AB loop engineered ferritin nanocages for drug loading under benign experimental conditions

2019 ◽  
Vol 55 (82) ◽  
pp. 12344-12347 ◽  
Author(s):  
Wenming Wang ◽  
Lele Wang ◽  
Guobang Li ◽  
Guanghua Zhao ◽  
Xuan Zhao ◽  
...  
Keyword(s):  
Drug Loading ◽  
Selective Removal ◽  
Experimental Conditions

Selective removal of several residues from the AB loop of ferritin makes it more suitable for drug loading under benign experimental conditions.

scholarly journals Preparation and Characterization of PEG-PLA Genistein Micelles Using a Modified Emulsion-Evaporation Method

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Qiuchen Cheng ◽  
Wen Qin ◽  
Yanhong Yu ◽  
Guojian Li ◽  
Jizhou Wu ◽  
...  
Keyword(s):  
Smooth Muscle Actin ◽  
Drug Loading ◽  
In Vitro Release ◽  
Tween 80 ◽  
Original Method ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Evaporation Method ◽  
Genistein Treatment

The objective of this study is to improve the bioavailability of genistein by encapsulation with polyethylene glycol-polylactic acid (PEG-PLA) copolymers. Genistein micelles (GMs) prepared using a modified emulsion-evaporation method were more stable than those made with the original method. The effect of polyvinyl alcohol, Tween 80, sonication time, PEG-PLA/genistein ratio, and organic phase (acetone)/H2O ratio on the size, polydispersity index, encapsulation efficiency, and drug loading efficiency of GMs was investigated. GMs were obtained and characterized under optimal experimental conditions. For long-term storage, GMs were lyophilized by freeze drying with trehalose to produce genistein lyophilized powder (GLP). The analysis of GLP by Fourier-transform infrared spectroscopy and differential scanning calorimetry showed that genistein was successfully incorporated into the micellar structure. In vitro release experiments revealed that the incorporation of genistein into PEG-PLA copolymers significantly improved its solubility and bioavailability. GLP was more potent in inhibiting the proliferation of HSC-T6 cells than genistein. Treatment with GLP at 10–20 μg/mL for 48 h significantly inhibited the protein expression of α-smooth muscle actin and collagen I in HSC-T6 cells compared with the control. These data demonstrated that the improved solubility and bioavailability of genistein in the form of GLP enhanced its antifibrotic effect in vitro.

A convenient protection for 4-oxopyrimidine moieties in nucleosides by the pivaloyl group

2010 ◽  
Vol 75 (1) ◽  
pp. 33-57 ◽  
Author(s):  
Michał Sobkowski
Keyword(s):  
Selective Removal ◽  
Protecting Group ◽  
Experimental Conditions ◽  
Reaction Proceeding ◽  
Mild Conditions ◽  
Acidic Conditions ◽  
Rapid Reaction

Application of the pivaloyl group as a protection for the N3 position of thymidine and uridine was investigated. Pivaloylation of thymidine is a very rapid reaction proceeding under mild conditions with excellent regioselectivity for sugar or thymine moiety, depending on the amines used. Several pivaloylated thymidine derivatives were obtained by treatment of unprotected thymidine with pivaloyl chloride under various experimental conditions. Stability of the N3-pivaloyl protecting group under basic and acidic conditions was evaluated and the conditions for its selective removal were found.

scholarly journals Preparation, Characterization and Pharmacokinetics Evaluation of Imperatorin Lipid Microsphere and Its Effect on Proliferation of MDA-MB-231

2018 ◽  
Author(s):  
Xinli Liang ◽  
Xulong Chen ◽  
Guowei Zhen ◽  
Tao Tang ◽  
Chunyan Wang ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Response Surface ◽  
Encapsulation Efficiency ◽  
Drug Loading ◽  
Experimental Conditions ◽  
Zeta Potentials ◽  
Preparation Conditions ◽  
Egg Lecithin ◽  
Central Composite ◽  
Lipid Microsphere

Imperatorin is a chemical compound belong to Linear furan coumarins. Imperatorin is attracting considerable attention because of its anti-tumor, antibacterial, anti-inflammatory, anticoagulant and inhibition of myocardial hypetrophy and other pharmacological efficacy. However, imperatorin has limited water solubility and preferable lipid solubility, we decided to design and synthesize imperatorin lipid microsphere, to optimize preparation conditions. The aim was to develop and formulate imperatorin lipid microsphere through nano emulsion technology and apply the response surface-central composite design to optimize the imperatorin lipid microsphere formulation. Influence of content of amount of egg lecithin(A), amount of poloxamer188(B), soybean oil for injection accounted for the total percentage of oil phase(C) were investigated. Integrated effect of dependent variables including particle size(Y1), polydispersity index(Y2), Zeta potentials(Y3), drug loading(Y4), encapsulation efficiency(Y5). Data of overall desirabiities were fitted to a second-order polynomial equation, through which three dimensional response surface graphs were described. Optimum experimental conditions were calculated by Design-Expert 8.06. Results indicated that the optimum preparation conditions were as follows: egg lecithin amount 1.39 g, poloxamer188 amount 0.21 g, soybean oil for injection amount 10.57%. Preparation of imperatorin lipid microsphere according to the optimum experimental conditions resulted in an overall desirability of 0.7286, while the particele size (168±0.54) nm, polydispersity index (PDI) (0.138±0.02), Zeta potentials (−43.5±0.5) mV, drug loading (0.833±0.27) mg·mL−1, encapsulation efficiency (90±1.27)%. The difference between observed and predicted values of the overall desirability of the optimum formulation was in range from 2.4% to 4.3%. Subsequently, using the Scanning electron microscopy to observe the micromorphology of imperatorin lipid microsphere, the result shows that round globular of relatively uniform and sizes within 200nm.The proliferation study of imperatorin lipid microsphere on MDA-MB-231 was investigated by MTT method. Furthermore, pharmacokinetics in Sprague Dawley rats were evaluated using orbital bleeding. A sensitive and reliable liquid chromatography with High Performance Liquid Chromatography (HPLC) method was established and validated for the quantification of imperatorin in rat plasma samples. The data were calculated by DAS (Drug and statistics) pharmacokinetic software version3.2.6 (China). Results demonstrated that imperatorin lipid microsphere can significantly enhance the bioavailability of imperatorin and can significantly inhibit MDA-MB-231 cell proliferating. In conclusion, our results suggersted that the response surface-central composite design is suitable for the optimized lipid microspere formulation. Imperatorin Lipid microsphere can improve the bioavailability of imperatorin and inhibit the proliferation of MDA-MB-231 than that of imperatorin.

scholarly journals Plasmon-Enhanced Controlled Drug Release from Ag-PMA Capsules

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2267 ◽  
Author(s):  
Giulia Neri ◽  
Carmelo Corsaro ◽  
Enza Fazio
Keyword(s):  
Drug Release ◽  
Laser Irradiation ◽  
Drug Carrier ◽  
Drug Loading ◽  
Controlled Drug Release ◽  
Experimental Conditions ◽  
Power Intensity ◽  
Acid Sodium Salt ◽  
Demand Control ◽  
Smart Drug

Silver (Ag)-grafted PMA (poly-methacrylic acid, sodium salt) nanocomposite loaded with sorafenib tosylate (SFT), an anticancer drug, showed good capability as a drug carrier allowing on-demand control of the dose, timing and duration of the drug release by laser irradiation stimuli. In this study, the preparation of Ag-PMA capsules loaded with SFT by using sacrificial silica microparticles as templates was reported. A high drug loading (DL%) of ∼13% and encapsulation efficiency (EE%) of about 76% were obtained. The photo-release profiles were regulated via the adjustment of light wavelength and power intensity. A significant improvement of SFT release (14% vs. 21%) by comparing SFT-Ag-PMA capsules with Ag-PMA colloids under the same experimental conditions was observed. Moreover, an increase of drug release by up to 35% was reached by tuning the laser irradiation wavelength near to Ag nanoparticles’ surface plasmon resonance (SPR). These experimental results together with more economical use of the active component suggest the potentiality of SFT-Ag-PMA capsules as a smart drug delivery system.

scholarly journals Preparation, Characterization, and Pharmacokinetic Evaluation of Imperatorin Lipid Microspheres and Their Effect on the Proliferation of MDA-MB-231 Cells

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 236 ◽  
Author(s):  
Xinli Liang ◽  
Xulong Chen ◽  
Guowei Zhao ◽  
Tao Tang ◽  
Wei Dong ◽  
...  
Keyword(s):  
Particle Size ◽  
Response Surface ◽  
Encapsulation Efficiency ◽  
Drug Loading ◽  
Experimental Conditions ◽  
Zeta Potentials ◽  
Preparation Conditions ◽  
Egg Lecithin ◽  
Central Composite ◽  
Lipid Microsphere

Imperatorin is a chemical compound belonging to the linear furanocoumarins. Imperatorin is attracting considerable attention because of its antitumor, antibacterial, anti-inflammatory, and anticoagulant activities, inhibition of myocardial hypertrophy, and other pharmacological efficacies. However, imperatorin has limited water solubility and has better lipid solubility; thus, we decided to design and synthesize imperatorin lipid microspheres to optimize the preparation conditions. The aim was to develop and formulate imperatorin lipid microspheres through nanoemulsion technology and apply the response surface–central composite design to optimize the imperatorin lipid microsphere formulation. The influence of the amounts of egg lecithin, poloxamer 188, and soybean oil for injection on the total percentage of the oil phase was investigated. The integrated effect of dependent variables, including particle size, polydispersity index, zeta potentials, drug loading, and encapsulation efficiency, was investigated. Data of overall desirabilities were fitted to a second-order polynomial equation, through which three-dimensional response surface graphs were described. Optimum experimental conditions were calculated by Design-Expert 8.06. Results indicated that the optimum preparation conditions were as follows: 1.39 g of egg lecithin, 0.21 g of poloxamer 188, and 10.57% soybean oil for injection. Preparation of imperatorin lipid microspheres according to the optimum experimental conditions resulted in an overall desirability of 0.7286, with the particle size of 168 ± 0.54 nm, polydispersity index (PDI) of 0.138 ± 0.02, zeta potentials of −43.5 ± 0.5 mV, drug loading of 0.833 ± 0.27 mg·mL−1, and encapsulation efficiency of 90 ± 1.27%. The difference between the observed and predicted values of the overall desirability of the optimum formulation was in the range from 2.4% to 4.3%. Subsequently, scanning electron microscopy was used to observe the micromorphology of the imperatorin lipid microspheres, showing round globules of relatively uniform shape and sizes within 200 nm. The effect of imperatorin lipid microspheres on MDA-MB-231 proliferation was investigated by the MTT method. Furthermore, pharmacokinetics in Sprague-Dawley rats was evaluated using orbital bleeding. A sensitive and reliable liquid chromatography with the high-performance liquid chromatography (HPLC) method was established and validated for the quantification of imperatorin in rat plasma samples. The data were calculated by DAS (drug and statistics) Pharmacokinetic Software version 3.3.0 (Version 3.3.0, Shanghai, China). Results demonstrated that imperatorin lipid microspheres can significantly enhance the bioavailability of imperatorin and can significantly inhibit MDA-MB-231 cell proliferation. In conclusion, our results suggested that the response surface–central composite design is suitable for achieving an optimized lipid microsphere formulation. Imperatorin lipid microspheres can improve the bioavailability of imperatorin and better inhibit the proliferation of MDA-MB-231 cells as compared to imperatorin alone.

Electrolytic Isolation of Twin-Type Shock Deformation Structures

1967 ◽  
Vol 25 ◽  
pp. 318-319
Author(s):  
F. I. Grace ◽  
L. E. Murr
Keyword(s):  
Grain Boundaries ◽  
Thin Foil ◽  
Electrolyte Composition ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electron Transmission ◽  
Deformation Structures ◽  
The Matrix ◽  
Average Current ◽  
Specimen Edge

During the course of electron transmission investigations of the deformation structures associated with shock-loaded thin foil specimens of 70/30 brass, it was observed that in a number of instances preferential etching occurred along grain boundaries; and that the degree of etching appeared to depend upon the various experimental conditions prevailing during electropolishing. These included the electrolyte composition, the average current density, and the temperature in the vicinity of the specimen. In the specific case of 70/30 brass shock-loaded at pressures in the range 200-400 kilobars, the predominant mode of deformation was observed to be twin-type faults which in several cases exhibited preferential etching similar to that observed along grain boundaries. A novel feature of this particular phenomenon was that in certain cases, especially for twins located in the vicinity of the specimen edge, the etching or preferential electropolishing literally isolated these structures from the matrix.

Site of Lysosome Production During Hepatic Injury

1969 ◽  
Vol 27 ◽  
pp. 348-349
Author(s):  
Nalin J. Unakar
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mouse Liver ◽  
Hepatic Injury ◽  
Close Approximation ◽  
Experimental Conditions ◽  
Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

Optimizing conditions for x-ray microchemical analysis in analytical electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 548-549 ◽  
Author(s):  
N. J. Zaluzec
Keyword(s):  
Solid Angle ◽  
Analytical Electron Microscopy ◽  
Incident Beam ◽  
Thin Foil ◽  
Experimental Conditions ◽  
X Ray ◽  
Microchemical Analysis ◽  
Analytical Electron ◽  
Image Position ◽  
Incident Beam Energy

The ultimate sensitivity of microchemical analysis using x-ray emission rests in selecting those experimental conditions which will maximize the measured peak-to-background (P/B) ratio. This paper presents the results of calculations aimed at determining the influence of incident beam energy, detector/specimen geometry and specimen composition on the P/B ratio for ideally thin samples (i.e., the effects of scattering and absorption are considered negligible). As such it is assumed that the complications resulting from system peaks, bremsstrahlung fluorescence, electron tails and specimen contamination have been eliminated and that one needs only to consider the physics of the generation/emission process.The number of characteristic x-ray photons (Ip) emitted from a thin foil of thickness dt into the solid angle dΩ is given by the well-known equation

SEM analysis of the change in the reaction rates with deposit structures in the copper-iron cementation system

1978 ◽  
Vol 36 (1) ◽  
pp. 456-457
Author(s):  
V. Annamalai ◽  
L.E. Murr
Keyword(s):  
Structural Characteristics ◽  
Secondary Electron Emission ◽  
Copper Deposit ◽  
Reaction Rates ◽  
Sem Analysis ◽  
Experimental Conditions ◽  
Major Drawback ◽  
Emission Mode ◽  
Scrap Iron ◽  
Image Position

Economical recovery of copper metal from leach liquors has been carried out by the simple process of cementing copper onto a suitable substrate metal, such as scrap-iron, since the 16th century. The process has, however, a major drawback of consuming more iron than stoichiometrically needed by the reaction.Therefore, many research groups started looking into the process more closely. Though it is accepted that the structural characteristics of the resultant copper deposit cause changes in reaction rates for various experimental conditions, not many systems have been systematically investigated. This paper examines the deposit structures and the kinetic data, and explains the correlations between them.A simple cementation cell along with rotating discs of pure iron (99.9%) were employed in this study to obtain the kinetic results The resultant copper deposits were studied in a Hitachi Perkin-Elmer HHS-2R scanning electron microscope operated at 25kV in the secondary electron emission mode.

Relative Intensities in ED Patterns From Thin Gold Films

1972 ◽  
Vol 30 ◽  
pp. 636-637
Author(s):  
R. H. Morriss ◽  
J. D. C. Peng ◽  
C. D. Melvin
Keyword(s):  
Theoretical Calculations ◽  
Diffraction Theory ◽  
Gold Films ◽  
Reasonable Accuracy ◽  
Experimental Conditions ◽  
Crystal Perfection ◽  
Heavy Atoms ◽  
Fine Focus ◽  
Convergent Beam ◽  
Beam Diffraction

Although dynamical diffraction theory was modified for electrons by Bethe in 1928, relatively few calculations have been carried out because of computational difficulties. Even fewer attempts have been made to correlate experimental data with theoretical calculations. The experimental conditions are indeed stringent - not only is a knowledge of crystal perfection, morphology, and orientation necessary, but other factors such as specimen contamination are important and must be carefully controlled. The experimental method of fine-focus convergent-beam electron diffraction has been successfully applied by Goodman and Lehmpfuhl to single crystals of MgO containing light atoms and more recently by Lynch to single crystalline (111) gold films which contain heavy atoms. In both experiments intensity distributions were calculated using the multislice method of n-beam diffraction theory. In order to obtain reasonable accuracy Lynch found it necessary to include 139 beams in the calculations for gold with all but 43 corresponding to beams out of the [111] zone.

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