Silver nanoparticles augment releasing of pyrogenic factors by blood cells stimulated with LPS

Preparation, Characterization, in-vitro and in-vivo Pharmacokinetic Evaluation of Thermostable Dimethyl Fumarate Cocrystals

Dimethyl fumarate (DMF) is an FDA-approved drug for treating relapsing-remitting multiple sclerosis; but it is susceptible to sublimation leading to its loss during processing. Cocrystals can protect against thermal energy via the interaction of DMF with a coformer via weak forces of interaction. With this hypothesis, we have, for the first time, prepared DMF cocrystals using the solvent evaporation method using coformers like citric acid and succinic acid screened by in-silico predictions and hydrogen bonding properties. Analysis using infra-red (IR), powder x-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and sublimation evaluation characterized cocrystals and their thermostability. Comparative analysis of the release profile has been done by dissolution and pharmacokinetic study of DMF and its cocrystals. The cocrystals have improved thermal stability and better pharmacological activities than DMF. In the safety and efficacy evaluation of the formulated cocrystals, they were found to be non-cytotoxic, antioxidant, and inhibiting IL-6 and TNF-α in PBMC induced by lipopolysaccharide (LPS). We have obtained cocrystals of DMF with improved thermal stability and better pharmacological activities than DMF.

Novel Gastroprotective and Thermostable Cocrystal of Dimethyl Fumarate: Its Preparation, Characterization, and In Vitro and In Vivo Evaluation

Crystallization has revolutionized the field of solid-state formulations by modulating the physiochemical and release profile of active pharmaceutical ingredients (APIs). Dimethyl fumarate (DF), an FDA-approved first-line drug for relapsing-remitting multiple sclerosis, has a sublimation problem, leading to loss of the drug during its processing. To tackle this problem, DF cocrystal has been prepared by using solvent evaporation technique using nicotinamide as a coformer, which has been chosen based on in silico predictions and their ability to participate in hydrogen bonding. Fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and sublimation analysis have characterized the cocrystal and its thermostability. Comparative analysis of the release profile has been done by the dissolution and pharmacokinetic study of DF and its cocrystal. Formulated cocrystal is noncytotoxic, antioxidant and inhibits interleukin-6 and tissue necrosis factor-α in peripheral blood mononuclear cells induced by lipopolysaccharide. We have obtained a thermostable cocrystal of DF with a similar physicochemical and release profile to that of DF. The formulated cocrystal also provides a gastroprotective effect which helps counterbalance the adverse effects of DF by reducing lipid peroxidation and total nitrite levels.

Characterization, bio-uptake and toxicity of polymer-coated silver nanoparticles and their interaction with human peripheral blood mononuclear cells

Silver nanoparticles (AgNPs) are widely used in medical applications due to their antibacterial and antiviral properties. Despite the extensive study of AgNPs, their toxicity and their effect on human health is poorly understood, as a result of issues such as poor control of NP properties and lack of proper characterization. The aim of this study was to investigate the combined characterization, bio-uptake, and toxicity of well-characterized polyvinylpyrrolidone (PVP)-coated AgNPs in exposure media during exposure time using primary human cells (peripheral blood mononuclear cells (PBMCs)). AgNPs were synthesized in-house and characterized using a multimethod approach. Results indicated the transformation of NPs in RPMI medium with a change in size and polydispersity over 24 h of exposure due to dissolution and reprecipitation. No aggregation of NPs was observed in the RPMI medium over the exposure time (24 h). A dose-dependent relationship between PBMC uptake and Ag concentration was detected for both AgNP and AgNO₃ treatment. There was approximately a two-fold increase in cellular Ag uptake in the AgNO₃ vs the NP treatment. Cytotoxicity, using LDH and MTS assays and based on exposure concentrations was not significantly different when comparing NPs and Ag ions. Based on differential uptake, AgNPs were more toxic after normalizing toxicity to the amount of cellular Ag uptake. Our data highlights the importance of correct synthesis, characterization, and study of transformations to obtain a better understanding of NP uptake and toxicity. Statistical analysis indicated that there might be an individual variability in response to NPs, although more research is required.

Biocompatibility of Titania Nanotube Coatings Enriched with Silver Nanograins by Chemical Vapor Deposition

Bioactivity investigations of titania nanotube (TNT) coatings enriched with silver nanograins (TNT/Ag) have been carried out. TNT/Ag nanocomposite materials were produced by combining the electrochemical anodization and chemical vapor deposition methods. Fabricated coatings were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The release effect of silver ions from TNT/Ag composites immersed in bodily fluids, has been studied using inductively coupled plasma mass spectrometry (ICP-MS). The metabolic activity assay (MTT) was applied to determine the L929 murine fibroblasts adhesion and proliferation on the surface of TNT/Ag coatings. Moreover, the results of immunoassays (using peripheral blood mononuclear cells-PBMCs isolated from rats) allowed the estimation of the immunological activity of TNT/Ag surface materials. Antibacterial activity of TNT/Ag coatings with different morphological and structural features was estimated against two Staphylococcus aureus strains (ATCC 29213 and H9). The TNT/Ag nanocomposite layers produced revealed a good biocompatibility promoting the fibroblast adhesion and proliferation. A desirable anti-biofilm activity against the S. aureus reference strain was mainly noticed for these TiO₂ nanotube coatings, which contain dispersed Ag nanograins deposited on their surface.