scholarly journals Anomalous diffusion of Ibuprofen in cyclodextrin nanosponge hydrogels: an HRMAS NMR study

2014 ◽  
Vol 10 ◽  
pp. 2715-2723 ◽  
Author(s):  
Monica Ferro ◽  
Franca Castiglione ◽  
Carlo Punta ◽  
Lucio Melone ◽  
Walter Panzeri ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Transport Properties ◽  
Anomalous Diffusion ◽  
Pulse Sequence ◽  
Magic Angle Spinning ◽  
Random Motion ◽  
Nanoporous Structure ◽  
Magic Angle ◽  
Polymer Backbone ◽  
Hrmas Nmr

Ibuprofen sodium salt (IP) was encapsulated in cyclodextrin nanosponges (CDNS) obtained by cross-linking of β-cyclodextrin with ethylenediaminetetraacetic acid dianhydride (EDTAn) in two different preparations: CDNSEDTA 1:4 and 1:8, where the 1:n notation indicates the CD to EDTAn molar ratio. The entrapment of IP was achieved by swelling the two polymers with a 0.27 M solution of IP in D2O, leading to colourless, homogeneous hydrogels loaded with IP. The molecular environment and the transport properties of IP in the hydrogels were studied by high resolution magic angle spinning (HRMAS) NMR spectroscopy. The mean square displacement (MSD) of IP in the gels was obtained by a pulsed field gradient spin echo (PGSE) NMR pulse sequence at different observation times t d. The MSD is proportional to the observation time elevated to a scaling factor α. The α values define the normal Gaussian random motion (α = 1), or the anomalous diffusion (α < 1, subdiffusion, α > 1 superdiffusion). The experimental data here reported point out that IP undergoes subdiffusive regime in CDNSEDTA 1:4, while a slightly superdiffusive behaviour is observed in CDNSEDTA 1:8. The transition between the two dynamic regimes is triggered by the polymer structure. CDNSEDTA 1:4 is characterized by a nanoporous structure able to induce confinement effects on IP, thus causing subdiffusive random motion. CDNSEDTA 1:8 is characterized not only by nanopores, but also by dangling EDTA groups ending with ionized COO− groups. The negative potential provided by such groups to the polymer backbone is responsible for the acceleration effects on the IP anion thus leading to the superdiffusive behaviour observed. These results point out that HRMAS NMR spectroscopy is a powerful direct method for the assessment of the transport properties of a drug encapsulated in polymeric scaffolds. The diffusion properties of IP in CDNS can be modulated by suitable polymer synthesis; this finding opens the possibility to design suitable systems for drug delivery with predictable and desired drug release properties.

Exploring Helical Folding of Oligoureas During Chain Elongation by High-Resolution Magic-Angle-Spinning (HRMAS) NMR Spectroscopy

2008 ◽  
Vol 14 (13) ◽  
pp. 3874-3882 ◽  
Author(s):  
Aude Violette ◽  
Nathalie Lancelot ◽  
Alexander Poschalko ◽  
Martial Piotto ◽  
Jean-Paul Briand ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Magic Angle Spinning ◽  
Chain Elongation ◽  
Magic Angle ◽  
Hrmas Nmr ◽  
Angle Spinning ◽  
Helical Folding

scholarly journals Detection of Local Prostate Metabolites by Hrmas Nmr Spectroscopy: A Comparative Study of Human and Rat Prostate Tissues

2010 ◽  
Vol 4 ◽  
pp. MRI.S6028 ◽  
Author(s):  
Katarina Stenman ◽  
Izabella Surowiec ◽  
Henrik Antti ◽  
Katrine Riklund ◽  
Pär Stattin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magic Angle Spinning ◽  
General Distribution ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
Hrmas Nmr ◽  
Rat Prostate

The use of magnetic resonance spectroscopy (MRS) for the detection of in-vivo metabolic perturbations is increasing in popularity in Prostate Cancer (PCa) research on both humans and rodent models. However, there are distinct metabolic differences between species and prostate areas; a fact making general conclusions about PCa difficult. Here, we use High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS NMR) spectroscopy to provide tissue specific identification of metabolites and their relative ratios; information useful in providing insight into the biochemical pathways of the prostate. As our NMR-based approach reveals, human and rat prostate tissues have different metabolic signatures as reflected in numerous key metabolites, including citrate and choline compounds, but also aspartate, lysine, taurine, glutamate, glutamine, creatine and inositol. In general, distribution of these metabolites is not only highly dependent on the species (human versus rat), but also on the location (lobe/zone) in the prostate tissue and the sample pathology; an observation making HRMAS NMR of intact tissue samples a promising method for extracting differences and common features in various experimental prostate cancer models.

scholarly journals Metabolomic profile of the adrenal gland: from physiology to pathological conditions

2013 ◽  
Vol 20 (5) ◽  
pp. 705-716 ◽  
Author(s):  
Alessio Imperiale ◽  
Karim Elbayed ◽  
François-Marie Moussallieh ◽  
Nathalie Reix ◽  
Martial Piotto ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Adrenal Cortex ◽  
Metabolic Profile ◽  
Fatty Acid Content ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Tissue Samples ◽  
Medullary Tissue ◽  
Noradrenaline Secretion ◽  
Hrmas Nmr

In this study, we i) assessed the metabolic profile of the normal adrenal cortex and medulla of adult human subjects by means of1H-high-resolution magic-angle spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy; ii) compared the biochemical profile of adenoma (Ad), adrenal cortical carcinoma (ACC), and pheochromocytoma (PCC) samples with that of healthy adrenal tissue samples; and iii) investigated the metabolic differences between ACCs and Ads as well as between ACCs and PCCs. Sixty-six tissue samples (13 adrenal cortical tissue, eight medullary tissue, 13 Ad, 12 ACC, and 20 PCC samples) were analyzed. Adrenaline and noradrenaline were undetectable in cortical samples representing the metabolic signature of the tissue derived from neural crest. Similarity between the metabolic profile of Ads and that of the normal adrenal cortex was shown. Inversely, ACC samples clearly made up a detached group exhibiting the typical stigmata of neoplastic tissue such as choline-containing compounds, biochemical markers of anaerobic processes, and increased glycolysis. Significantly higher levels of lactate, acetate, and total choline-containing compounds played a major role in the differentiation of ACCs from Ads. Moreover, the high fatty acid content of ACCs contributed to the cluster identification of ACCs. Of the 14 sporadic PCC samples, 12 exhibited predominant or exclusive noradrenaline secretion. The noradrenaline:adrenaline ratio was inverted in the normal medullary tissue samples. Multiple endocrine neoplasia type 2- and NF1-related PCC samples exhibited both adrenaline and noradrenaline secretion. In the von Hippel–Lindau disease-related PCC samples, only noradrenaline secretion was detected by HRMAS NMR spectroscopy. This study is one of the first applications of metabolomics to adrenal pathophysiology and it is the largest study to report HRMAS NMR data related to the adrenal cortex and adrenal cortical tumors.

Metabolomic pattern of childhood neuroblastoma obtained by 1H-high-resolution magic angle spinning (HRMAS) NMR spectroscopy

2010 ◽  
Vol 56 (1) ◽  
pp. 24-34 ◽  
Author(s):  
Alessio Imperiale ◽  
Karim Elbayed ◽  
François-Marie Moussallieh ◽  
Agnès Neuville ◽  
Martial Piotto ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Hrmas Nmr ◽  
Angle Spinning

Wideline 2H -NMR Spectroscopy and Imaging of Solids

1994 ◽  
Vol 49 (1-2) ◽  
pp. 19-26 ◽  
Author(s):  
B. Blümich
Keyword(s):  
Nmr Spectroscopy ◽  
Excitation Power ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
2H Nmr ◽  
Stochastic Excitation ◽  
2H Nmr Spectroscopy ◽  
Spatially Inhomogeneous ◽  
Recent Developments ◽  
Angle Spinning

Abstract Recent developments, focussing on reduction of the rf excitation power by stochastic excitation, on improvements in sensitivity and excitation bandwidth by magic angle spinning, and on combining wideline spectroscopy with spatial resolution for investigations o f spatially inhomogeneous objects are reviewed.

scholarly journals Sampling Method Affects HR-MAS NMR Spectra of Healthy Caprine Brain Biopsies

Metabolites ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Annakatrin Häni ◽  
Gaëlle Diserens ◽  
Anna Oevermann ◽  
Peter Vermathen ◽  
Christina Precht
Keyword(s):  
Nmr Spectroscopy ◽  
Sampling Method ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Magic Angle ◽  
1H Nuclear Magnetic Resonance ◽  
Rapid Changes ◽  
Tissue Degradation ◽  
Angle Spinning

The metabolic profiling of tissue biopsies using high-resolution–magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy may be influenced by experimental factors such as the sampling method. Therefore, we compared the effects of two different sampling methods on the metabolome of brain tissue obtained from the brainstem and thalamus of healthy goats by 1H HR-MAS NMR spectroscopy—in vivo-harvested biopsy by a minimally invasive stereotactic approach compared with postmortem-harvested sample by dissection with a scalpel. Lactate and creatine were elevated, and choline-containing compounds were altered in the postmortem compared to the in vivo-harvested samples, demonstrating rapid changes most likely due to sample ischemia. In addition, in the brainstem samples acetate and inositols, and in the thalamus samples ƴ-aminobutyric acid, were relatively increased postmortem, demonstrating regional differences in tissue degradation. In conclusion, in vivo-harvested brain biopsies show different metabolic alterations compared to postmortem-harvested samples, reflecting less tissue degradation. Sampling method and brain region should be taken into account in the analysis of metabolic profiles. To be as close as possible to the actual situation in the living individual, it is desirable to use brain samples obtained by stereotactic biopsy whenever possible.

Pulsed Field Gradient Selection in Two-Dimensional Magic Angle Spinning NMR Spectroscopy of Dipolar Solids

1998 ◽  
Vol 134 (2) ◽  
pp. 355-359 ◽  
Author(s):  
Tilo Fritzhanns ◽  
Siegfried Hafner ◽  
Dan E. Demco ◽  
Hans W. Spiess ◽  
Frank H. Laukien
Keyword(s):  
Nmr Spectroscopy ◽  
Field Gradient ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Two Dimensional ◽  
Pulsed Field ◽  
Angle Spinning
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