scholarly journals Development and Evaluation of Matrices Composed of β-cyclodextrin and Biodegradable Polyesters in the Controlled Delivery of Pindolol

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 500
Author(s):  
Agnieszka Lis-Cieplak ◽  
Filip Charuk ◽  
Marcin Sobczak ◽  
Anna Zgadzaj ◽  
Agata Drobniewska ◽  
...  
Keyword(s):  
Heart Diseases ◽  
Coupling Reaction ◽  
Magic Angle Spinning ◽  
Burst Release ◽  
Magic Angle ◽  
Chemical Structures ◽  
Drug Conjugates ◽  
Flight Mass Spectrometry ◽  
Angle Spinning

Polymer-drug conjugates are currently being more widely investigated for the treatment of hypertension. In view of the above, in the first stage of our work, we used nontoxic β-cyclodextrin (β-CD) as effective, simple, inexpensive, and safe for the human body initiator for the synthesis of biocompatible and biodegradable functionalized polymers suitable for the medical and pharmaceutical applications. The obtained polymeric products were synthesized through a ring-opening polymerization (ROP) of ε-caprolactone (CL), d,l-, and l,l-lactide (LA and LLA). The chemical structures of synthesized materials were elucidated based on 1H NMR and solid-state carbon-13 cross-polarization/magic angle spinning nuclear magnetic resonance (13C CP/MAS NMR) analysis, while the incorporation of β-CD molecule into the polymer chain was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Furthermore, molecular modeling has been applied to investigate the intrachain rigidities and chain architectures for several representative structures. The obtained and thoroughly characterized branched matrices were then used to generate the first β-cyclodextrin/biodegradable polymer/β-blocker conjugate through the successful conjugation of pindolol. The conjugates were fabricated by carbodiimide-mediated coupling reaction. The branched biodegradable materials released the drug in vitro in a sustained manner and without “burst release” and thus have the ability to treat different heart diseases.

scholarly journals CHARACTERIZATION OF BULK SOIL HUMIN AND ITS ALKALINE-SOLUBLE AND ALKALINE-INSOLUBLE FRACTIONS

2015 ◽  
Vol 39 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Cuilan Li ◽  
Shuqing Gao ◽  
Qiang Gao ◽  
Lichun Wang ◽  
Jinjing Zhang
Keyword(s):  
Ph Value ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
13C Cpmas Nmr ◽  
Traditional Treatment ◽  
Chemical Structures ◽  
Exhaustive Extraction ◽  
Angle Spinning ◽  
Soil Colloids

Humic substances are the major components of soil organic matter. Among the three humic substance components (humic acid, fulvic acid, and humin), humin is the most insoluble in aqueous solution at any pH value and, in turn, the least understood. Humin has poor solubility mainly because it is tightly bonded to inorganic soil colloids. By breaking the linkage between humin and inorganic soil colloids using inorganic or organic solvents, bulk humin can be partially soluble in alkali, enabling a better understanding of the structure and properties of humin. However, the structural relationship between bulk humin and its alkaline-soluble (AS) and alkaline-insoluble (AIS) fractions is still unknown. In this study, we isolated bulk humin from two soils of Northeast China by exhaustive extraction (25 to 28 times) with 0.1 mol L-1 NaOH + 0.1 mol L-1 Na4P2O7, followed by the traditional treatment with 10 % HF-HCl. The isolated bulk humin was then fractionated into AS-humin and AIS-humin by exhaustive extraction (12 to 15 times) with 0.1 mol L-1 NaOH. Elemental analysis and solid-state 13C cross-polarization magic angle spinning nuclear magnetic resonance (13C CPMAS NMR) spectroscopy were used to characterize and compare the chemical structures of bulk humin and its corresponding fractions. The results showed that, regardless of soil types, bulk humin was the most aliphatic and most hydrophobic, AS-humin was the least aliphatic, and AIS-humin was the least alkylated among the three humic components. The results showed that bulk humin and its corresponding AS-humin and AIS-humin fractions are structurally differed from one another, implying that the functions of these humic components in the soil environment differed.

scholarly journals Targeted synthesis of electroactive porous organic frameworks containing triphenyl phosphine moieties

2013 ◽  
Vol 371 (2000) ◽  
pp. 20120312 ◽  
Author(s):  
Cuiying Pei ◽  
Teng Ben ◽  
Han Guo ◽  
Jun Xu ◽  
Feng Deng ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Magic Angle Spinning ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
Triphenyl Phosphine ◽  
Cross Coupling Reaction ◽  
Porous Aromatic Framework ◽  
Recognition Ability ◽  
Angle Spinning ◽  
Efficient Recognition

A novel electroactive porous aromatic framework (JUC-Z4-Cl) was designed and synthesized via Yamamoto-type Ullmann cross-coupling reaction with the monomer tris(4-chlorophenyl)phosphine. By simple redox chemical reactions, stable, reductive, porous polytri( p -phenyl)phosphine (JUC-Z4) and polytri( p -phenyl)phosphine oxide (JUC-Z5) could be obtained as off-white powders. The structures of JUC-Z4 and JUC-Z5 were confirmed using magic-angle spinning nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, etc. The microporous architectures exhibit high stability (471°C for JUC-Z4 and 484°C for JUC-Z5) and large surface area (793 and 648 m 2  g −1 for JUC-Z4 and JUC-Z5, respectively). JUC-Z4 also exhibits efficient recognition ability of greenhouse gases from dry air.

From Precursors to Non-Oxide Ceramics: Pyrolytic Mechanisms Studied by NMR

1995 ◽  
Vol 410 ◽  
Author(s):  
W. M. Sigmund ◽  
M. Feike ◽  
H. W. Spiess ◽  
F. Aldinger
Keyword(s):  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Inert Gas ◽  
Magic Angle ◽  
Oxide Ceramics ◽  
Cross Polarization ◽  
Chemical Structures ◽  
Angle Spinning ◽  
Cp Mas Nmr ◽  
Probe Head

ABSTRACTThe pyrolysis of a poly ethylsilazane was studied using a CO2-laser beam heated solid state MAS-NMR probe head. Chemical structures of the intermediate stages could be identified. The analogy of the pyrolysis evolution for the following two different methods could be shown: A) in an inert gas furnace conventionally prepared and B) laser irradiated in the NMR probe head under magic-angle spinning (MAS) conditions. Samples prepared by method A were studied by 29Si MAS-NMR and samples prepared by method B were studied with an appropriate cross polarization time by 29Si CP-MAS-NMR. Both experiments showed the same mechanisms for the pyrolysis as the polymer is transformed into a Si3N4/C ceramic.

scholarly journals Biodistribution of Poly(alkyl cyanoacrylate) Nanoparticles in Mice and Effect on Tumor Infiltration of Macrophages into a Patient-Derived Breast Cancer Xenograft

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1140
Author(s):  
Abhilash D. Pandya ◽  
Tore-Geir Iversen ◽  
Siver Moestue ◽  
Maria T. Grinde ◽  
Ýrr Mørch ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cellular Responses ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Therapeutic Effects ◽  
Tumor Infiltration ◽  
M1 Macrophages ◽  
Breast Cancer Xenograft ◽  
Angle Spinning

We have investigated the biodistribution and tumor macrophage infiltration after intravenous injection of the poly(alkyl cyanoacrylate) nanoparticles (NPs): PEBCA (poly(2-ethyl-butyl cyanoacrylate), PBCA (poly(n-butyl cyanoacrylate), and POCA (poly(octyl cyanoacrylate), in mice. These NPs are structurally similar, have similar PEGylation, and have previously been shown to give large variations in cellular responses in vitro. The PEBCA NPs had the highest uptake both in the patient-derived breast cancer xenograft MAS98.12 and in lymph nodes, and therefore, they are the most promising of these NPs for delivery of cancer drugs. High-resolution magic angle spinning magnetic resonance (HR MAS MR) spectroscopy did not reveal any differences in the metabolic profiles of tumors following injection of the NPs, but the PEBCA NPs resulted in higher tumor infiltration of the anti-tumorigenic M1 macrophages than obtained with the two other NPs. The PEBCA NPs also increased the ratio of M1/M2 (anti-tumorigenic/pro-tumorigenic) macrophages in the tumors, suggesting that these NPs might be used both as a vehicle for drug delivery and to modulate the immune response in favor of enhanced therapeutic effects.

scholarly journals Structural changes of TasA in biofilm formation ofBacillus subtilis

2018 ◽  
Vol 115 (13) ◽  
pp. 3237-3242 ◽  
Author(s):  
Anne Diehl ◽  
Yvette Roske ◽  
Linda Ball ◽  
Anup Chowdhury ◽  
Matthias Hiller ◽  
...  
Keyword(s):  
Structural Change ◽  
Structural Changes ◽  
Analytical Ultracentrifugation ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
X Ray ◽  
X Ray Crystallography ◽  
Angle Spinning

Microorganisms form surface-attached communities, termed biofilms, which can serve as protection against host immune reactions or antibiotics.Bacillus subtilisbiofilms contain TasA as major proteinaceous component in addition to exopolysaccharides. In stark contrast to the initially unfolded biofilm proteins of other bacteria, TasA is a soluble, stably folded monomer, whose structure we have determined by X-ray crystallography. Subsequently, we characterized in vitro different oligomeric forms of TasA by NMR, EM, X-ray diffraction, and analytical ultracentrifugation (AUC) experiments. However, by magic-angle spinning (MAS) NMR on live biofilms, a swift structural change toward only one of these forms, consisting of homogeneous and protease-resistant, β-sheet–rich fibrils, was observed in vivo. Thereby, we characterize a structural change from a globular state to a fibrillar form in a functional prokaryotic system on the molecular level.

NMR of Tissues Exposed to Polysiloxane Gels

1998 ◽  
Vol 71 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Leoncio Garrido
Keyword(s):  
Biomedical Applications ◽  
Breast Implants ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
29Si Nmr ◽  
29Si Nmr Spectra ◽  
Angle Spinning ◽  
Polysiloxane Gel

Abstract Silicone (polysiloxanes) gel-filled implants have been widely used for biomedical applications, mainly because they were considered to be nonbiodegradable. However, increasing concern about the health implications of polysiloxane exposure for women with silicone gel-filled breast implants has prompted interest to study the biochemistry of implanted polysiloxanes. The purpose of this work is to investigate the migration of polysiloxanes from the implant to local and distant sites and their chemical modification in living systems. Tissues from animals and humans exposed to polysiloxane gel implants are studied in vivo using proton NMR localized spectroscopy, and in vitro with proton and 29Si magic angle spinning (MAS) NMR spectroscopy. This work demonstrates that free polysiloxanes present in the gel-filled implants migrate to surrounding tissues and distant organs, such as the liver. In addition, 29Si NMR spectra of metabolically active tissues (liver) show the presence of chemically unchanged polysiloxanes and other silicon-containing compounds (silica) which suggest that these polymers are biodegradable.

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