technology
    • /
    • v.50 no.6
    • /
    • pp.636-641
    • /
    • 2018
  • This study was conducted to compare the stability between branched-chain amino acid (BCAA)-encapsulated liposome and double emulsion (DE). Liposome was produced by high-speed homogenization and ultrasonication whereas DE was prepared by homogenizing with surfactants. All samples were fixed at pH 4 and 7 and stored at 4, 25, and $40^{\circ}C$ for 5 days. Encapsulation efficiency and cumulative release rate were measured under $4^{\circ}C$ and at $25^{\circ}C$. The results showed that the size of BCAA-coated liposome was greater at pH 7 than at pH 4. The zeta-potential value of BCAA-coated liposome was greater at pH 4 than at pH 7. It was supposed that the negatively charged liposomes attracted the positively charged BCAAs at pH 4 resulting in the formation of the vesicle with smaller size. Particle size of DE was smaller than $100{\mu}m$. Encapsulation efficiencies of BCAA in DE or liposome were over 97%, approximately, and the cumulative release rates of them were below 30% for 5 days.

Effects of zinc-bearing palygorskite on rumen fermentation in vitro

  • Chen, Mengjiao;Xi, Yumeng;Zhang, Lin;Zeng, Hanfang;Li, Yeqing;Han, Zhaoyu
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.32 no.1
    • /
    • pp.63-71
    • /
    • 2019
  • Objective: The aim of the study was to investigate the effect of zinc-bearing palygorskite (Zn-Pal) on rumen fermentation by in vitro gas-production system. Methods: In trial, 90 incubators were evenly divided into five groups: control (0% Zn-Pal), treatment I (0.2% Zn-Pal), treatment II (0.4% Zn-Pal), treatment III (0.6% Zn-Pal), and treatment IV (0.8% Zn-Pal). The contents of zinc for treatments were 0, 49, 98, 147, 196 mg/kg, respectively. The main chemical composition and microstructure of Zn-Pal was investigated by X-ray diffraction. The physicochemical features were evaluated by Zeta potential analysis, cation-exchange capacity, ethylene blue absorption and specific surface area (the Brunauer-Emmett-Teller method). In vitro gas production (GP) was recorded at 3, 6, 9, 12, 18, 24, 36, 48, 60, and 72 h incubation. Incubation was stopped at 0, 6, 12, 24, 48, and 72 h and the inoculants were tested for pH, microbial protein yield (MCP), $NH_3-N$, volatile fatty acids (VFAs), lipopolysaccharide (LPS). Results: The results showed that the GP in the treatment groups was not significantly different from the control groups (p>0.05). Compared to the control group, pH was higher at 24 h, 48 h (p<0.05), and 72 h (p<0.01) (range 6 to 7). The concentration of $NH_3-N$ in the three treatment groups was higher than in the control group at 24 h (p<0.01), meanwhile, it was lower at 48 h and 72 h (p<0.01), except in the treatment IV. The concentration of MCP in treatment I group was higher than in the control at 48 h (p<0.01). Compared with control, the LPS concentration in treatment III became lower at 12 h (p<0.05). Total VFAs in treatments were higher than in the control at 24 h, 48 h (p<0.05). Conclusion: These results suggest that the addition of Zn-Pal can improve the rumen fermentation, especially when adding 0.2% Zn-Pal.

Identification and confirmation of 14-3-3 ζ as a novel target of ginsenosides in brain tissues

  • Chen, Feiyan;Chen, Lin;Liang, Weifeng;Zhang, Zhengguang;Li, Jiao;Zheng, Wan;Zhu, Zhu;Zhu, Jiapeng;Zhao, Yunan
    • Journal of Ginseng Research
    • /
    • v.45 no.4
    • /
    • pp.465-472
    • /
    • 2021
  • Background: Ginseng can help regulate brain excitability, promote learning and memory, and resist cerebral ischemia in the central nervous system. Ginsenosides are the major effective compounds of Ginseng, but their protein targets in the brain have not been determined. Methods: We screened proteins that interact with the main components of ginseng (ginsenosides) by affinity chromatography and identified the 14-3-3 ζ protein as a potential target of ginsenosides in brain tissues. Results: Biolayer interferometry (BLI) analysis showed that 20(S)-protopanaxadiol (PPD), a ginseng saponin metabolite, exhibited the highest direct interaction to the 14-3-3 ζ protein. Subsequently, BLI kinetics analysis and isothermal titration calorimetry (ITC) assay showed that PPD specifically bound to the 14-3-3 ζ protein. The cocrystal structure of the 14-3-3 ζ protein-PPD complex showed that the main interactions occurred between the residues R56, R127, and Y128 of the 14-3-3 ζ protein and a portion of PPD. Moreover, mutating any of the above residues resulted in a significant decrease of affinity between PPD and the 14-3-3 ζ protein. Conclusion: Our results indicate the 14-3-3 ζ protein is the target of PPD, a ginsenoside metabolite. Crystallographic and mutagenesis studies suggest a direct interaction between PPD and the 14-3-3 ζ protein. This finding can help in the development of small-molecular compounds that bind to the 14-3-3 ζ protein on the basis of the structure of dammarane-type triterpenoid.

A Study on the Design of Stearic Acid-Based Solid Lipid Nanoparticles for the Improvement of Artificial Skin Tissue Transmittance of Serine (Serine 의 인공피부조직 투과 개선을 위한 Stearic Acid 기반 고형지질나노입자의 설계 연구)

  • Yeo, Sooho
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.47 no.2
    • /
    • pp.179-184
    • /
    • 2021
  • Stratum corneum known as a skin barrier, which maintains water in skin, is the outer layer of the skin. Natural moisturizing factors (NMF) are one of the constituents in stratum corneum and amino acids are the highest components among NMF. In this study, we designed stearic acid-based solid lipid nanoparticles (SLNs) for improved skin penetration of serine (Ser). Ser-capsulated SLN was manufactured by double-melting emulsification method. The mean particle size and zeta potential of SLNs were 256.30 ~ 416.93 nm and -17.60 ~ -35.27 mV, respectively. The higher the degree of hydrophobicity or hydrophilicity of emulsifiers, the smaller the particle size and the higher the stability and capsulation rate. In addition, skin penetration was conducted using SkinEthicTM RHE which is one of the reconstructed human epidermis models. The results of Ser penetration demonstrated that all SLNs enhanced than serine solution. The amount of enhanced Ser penetration from SLNs were approximately 4.1 ~ 6.2 times higher than that from Ser solution. Therefore, Ser-loaded SLN might be a promising drug delivery system for moisturizing formulation in cosmeceutical.

Polyethyleneimine based Delivery System Coated with Hyaluronate Amine for Improved pDNA Transfection Efficiency (개선된 플라스미드 DNA 전달 효율을 위한 히알루론 아민 코팅 폴리에틸렌이민 기반 전달 시스템)

  • Oh, Kyoung-yeon;Jang, Yongho;Lee, Eunbi;Kim, Tae-ho;Kim, Hyuncheol
    • Applied Chemistry for Engineering
    • /
    • v.33 no.1
    • /
    • pp.83-89
    • /
    • 2022
  • Since the pandemic of COVID-19, active investigation to develop immunity to infectious disease by delivering nucleic acids has been proceeded. Particularly, many studies have been conducted on non-viral vector as several vital side-effects which were found on nucleic acid delivery system using viral vectors. In this study, we have developed plasmid DNA (pDNA) loaded-hyaluronic acid derivative (HA) coated-polyethyleneimine (PEI) based polyplex for enhanced nucleic acid delivery efficiency. We have optimized the ratio of pDNA : PEI : HA by measuring size and protein transcription efficiency. The final product, polyplex-HA, was characterized through measuring size, zeta-potential and TEM image. Intracellular uptake and protein transcription efficiency were compared to commercially available transfection reagent, lipofectamine, through fluorescence image and flow cytometry. In conclusion, polyplex-HA presents a novel gene delivery system for efficient and stable protein transcription since it is available for delivering various genetic materials and has less immunoreactivity.

Study on Stabilization of Retinaldehyde using Drug-in-Cyclodextrinin-Liposome (DCL) for Skin Wrinkle Improvement (레틴알 안정화를 위한 사이클로덱스트린-리포좀에 관한 연구)

  • Ha, Ji Hoon;Choi, Hyeong;Hong, In Ki;Han, Sang-Kuen;Bin, Bum Ho
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.48 no.1
    • /
    • pp.77-85
    • /
    • 2022
  • Retinaldehyde (RA), vitamin A derivative, is an intermediate between retinol and retinoic acid and has an excellent wrinkle improving effect. In this study, Drug-in-cyclodextrin-in-liposome (DCL) was used to enhance the stability and skin penetration of RA. The complex of RA and hydroxypropyl-beta-cyclodextrin (HP-β-CD) was prepared by the freeze-drying method, and the presence or absence of inclusion of retinal was confirmed by UV-Vis spectrometer, FT-IR and SEM images. RA was captured in HP-β-CD about 95.6% on 1 : 15 (w/w). The retinal-HP-β-CD complex was encapsulated in liposomes using a homomixer and microfluidizer, with an average particle size of 215 ± 4.2 nm and a zeta potential of -31.2 ± 0.5 mv. In the evaluation of the degradation stability of RA, degradation rate of RA-HP-β-CD-liposomes in water was 1.8% higher than RA-liposome (5.8%), RA-HP-β-CD complex (9.7%) and RA alone (37.6%). RA cream (0.05% RA) including RA-HP-β-CD-liposomes was prepared for clinical test with wrinkle-improving efficacy and skin dermis denseness evaluated for 2 or 4 weeks. RA cream showed a significant wrinkle improving effect without skin irritation. In conclusion, it was confirmed that the double stabilization technology using the DCL system contribu tes to the effect of improving skin wrinkles by increasing the stabilization of retinal.

Effect of Ultrasonic Irradiation on Ozone Nanobubble Process for Phenol Degradation (페놀 분해를 위한 오존 나노기포 공정에서 초음파 조사의 영향)

  • Lee, Sangbin;Park, Jae-Woo
    • Journal of the Korean GEO-environmental Society
    • /
    • v.23 no.3
    • /
    • pp.23-29
    • /
    • 2022
  • In this study, we investigated the ozone nanobubble process in which nanobubble and ultrasonic cavitation were applied simultaneously to improve the dissolution and self-decomposition of ozone. To confirm the organic decomposition efficiency of the process, a 200 mm × 200 mm × 300 mm scale reactor was designed and phenol decomposition experiments were conducted. The use of nanobubble was 2.07 times higher than the conventional ozone aeration in the 60 minutes reaction and effectively improved the dissolution efficiency of ozone. Ultrasonic irradiation increased phenol degradation by 36% with nanobubbles, and dissolved ozone concentration was lowered due to the promotion of ozone self-decomposition. The higher the ultrasonic power was, the higher the phenol degradation efficiency. The decomposition efficiency of phenol was the highest at 132 kHz. The ozone nanobubble process showed better decomposition efficiency at high pH like conventional ozone processes but achieved 100% decomposition of phenol after 60 minutes reaction even at neutral conditions. The effect by pH was less than that of the conventional ozone process because of self-decomposition promotion. To confirm the change in bubble properties by ultrasonic irradiation, a Zetasizer was used to measure the bubbles' size and zeta potential analysis. Ultrasonic irradiation reduced the average size of the bubbles by 11% and strengthened the negative charge of the bubble surface, positively affecting the gas transfer of the ozone nanobubble and the efficiency of the radical production.

Preparation of ZnO@TiO2 nano coreshell structure by the polymerized complex and sol-gel method (착체중합법과 sol-gel법에 의한 ZnO@TiO2 나노 코아쉘 구조의 제조)

  • Lim, Chang Sung
    • Analytical Science and Technology
    • /
    • v.21 no.3
    • /
    • pp.237-243
    • /
    • 2008
  • Nano core shell structures of $TiO_2$ particles coated on surface of ZnO nanoparticles were prepared by the polymerized complex and sol-gel method. The average particle size of ZnO by the polymerized complex method showed 100 nm and the average particle size of $TiO_2$ by the sol-gel method showed below 10 nm. The average particle size of $ZnO@TiO_2$ nano core shell struture represented about 150 nm. The agglomeration between the ZnO particles using the polymerized complex method was highly controlled by the uniform absorption of $TiO_2$ colloid on the spherical ZnO surfaces. The driving force of heterogeneous bonding between ZnO and $TiO_2$ was induced by the Coulomb force. The ZnO and $TiO_2$ particles electrified with + and - charges, respectively, resulted in strong bonding by the difference of iso-electric point (IEP) when they laid neutrality pH area, depending on the heterogeneous surface electron electrified by the different zeta potential on the pH values.

Assessment on Impact Factor for Dehydration of Mine Drainage Sludge Using Flocculant and Dewatering Tube(KOMIR-Tube System) (응집제 및 탈수튜브(KOMIR-Tube 시스템)를 활용한 광산배수 슬러지 탈수 영향인자 평가)

  • Misun Park;Juin Ko;Gwanin Bak;Seunghan Baek
    • Economic and Environmental Geology
    • /
    • v.57 no.2
    • /
    • pp.263-270
    • /
    • 2024
  • In this study, impact factors for dehydration with KOMIR-Tube system using flocculant and dewatering tube were evaluated for mine drainage sludges. The experiments were conducted on semi-active facility sludges with water contents above 90 % using KOMIR-Tube system. The flocculant and input amount were determined from laboratory experiment and the dewatering efficiency was verified onsite experiment. The sludge characteristics were identified by instrumental analysis such as zeta potential measurement, particle size analysis, XRD, XRF and SEM-EDS. Selection of flocculants for sludge dewatering treatment need to consider not only precipitated rate but also filterated rate. Floc size has to keep at least 0.7 mm. From on-site experiments, sludge dewatering using KOMIR-Tube system suggests to carry out April and May that is low rainfall and humidity considering to climate conditions. Also, dewatering rate depends on the crystal degree of mineral that mainly makes up sludges. Particularly, goethite of the iron hydroxides has better dewatering rate than ferrihydrite. Ferrihydrite is low degree of crystallinity and uncleared or broad shaped crystal, goethite is good crystallinity with needle shaped crystal so that the effect of flocculation and dewatering showed to depend on the crystal. In results, impact factors of dewatering for mine drainage sludges are related to flocculant, climate, crystallinity and shape of iron hydroxides.

The Preparation and Physicochemical Properties of Dipalmitoylphosphatidylcholine/Cholesterol/Fluorinated Surfactant Vesicle Incorporated Fatty Acid Salt (불소화지방산염 첨가에 의한 디팔미토일포스파티딜콜린/콜레스테롤/불소화계면활성제 베지클의 제조와 물성 측정 연구)

  • Park, Young Ju;Kwon, Kyung Ok;Kim, Myung Ja
    • Applied Chemistry for Engineering
    • /
    • v.9 no.3
    • /
    • pp.457-461
    • /
    • 1998
  • The vesicle system of DPPC(dipalmitoylphosphaticylcholine)/Chol(Cholesterol) has been modified by incorporating various mole fractions of flourinated surfactant($C_8F_{17}(CH_2)_2OCO-CH_2CH(SO_3Na)COO(CH_2)_2C_8F_{17}$. Sodium bis(1H,1H,2H,2H-heptadecaflurododecyl)-2-sulfosuccinate, FS)/fluorinated fatty acid salt ($C_7F_{15}COONH_4$, ammoniumpentadecaflurooctyrate, FFS), and their physicochemical properties have been investigated in an attempt to enhance the stability of phospholipid vesicle system. The ${\zeta}$-potential measurement by use of Zetamaster sub-micron Particle Electrophoresis Analyzer (Malvern Co.) showed that a charged homogeneous DPPC/Chol/FS vesicle has been formed owing to the incorporated FFS effect on the membrane, playing a role as a cosurfactant in the bilayer between DPPC and FS components. With increase in the concentration of FFS, it was found that the particle size and also surface charge of the DPPC/Chol/FS vesicle decreased. The stability of DPPC/Chol/FS/FFS liposome was found to be enhanced significantly compared to that of DPPC/Chol/FS according to the dispersity change as a function of time. The release rate of dye molecule of Methylene Blue from the DPPC/Chol/FS/FFS vesicle was determined to be slower than that of DPPC/Chol/FS system, and it may be attributed to the increase in microviscosity of the hydrophobic region in the bilayer. The affinfinity of DPPC/Chol/FS/FFS vesicles to albumin was found to be slightly lowered compared to that of DPPC/Chol/FS. Based on these findings, it was confirmed that a more stable and homogeneous vesicle system of DPPC/Chol/FS could be prepared by addition of FFS, acting as a cosurfactant in the aggregate formation.

  • PDF