scholarly journals Stabilization by Nano Spray Dryer of Pioglitazone Polymeric Nanosystems: Development, In Vivo, Ex Vivo and Synchrotron Analysis

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1751
Author(s):  
Marcelle Silva-Abreu ◽  
Esther Miralles ◽  
Christina S. Kamma-Lorger ◽  
Marta Espina ◽  
Maria Luisa García ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Physicochemical Characteristics ◽  
Spray Dryer ◽  
Drying Process ◽  
X Ray ◽  
X Ray Scattering ◽  
Before And After ◽  
Saxs Analysis ◽  
Corneal Collagen

Pioglitazone-loaded PLGA-PEG nanoparticles (NPs) were stabilized by the spray drying technique as an alternative to the treatment of ocular inflammatory disorders. Pioglitazone-NPs were developed and characterized physiochemically. Interaction studies, biopharmaceutical behavior, ex vivo corneal and scleral permeation, and in vivo bioavailability evaluations were conducted. Fibrillar diameter and interfibrillar corneal spacing of collagen was analyzed by synchrotron X-ray scattering techniques and stability studies at 4 °C and was carried out before and after the spray drying process. NPs showed physicochemical characteristics suitable for ocular administration. The release was sustained up to 46 h after drying; ex vivo corneal and scleral permeation profiles of pioglitazone-NPs before and after drying demonstrated higher retention and permeation through cornea than sclera. These results were correlated with an in vivo bioavailability study. Small-angle X-ray scattering (SAXS) analysis did not show a significant difference in the organization of the corneal collagen after the treatment with pioglitazone-NPs before and after the drying process, regarding the negative control. The stabilization process by Nano Spray Dryer B-90 was shown to be useful in preserving the activity of pioglitazone inside the NPs, maintaining their physicochemical characteristics, in vivo bioavailability, and non-damage to corneal collagen function after SAXS analysis was observed.

scholarly journals Pilot study on the effects of preservatives on corneal collagen parameters measured by small angle X-ray scattering analysis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Susyn Joan Kelly ◽  
Lizette duPlessis ◽  
John Soley ◽  
Frazer Noble ◽  
Hannah Carolyn Wells ◽  
...  
Keyword(s):  
Small Angle ◽  
Collagen Fibril ◽  
Diameter Distribution ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Analysis ◽  
Triton X ◽  
Fibril Diameter ◽  
Corneal Collagen ◽  
Ray Scattering

Abstract Objective Small angle X-ray scattering (SAXS) analysis is a sensitive way of determining the ultrastructure of collagen in tissues. Little is known about how parameters measured by SAXS are affected by preservatives commonly used to prevent autolysis. We determined the effects of formalin, glutaraldehyde, Triton X and saline on measurements of fibril diameter, fibril diameter distribution, and D-spacing of corneal collagen using SAXS analysis. Results Compared to sections of sheep and cats’ corneas stored frozen as controls, those preserved in 5% glutaraldehyde and 10% formalin had significantly larger mean collagen fibril diameters, increased fibril diameter distribution and decreased D-spacing. Sections of corneas preserved in Triton X had significantly increased collagen fibril diameters and decreased fibril diameter distribution. Those preserved in 0.9% saline had significantly increased mean collagen fibril diameters and decreased diameter distributions. Subjectively, the corneas preserved in 5% glutaraldehyde and 10% formalin maintained their transparency but those in Triton X and 0.9% saline became opaque. Subjective morphological assessment of transmission electron microscope images of corneas supported the SAXS data. Workers using SAXS analysis to characterize collagen should be alerted to changes that can be introduced by common preservatives in which their samples may have been stored.

scholarly journals Effects of Preservatives on Corneal Collagen Parameters Measured by Small Angle X-Ray Scattering Analysis

2020 ◽  
Author(s):  
Susyn Kelly ◽  
Lizette duPlessis ◽  
John Soley ◽  
Frazer Noble ◽  
Hannah Carolyn Wells ◽  
...  
Keyword(s):  
Small Angle ◽  
Collagen Fibril ◽  
Diameter Distribution ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Analysis ◽  
Triton X ◽  
Fibril Diameter ◽  
Corneal Collagen ◽  
Ray Scattering

Abstract Objective: Small angle X-ray scattering (SAXS) analysis is a sensitive method for determining the ultrastructure of collagen in various tissues. Little is known about how parameters measured by SAXS are affected by preservatives, commonly used to prevent autolysis and strengthen sample tissues. We determined the effects of formalin, glutaraldehyde, Triton X and saline on measurements of fibril diameter, fibril diameter distribution, and D-spacing of corneal collagen using SAXS analysis. Results: Compared to control sheep and cats’ corneas, frozen at -80 °C, those preserved in 5% glutaraldehyde and 10% formalin had significantly larger mean collagen fibril diameters, increased fibril diameter distribution and decreased D-spacing. Corneas preserved in Triton X had significantly increased collagen fibril diameters and decreased fibril diameter distribution. Corneas preserved in 0.9% saline had significantly increased mean collagen fibril diameters and decreased diameter distributions. Subjectively, the corneas preserved in 5% glutaraldehyde and 10% formalin maintained their transparency but those in Triton X and 0.9% saline became opaque. Subjective morphological assessment of transmission electron microscope images of corneas supported the SAXS data. Workers using SAXS analysis to characterize collagen should be alerted to changes that can be introduced by common preservatives in which their samples may have been stored.

scholarly journals Effects of Preservatives on Corneal Collagen Parameters Measured by Small Angle X-ray Scattering Analysis

2020 ◽  
Author(s):  
Susyn Kelly ◽  
Lizette duPlessis ◽  
John Soley ◽  
Frazer Noble ◽  
Hannah Catherine Wells ◽  
...  
Keyword(s):  
Small Angle ◽  
Collagen Fibril ◽  
Diameter Distribution ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Analysis ◽  
Triton X ◽  
Fibril Diameter ◽  
Corneal Collagen ◽  
Ray Scattering

Abstract Background: Collagen is a prominent structural protein in biological tissue, and little is known about the effect of preservatives, commonly used to preserve and study tissue, on collagen structures. Method: The study determined the effects of commonly used tissue preservatives on measurements of fibril diameter, fibril diameter distribution, and D-spacing of corneal collagen made using small angle X-ray scattering (SAXS) analysis. Results: Compared to control sheep and cats’ corneas that were preserved frozen at -80 °C, those preserved in 5% glutaraldehyde and 10% formalin had significantly larger mean collagen fibril diameters, increased fibril diameter distribution and decreased D-spacing. Corneas preserved in Triton X had significantly increased mean collagen fibril diameters and orientation indexes with decreased fibril diameter distribution. Corneas preserved in 0.9% saline had significantly increased mean collagen fibril diameters and decreased diameter distributions. Subjectively, the corneas preserved in 5% glutaraldehyde and 10% formalin maintained their transparency but those in Triton X and 0.9% saline became opaque. Subjective morphological assessment of transmission electron microscope images of corneas supported the SAXS data. Conclusions: Workers using SAXS analysis to characterize collagen should be alerted to changes that can be introduced by common preservatives in which their samples may have been stored.

Possibilities and limits of X-ray microtomography for in vivo and ex vivo detection of vascular calcifications

2009 ◽  
Vol 25 (6) ◽  
pp. 615-624 ◽  
Author(s):  
A. A. Postnov ◽  
P. C. D’Haese ◽  
E. Neven ◽  
N. M. De Clerck ◽  
V. P. Persy
Keyword(s):  
Ex Vivo ◽  
Vascular Calcifications ◽  
X Ray

scholarly journals Exploring the in meso crystallization mechanism by characterizing the lipid mesophase microenvironment during the growth of single transmembrane α-helical peptide crystals

2016 ◽  
Vol 374 (2072) ◽  
pp. 20150125 ◽  
Author(s):  
Leonie van 't Hag ◽  
Konstantin Knoblich ◽  
Shane A. Seabrook ◽  
Nigel M. Kirby ◽  
Stephen T. Mudie ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Self Assembly ◽  
Lamellar Phase ◽  
Cubic Phase ◽  
Supporting Evidence ◽  
X Ray ◽  
X Ray Scattering ◽  
Standard Procedures ◽  
Helical Peptide ◽  
Saxs Analysis

The proposed mechanism for in meso crystallization of transmembrane proteins suggests that a protein or peptide is initially uniformly dispersed in the lipid self-assembly cubic phase but that crystals grow from a local lamellar phase, which acts as a conduit between the crystal and the bulk cubic phase. However, there is very limited experimental evidence for this theory. We have developed protocols to investigate the lipid mesophase microenvironment during crystal growth using standard procedures readily available in crystallography laboratories. This technique was used to characterize the microenvironment during crystal growth of the DAP12-TM peptide using synchrotron small angle X-ray scattering (SAXS) with a micro-sized X-ray beam. Crystal growth was found to occur from the gyroid cubic mesophase. For one in four crystals, a highly oriented local lamellar phase was observed, providing supporting evidence for the proposed mechanism for in meso crystallization. A new observation of this study was that we can differentiate diffraction peaks from crystals grown in meso , from peaks originating from the surrounding lipid matrix, potentially opening up the possibility of high-throughput SAXS analysis of in meso grown crystals. This article is part of the themed issue ‘Soft interfacial materials: from fundamentals to formulation’.

scholarly journals REGALS: a general method to deconvolve X-ray scattering data from evolving mixtures

2020 ◽  
Author(s):  
Steve P. Meisburger ◽  
Da Xu ◽  
Nozomi Ando
Keyword(s):  
A Priori ◽  
Scattering Data ◽  
Biological Macromolecules ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Open Source Software Package ◽  
Saxs Analysis ◽  
Structural Methods ◽  
Ray Scattering

AbstractMixtures of biological macromolecules are inherently difficult to study using structural methods, as increasing complexity presents new challenges for data analysis. Recently, there has been growing interest in studying evolving mixtures using small-angle X-ray scattering (SAXS) in conjunction with time-resolved, high-throughput, or chromatography-coupled setups. Deconvolution and interpretation of the resulting datasets, however, are nontrivial when neither the scattering components nor the way in which they evolve are known a priori. To address this issue, we introduce the REGALS method (REGularized Alternating Least Squares), which incorporates simple expectations about the data as prior knowledge and utilizes parameterization and regularization to provide robust deconvolution solutions. The restraints used by REGALS are general properties such as smoothness of profiles and maximum dimensions of species, which makes it well-suited for exploring datasets with unknown species. Here we apply REGALS to analyze experimental data from four types of SAXS experiment: anion-exchange (AEX) coupled SAXS, ligand titration, time-resolved mixing, and time-resolved temperature jump. Based on its performance with these challenging datasets, we anticipate that REGALS will be a valuable addition to the SAXS analysis toolkit and enable new experiments. The software is implemented in both MATLAB and python and is available freely as an open-source software package.

scholarly journals In Situ Synchrotron X-ray Study of the Mechanical Properties of Pure Mg Produced by Powder Metallurgy

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1198
Author(s):  
Li Li ◽  
Leyun Wang ◽  
Jie Wang ◽  
Huan Zhang ◽  
Qingchun Zhu ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Tensile Deformation ◽  
Line Broadening ◽  
X Ray ◽  
X Ray Scattering ◽  
Type Dislocation ◽  
Diffraction Patterns ◽  
Saxs Analysis ◽  
Ray Scattering

In this study, in situ synchrotron X-ray experiments with wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) detectors were performed on two pure magnesium materials produced by powder metallurgy. According to SAXS analysis, each of the two materials has a porosity of less than 0.5%. Line broadening analysis was performed on diffraction patterns collected by WAXS to analyze the dislocation evolution during material deformation. In both materials, <a>-type dislocation activities dominate the tensile deformation. The influence of grain size and texture on the different tensile behaviors of these two materials is also discussed.

scholarly journals Brain Tissue Conductivity Measurements with MR-Electrical Properties Tomography: An In Vivo Study

2020 ◽  
Author(s):  
Stefano Mandija ◽  
Petar I. Petrov ◽  
Jord J. T. Vink ◽  
Sebastian F. W. Neggers ◽  
Cornelis A. T. van den Berg
Keyword(s):  
Electrical Properties ◽  
Healthy Subjects ◽  
Ex Vivo ◽  
Simulated Data ◽  
Ground Truth ◽  
In Vivo Study ◽  
Conductivity Measurements ◽  
Tissue Conductivity ◽  
Before And After

AbstractFirst in vivo brain conductivity reconstructions using Helmholtz MR-Electrical Properties Tomography (MR-EPT) have been published. However, a large variation in the reconstructed conductivity values is reported and these values differ from ex vivo conductivity measurements. Given this lack of agreement, we performed an in vivo study on eight healthy subjects to provide reference in vivo brain conductivity values. MR-EPT reconstructions were performed at 3 T for eight healthy subjects. Mean conductivity and standard deviation values in the white matter, gray matter and cerebrospinal fluid (σWM, σGM, and σCSF) were computed for each subject before and after erosion of regions at tissue boundaries, which are affected by typical MR-EPT reconstruction errors. The obtained values were compared to the reported ex vivo literature values. To benchmark the accuracy of in vivo conductivity reconstructions, the same pipeline was applied to simulated data, which allow knowledge of ground truth conductivity. Provided sufficient boundary erosion, the in vivo σWM and σGM values obtained in this study agree for the first time with literature values measured ex vivo. This could not be verified for the CSF due to its limited spatial extension. Conductivity reconstructions from simulated data verified conductivity reconstructions from in vivo data and demonstrated the importance of discarding voxels at tissue boundaries. The presented σWM and σGM values can therefore be used for comparison in future studies employing different MR-EPT techniques.

scholarly journals Single-cell resolution in high-resolution synchrotron X-ray CT imaging with gold nanoparticles

2013 ◽  
Vol 21 (1) ◽  
pp. 242-250 ◽  
Author(s):  
Elisabeth Schültke ◽  
Ralf Menk ◽  
Bernd Pinzer ◽  
Alberto Astolfo ◽  
Marco Stampanoni ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Single Cell ◽  
Brain Tumour ◽  
Ex Vivo ◽  
Small Animal ◽  
C6 Glioma Cells ◽  
X Ray ◽  
Local Tomography ◽  
The Brain

Gold nanoparticles are excellent intracellular markers in X-ray imaging. Having shown previously the suitability of gold nanoparticles to detect small groups of cells with the synchrotron-based computed tomography (CT) technique bothex vivoandin vivo, it is now demonstrated that even single-cell resolution can be obtained in the brain at leastex vivo. Working in a small animal model of malignant brain tumour, the image quality obtained with different imaging modalities was compared. To generate the brain tumour, 1 × 105C6 glioma cells were loaded with gold nanoparticles and implanted in the right cerebral hemisphere of an adult rat. Raw data were acquired with absorption X-ray CT followed by a local tomography technique based on synchrotron X-ray absorption yielding single-cell resolution. The reconstructed synchrotron X-ray images were compared with images obtained by small animal magnetic resonance imaging. The presence of gold nanoparticles in the tumour tissue was verified in histological sections.

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