Plasmon-Modulated Excitation-Dependent Fluorescence and Antimicrobial Activities of Silver and Gold Nanoparticles Prepared with Eugenia unifloraL. extracts

Green synthesis using plant extract is a sustainable method to obtain silver and gold nanoparticles (Ag and AuNPs) and was employed in this work. The Eugenia uniflora L. fruits and leaves extracts were used in nanoparticles synthesis. The photoreduction process with a xenon lamp and pH control improved optical properties and nanoparticles stability. The UV-vis, TEM, FTIR, and Zeta potential of the prepared solutions were obtained. The fluorescence spectra of Ag and AuNPs were investigated at different excitation wavelengths, which showed two kinds of fluorescence peaks. The shorter wavelength peaks red-shift with the increasing excitation wavelength, which results from the electron interband transitions, and the longer fixed wavelength peaks due to the local field enhancement. Finally, the antimicrobial tests were performed with Gram-negative and Gram-positive bacteria and Candida albicans. The best results were obtained with EuAgNPs prepared with fruits extract, photoreduction, and pH 7.0 (with a mean of 95.12% ± 10.29% of inhibition).

Assessing the Role of Modern Excipients for Delivery of Gold Nanoparticles

Using the drug delivery approach, we explain the role lipids and polymers perform in the delivery of gold nanoparticles. They were tested alongside drug and polymer compatibility using pharmacodynamics and pharmacokinetics. The collected data demonstrate the production of gold nanoparticles' stability and strong therapeutic effects. We illustrate some of the intriguing categories of targeting systems for the delivery of Au G Nanoparticles that are under development. Polymers containing reactive functional groups to combine targeting binding sites, cell receptors, or drugs are also coated with nanoparticles engineered for biomedical applications. The present review focuses on utilization of modern excipients, lipids, polymers in formulation of delivery systems that can efficiently delivery the gold nanoparticles. Gold nanoparticles have outranged in their use for treating wide health diseases with limited side effects. The next generation medical deliverables are majorly focused on gold nanoparticles. Keywords: Gold nanoparticles, Lipids, Polymers, Delivery systems, Excipients, Diseases.

A Study of the Effects of pH and Surfactant Addition on Gold Nanoparticle Aggregation

Gold nanoparticles (AuNPs) can provide a simple, easy-to-use, inexpensive, at hand point-of-care (POC) fast to diagnose; however, AuNPs have the predisposition to form aggregations. Since the nanoparticles stability is an important issue, this article is aiming to study the long-term stability associated with the development of an immunosensor for clinical diagnosis. Here, we assessed two previous methods commonly described in the literature to prevent the formation of aggregate by studying pH and Tween® 20 (polysorbates) addition as surfactant. AuNPs were characterized through ultraviolet-visible (UV-Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM) and through analysis in the ImageJ software. We found that the Tween® 20 provided more than stable condition in aqueous solution in comparison to pH dependence. The fabricated AuNPs were further used to detect dengue virus and demonstrating that its use at pH 7.2 did not maintain reproducibility in the detection of dengue virus after one year. Unlike, the Tween® 20 modified AuNPs that detected dengue virus soon after the synthesis and over the course of one year demonstrating the high sensitivity of immunosensor. Finally, our result showed excellent dispersity throughout the year when using Tween® 20 to avoid aggregation.

Ferulic Acid-NLC with Lavandula Essential Oil: A Possible Strategy for Wound-Healing?

Nowadays, an increasing interest in combinatorial drug delivery systems is emerging, highlighting the possibility of exploiting essential oils (EO) for topical applications. This work aimed at developing nanostructured lipid carriers (NLC) for the combined delivery of ferulic acid and Lavandula EO, whose beneficial effects in wound-healing processes have been widely reported. Homogeneous (polydispersity index, PDI < 0.2) nanoparticles with a small size (<150 nm) and a high encapsulation efficiency (>85%) were obtained. The co-presence of ferulic acid and Lavandula EO, as compared to synthetic isopropyl myristate-based NLC, increased nanoparticles’ stability, due to higher ordering chains, as confirmed by morphological and physicochemical studies. An enhanced cytocompatibility was observed when combining ferulic acid and Lavandula EO, as confirmed by in vitro studies on fibroblasts. Furthermore, the combined delivery of ferulic acid and Lavandula EO significantly promoted cell migration with higher effectiveness in respect to the free drug solution and the carrier without the EO. Taken all together, our results suggest a potential combined effect of the antioxidant ferulic acid and Lavandula EO co-delivered in lipid nanoparticles in promoting cell proliferation and migration, representing a promising strategy in the treatment of wounds.