scholarly journals TEMPO-Nanocellulose/Ca2+ Hydrogels: Ibuprofen Drug Diffusion and In Vitro Cytocompatibility

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 183 ◽  
Author(s):  
Andrea Fiorati ◽  
Nicola Contessi Negrini ◽  
Elena Baschenis ◽  
Lina Altomare ◽  
Silvia Faré ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Cellulose Nanofibers ◽  
Rheological Behaviour ◽  
Fibroblast Cell ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Bivalent Cation ◽  
Murine Fibroblast ◽  
Angle Spinning

Stable hydrogels with tunable rheological properties were prepared by adding Ca2+ ions to aqueous dispersions of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized and ultra-sonicated cellulose nanofibers (TOUS-CNFs). The gelation occurred by interaction among polyvalent cations and the carboxylic units introduced on TOUS-CNFs during the oxidation process. Both dynamic viscosity values and pseudoplastic rheological behaviour increased by increasing the Ca2+ concentration, confirming the cross-linking action of the bivalent cation. The hydrogels were proved to be suitable controlled release systems by measuring the diffusion coefficient of a drug model (ibuprofen, IB) by high-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy. IB was used both as free molecule and as a 1:1 pre-formed complex with β-cyclodextrin (IB/β-CD), showing in this latter case a lower diffusion coefficient. Finally, the cytocompatibility of the TOUS-CNFs/Ca2+ hydrogels was demonstrated in vitro by indirect and direct tests conducted on a L929 murine fibroblast cell line, achieving a percentage number of viable cells after 7 days higher than 70%.

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 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.

In Vitro Biodegradability of Chitosan-Organosiloxane Hybrid Membrane

2005 ◽  
Vol 284-286 ◽  
pp. 823-826 ◽  
Author(s):  
Kanji Tsuru ◽  
Yuki Shirosaki ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka ◽  
M.A. Lopes ◽  
...  
Keyword(s):  
Sol Gel ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Hybrid Membranes ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Angle Spinning ◽  
Phosphate Buffered Saline ◽  
Epoxy Groups

Chitosan-silicate hybrid membranes were prepared using g-glycidoxy-propyltrimethoxysilane (GPSM) through a sol-gel process. The amino groups of chitosan chains were reacted with the epoxy groups of GPSM and GPSM have a function as the agent to cross-link the chitosan chains. The cross-linking degree of the hybrid membranes was determined by ninhydrin assay. Fourier-transform infrared (FT-IR) spectroscopy and 29Si cross-polarization (CP) magic-angle spinning (MAS)-NMR spectroscopy were used to assess the structure of the hybrid membranes. The biodegradability of the hybrid membranes in phosphate-buffered saline solution or lysozyme solution was investigated as a function of the GPSM concentration.

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