3D-Printed Gastroretentive Tablets Loaded with Niclosamide Nanocrystals by the Melting Solidification Printing Process (MESO-PP).

Niclosamide (NICLO) is a recognized antiparasitic drug being repositioned for Helicobacter pylori. The present work aimed to formulate NICLO nanocrystals (NICLO-NCRs) to produce a higher dissolution rate of the active ingredient and to incorporate these nanosystems into a floating solid dosage form to release them into the stomach slowly. For this purpose, NICLO-NCRs were produced by wet-milling and included in a floating Gelucire l3D printed tablet by semi-solid extrusion, applying the Melting solidification printing process (MESO-PP) methodology. The results obtained in TGA, DSC, XRD and FT-IR analysis showed no physicochemical interactions or modifications in the crystallinity of NICLO-NCR after inclusion in Gelucire 50/13 ink. This method allowed the incorporation of NICLO-NCRs in a concentration of up to 25% w/w. It achieved a controlled release of NCRs in a simulated gastric medium. Moreover, the presence of NICLO-NCRs after redispersion of the printlets was observed by STEM. Additionally, no effects on the cell viability of the NCRs were demonstrated in the GES-1 cell line. Finally, gastroretention was demonstrated for 180 min in dogs. These findings show the potential of the MESO-PP technique in obtaining slow-release gastro-retentive oral solid dosage forms loaded with nanocrystals of a poorly soluble drug, an ideal system for treating gastric pathologies such as H. pylori.

Low nanomolar concentrations of a quercetin oxidation product, which naturally occurs in onion peel, protect cells against oxidative damage.

The occurrence of the quercetin oxidation metabolite 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (BZF), whose antioxidant potency is notably higher than the antioxidant potency of quercetin, was investigated in twenty quercetin-rich plant foods. BZF was identified (HPLC-DAD-ESI-MS/MS) only in the dry outer scales of onions and shallots. Aqueous extracts of onions (OAE) and shallots (SAE) were evaluated for their antioxidant and cytoprotective properties. OAE, whose potency did not differ from SAE, protected ROS-exposed Caco2 cells against oxidative (78%) and cellular (90%) damage at a 3 µg/L concentration (corresponding to 0.03 nM of BZF). After chromatographic resolution of OAE, the BZF peak accounted fully and exclusively for its antioxidant effect. The antioxidant effects of OAE and of a pure BZF were described by two perfectly overlapping curves whose concentration-dependence was within the 3 × 10-4 to 102 nM BZF range. Such unprecedented low concentrations place BZF-containing plants on the frontier of the search for novel sources of antioxidants.

Ni/Ni oxides nanoparticles with potential biomedical applications obtained by displacement of a nickel-organometallic complex.

A new synthesis and stabilization method was developed for paramagnetic nanoparticles composed of nickel and nickel oxides. Nickel/nickel oxides nanoparticles were synthesized by a method based on ligand displacement of bis(1,5-cyclooctadiene)-nickel(0), zerovalent organometallic precursor and simultaneous formation of a thiourea inclusion compound. Nickel/nickel oxides nanoparticles were stabilized with the amphipathic peptide H2N-Cys-Leu-Pro-Phe-Phe-Asp-NH2 having H2N-Leu-Pro-Phe-Phe-Asp-NH2 a peptide with potential properties for Alzheimer's disease therapy. The inclusion compound formed after displacement was characterized by X-ray powder diffraction, and nickel/nickel oxides nanoparticles were characterized using transmission electron microscopy, atomic force microscopy, UV-Visible spectroscopy, X-ray photoelectron spectroscopy, and superconducting quantum interference device magnetometry. In addition, a cell viability assay in primary rat hippocampal neurons was carried out.

Improving gold nanorod delivery to the central nervous system by conjugation to the shuttle Angiopep-2.

AIM: To improve the in vivo delivery of gold nanorods (GNRs) to the central nervous system of rats, these gold nanoparticles were conjugated to Angiopep-2, a shuttle peptide that can cross the blood-brain barrier. MATERIALS & METHODS: GNRs were synthesized and modified using polyethylene glycol and Angiopep-2 (GNR-PEG-Angiopep-2). The physicochemical properties, in vitro cytotoxicity and ex vivo biodistribution of the conjugate were examined. RESULTS: GNR-PEG-Angiopep-2 was stable over the following days, and the different concentrations that were tested did not affect the viability of microvascular endothelial cells. The conjugation of Angiopep-2 to GNRs enhanced the endocytosis of these particles (in vitro) and the accumulation in brains (in vivo), when compared with GNRs modified only with PEG. CONCLUSION: This study provides evidence that Angiopep-2 improves the delivery of GNRs to the brain parenchyma. This property is highly relevant for future applications of GNRs as platforms for photothermal and theranostic purposes.