Preparation of Prussian Blue Containing Polymeric Nanocapsule via Interfacial Confined Coordination in Crosslinked Inverse Miniemulsion

Phytoconstituent analysis, anti-inflammatory, antimicrobial and anticancer effects of nano encapsulated Convolvulus arvensis L. extracts

BACKGROUND

The Convolvulus genus is distributed all over the world and has a long history in traditional medicine. As nanotechnology expands its reach into areas like drug delivery and biomedicine, this study intends to assess the potential of Convolvulus arvensis L. extracts as anti-bacterial, anti-inflammatory and anti-cancer agents, along with chemical profiling of the methanolic (MeOH) extract active ingredients.

METHODS

The chemical composition of an 85% MeOH extract was investigated by liquid chromatography with an electrospray source connected to mass spectrometry (LC-ESI-MS). Both the 85% MeOH extract and n-butanol fraction of C. arvensis were loaded for the first time on alginate/chitosan nanoparticles. The 85% MeOH extract, n-butanol fraction and their loaded nanoparticles were tested for their cytotoxicity, anticancer, anti-inflammatory and antibacterial activity (against pathogenic bacteria, E. coli and S. aureus).

RESULTS

The chemical investigation of 85% MeOH extract of C. arvensis underwent LC-ESI-MS analysis, revealing twenty-six phenolic substances, of which 16 were phenolic acids, 6 were flavonoids, 1 glycolipid, 1 sesquiterpene and 2 unknown compounds. The FT-IR spectra confirmed the encapsulation of the 85% MeOH extract and n-butanol fraction onto alginate/chitosan nanoparticles and small size obtained by TEM maintained them nontoxic and enhanced their anti-inflammatory activity (the IC50 was decreased from 1050 to 175 µg/ml). The anti-cancer activity against HepG2 was increased and the cell viability was decreased from 28.59 ± 0.52 to 20.80 ± 0.27 at a maximum concentration of 1000 µg/ml. In addition, the MIC of encapsulated extracts was decreased from 31.25 to7.78 µg/ml in E. coli (Gm-ve) and from 15.56 to 7.78 µg/ml in S. aureus (Gm + ve) bacteria.

CONCLUSION

Both alginate and chitosan are excellent natural polymers for the encapsulation process, which affects positively on the bioactive constituents of C. arvensis extracts and improves their biological properties.

Nitrocellulose membranes in situ grown with Prussian blue nanoparticles as stable nanozyme pads for colorimetric detection of dopamine

Prussian blue (PB) is a typical peroxidase mimic with simple preparation, low cost and high eco-friendliness, but it still has drawbacks of poor stability (e.g., decomposition in aqueous dispersions) and intrinsic optical interference (e.g., high extinction coefficient over a wide wavelength range) in colorimetric assays. Herein, we used nitrocellulose (NC) membranes as synthesis hosts of PB nanoparticles (NPs) to develop a new type of three-dimensional (3D) porous nanozyme pad. By means of an in situ synthesis route, PB NPs were uniformly grown on the surfaces of the fiber scaffolds with desirable stability, which also avoided signal interference from PB NPs owing to the easy handling of the pads in a quantitative solid state. The pads showed significant peroxidase-mimicking activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) with the output of colorimetric signals. Based on the reduction of oxidized TMB (oxTMB) by dopamine (DA), the pads were exploited for simple and quantitative colorimetric detection of DA with a limit of detection (LOD) of 0.59 μM and a satisfactory accuracy for analysis of real human urine samples. This is the first attempt at exploiting NC membranes as the synthesis hosts to develop nanozyme pads, which solves the above drawbacks of traditional PB-based peroxidase mimics and has promise for various colorimetric bioanalyses, given the structural benefits of NC membranes and their broad applications in biosensors.

Investigation of Nanostructure and Interactions in Water-in-Xylene Microemulsions Using Small-Angle X-ray and Neutron Scattering

The ability to modulate the size, the nanostructure, and the macroscopic properties of water-in-oil microemulsions is useful for a variety of technological scenarios. To date, diverse structures of water-in-alkane microemulsions stabilized by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) have been extensively studied. Even though the decisive parameter which dictates the phase behavior of micremulsions is the nature of the continuous phase, relatively very few reports are available on the structure and interactions in the microemulsions of aromatic oil. Here, we present a fundamental investigation on water-in-xylene microemulsions using small-angle neutron scattering (SANS) at a fixed molar ratio (ω) of water to AOT. We elucidate the microstructural changes in the water-AOT-xylene ternary system at dilute volume fractions (Φ = 0.005, 0.01, 0.03), where the droplet-droplet interactions are absent, to moderately concentrated systems (Φ = 0.05, 0.10, 0.15, and 0.20), where colloidal interactions become important. We also characterize the reverse microemulsions (RMs) for thermally induced microstructural changes at six different temperatures from 20 to 50 °C. Depending on the magnitude of Φ, the scattering data is found to be well described by considering the RMs as a dispersion of droplets (with a Schulz polydispersity) which interact as sticky hard spheres. We show that while the droplet diameter remains almost constant with increase in the volume fraction, the attractive interactions become prominent, much like the trends observed for water-in-alkane microemulsions. With increase in temperature, the RMs showed a marginal decrease in the droplet size but no pronounced dependence on the interactions was observed with the overall structure remaining intact. The fundamental study on a model system presented in this work is key to understanding the phase behavior of multiple component microemulsions as well as their design for applications at higher temperatures, where the structure of most RMs breaks down.