Mass production of morin-stabilized silver nanoparticles: Characterization, antioxidant, and antimicrobial activities.

Phytochemical-conjugated silver nanoparticles (AgNPs) are believed to act as a bridge between nanotechnology and therapy. There is a significant need for green and mass production of such materials due to their extensive applications, especially in the biomedical sector. In this study, morin-stabilized silver nanoparticles (morin/AgNPs) were synthesized on a massive scale using a one-pot solid-state technique. The reaction is achieved by ball milling of morin and silver nitrate powders at ambient temperature without any solvent or toxic reagent. The prepared morin/AgNPs exhibited a semi-hexagonal shape and ranged in size from 21 to 43 nm. The x-ray diffraction results elucidated the formation of highly crystalline AgNPs. Fourier transform infrared and x-ray photoelectron spectroscopic analyses prove that the hydroxyl, carbonyl, and aromatic functionalities in morin are playing major roles in the reduction and stabilization of AgNPs. The antioxidant potential of morin/AgNPs was evaluated utilizing 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) assay. Morin/AgNPs exhibited better free radical scavenging activity (IC50 = 11.7 µg/mL) than morin (IC50 = 14.8 µg/mL). Furthermore, the synthesized AgNPs showed promising antimicrobial activity against Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus mutans, and Candida albicans. The largest inhibition zones were observed against S. aureus (21.2 ± 0.6 mm) and K. pneumonia (20.3 ± 0.5 mm) bacteria. The foregoing results highlighted the prospective application of morin/AgNPs as a promising antioxidant and antimicrobial material for safe medical applications. RESEARCH HIGHLIGHTS: A simple green route for the large-scale production of AgNPs was developed. Morin acts as reducing/stabilizing agent in solid-state synthesis of AgNPs. Morin/AgNPs exhibited promising antimicrobial and antioxidant activity.

Garlic peel as promising low-cost support for the cobalt nanocatalyst; synthesis and catalytic studies.

The development of cost-effective and applied catalysts for organic pollutants degradation is the cornerstone for the future valorizations of these hazardous wastes. Garlic peel was employed as solid support for the assembly of cobalt nanoparticles and was further applied for the catalytic degradation of 4-nitrophenol, bromophenol blue, and a mixture of both. A Cobalt@garlic peel nanocomposite with the morphology of semi-spherical and randomly distributed nanoparticles was prepared without the aid of any hazardous chemicals. The functional groups facilitated the adsorption of cobalt ions onto the surface of garlic peel through van der Waals forces and/or hydrogen bonds. The catalytic experiments were carried out under different operational parameters including pollutant concentration, catalytic dosage, and pH value to identify the optimal conditions for the model solutions. The results showed that the optimal pH for 4-nitrophenol degradation was around 9 and the maximum rate constant 4.56 × 10-3 sec-1. The most prominent feature of the proposed catalyst is the easy/efficient recovery and recycling of the nanoparticles from the reacting medium. This work provided a simple method for designing other similar biomass-stabilized nanocatalysts which might sharply reduce the catalytic treatment costs and broaden the scope of applications.

A new route for manufacturing poly(aminophosphonic)-functionalized poly(glycidyl methacrylate)-magnetic nanocomposite - Application to uranium sorption from ore leachate.

A high-energy ball milling of magnetite nanoparticles with amino-phosphonic functionalized poly(glycidyl methacrylate) polymer is used for manufacturing a highly efficient magnetic sorbent for U(VI) sorption from aqueous solutions. The Uranyl ions were adsorbed through the binding with amine and phosphonic groups as confirmed by Fourier Transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The maximum sorption capacity (up to 270 mg U g-1) occurred at pH = 3-4; Langmuir isotherm well describes the sorption process. Small-size particles allow achieving fast uptake (within ≈90 min of contact); and the kinetic profiles are modeled by the pseudo-second order rate equation. Uranium is successfully desorbed from loaded sorbent using 0.25 M NaHCO3 solution: Sorbent can be recycled with minimal decrease in sorption and desorption efficiency for at least 6 cycles. The sorbent is efficiently used for U(VI) recovery from the acidic leachates of U-bearing ores (after precipitation pre-treatment). Sorption capacity approaches 190 mg U g-1 despite the presence of high concentrations of Fe and Si: the sorbent has a marked preference for U(VI) (confirmed by distribution ratios and selectivity coefficients).

Efficacy and toxicity of plasmonic photothermal therapy (PPTT) using gold nanorods (GNRs) against mammary tumors in dogs and cats.

Plasmonic photothermal therapy (PPTT) was introduced as a promising treatment of cancer. This work was conducted to evaluate the cytotoxic effect of intratumoral (IT) injection of 75µg gold nanorods (GNRs)/kg of body weight followed by direct exposure to 2 w/cm2 near infra-red laser light for 10min on ablation of mammary tumor in 10 dogs and 6 cats. Complete blood count (CBC), liver and kidney function were checked before the start of treatment and one month after injection of GNRs. Results showed that 62.5% (10/16), 25% (4/16) and 12.5% (2/16) of treated animals showed complete remission, partial remission and no response, respectively. Tumor was relapsed in 4 cases of initially responding animals (25%). Overall survival rate was extended to 315.5±20.5days. GNRs have no toxic effect on blood profile, liver or kidney functions. In conclusion, GNRs can be safely used for treatment of mammary tumors in dogs and cats.

Phoenix dactylifera L. leaf extract phytosynthesized gold nanoparticles; controlled synthesis and catalytic activity.

A green synthesis route was reported to explore the reducing and capping potential of Phoenix dactylifera extract for the synthesis of gold nanoparticles. The processes of nucleation and growth of gold nanoparticles were followed by monitoring the absorption spectra during the reaction. The size and morphology of these nanoparticles was typically imaged using transmission electron microscopy (TEM). The particle size ranged between 32 and 45 nm and are spherical in shape. Fourier transform infrared (FTIR) analysis suggests that the synthesized gold nanoparticles might be stabilized through the interactions of hydroxyl and carbonyl groups in the carbohydrates, flavonoids, tannins and phenolic acids present in P. dactylifera. The as-synthesized Au colloids exhibited good catalytic activity for the degradation of 4-nitrophenol.

Tissue distribution and efficacy of gold nanorods coupled with laser induced photoplasmonic therapy in ehrlich carcinoma solid tumor model.

Gold nanorods (GNR) within tumor microregions are characterized by their ability to absorb near IR light and emit heat in what is called photoplasmonic effect. Yet, the efficacy of nanoparticles is limited due to intratumoral tissue distribution reasons. In addition, distribution of GNRs to normal tissue might result in non specific toxicity. In the current study, we are assessing the intratumoral and tissue distribution of PEGylated GNRs on the top of its antitumor characteristics when given intravenously or intratumoral to solid tumor bearing mice and coupled with laser photoplasmonic sessions. PEGylated GNRs with a longitudinal size of less than 100 nm were prepared with aspect ratio of 4.6 showing strong surface plasmon absorption at wavelength 800 nm. Pharmacokinetics of GNR after single I.V. administration (0.1 mg/kg) showed very short systemic circulating time (less than 3 h). On the other hand, tissue distribution of I.V. GNR (0.1 mg/kg) to normal animals showed preferential deposition in spleen tissue. Repeated administration of I.V. GNR resulted in preferential accumulation in both liver and spleen tissues. In addition, I.V. administration of GNR to Ehrlich carcinoma tumor bearing mice resulted in similar tissue distribution; tumor accumulation and anti-tumor effect compared to intratumoral administration. In conclusion, the concentration of GNR achieved within tumors microregions after I.V. administration was comparable to I.T. administration and sufficient to elicit tumoral growth arrest when coupled with laser-aided photoplasmonic treatment.

Malva parviflora extract assisted green synthesis of silver nanoparticles.

Five plant leaf extracts (Malva parviflora, Beta vulgaris subsp. Vulgaris, Anethum graveolens, Allium kurrat and Capsicum frutescens) were screened for their bioreduction behavior for synthesis of silver nanoparticles. M. parviflora (Malvaceae) was found to exhibit the best reducing and protecting action in terms of synthesis rate and monodispersity of the prepared silver nanoparticles. Our measurements indicate that biosynthesis of Ag nanoparticles by M. parviflora produces Ag nanoparticles with the diameters in the range of 19-25 nm. XRD studies reveal a high degree of crystallinity and monophasic Ag nanoparticles of face-centered cubic structure. FTIR analysis proved that particles are reduced and stabilized in solution by the capping agent that is likely to be proteins secreted by the biomass. The present process is an excellent candidate for the synthesis of silver nanoparticles that is simple, easy to perform, pollutant free and inexpensive.