Synthesis and design of Ag-Fe bimetallic nanoparticles as antimicrobial synergistic combination therapies against clinically relevant pathogens.

The inappropriate use of antibiotics and the inadequate control of infections have led to the emergence of drug-resistant strains. In recent years, metallo-pharmaceutics and metallic nanoparticles have been proposed as potential alternative antimicrobials due to their broad-spectrum antimicrobial properties. Moreover, recent findings have shown that combinations of transition metal compounds can exhibit synergistic antimicrobial properties. Therefore, the synthesis and design of bimetallic nanoparticles is a field worth exploring to harness the interactions between groups of metals and organic complex structures found in different microbial targets, towards the development of more efficient combinatorial antimicrobials composed of synergistic metals. In this study, we present a green synthesis of Ag-Fe bimetallic nanoparticles using an aqueous extract from the leaves of Gardenia jasminoides. The characterization of the nanoparticles demonstrated that the synthesis methodology produces homogenously distributed core-shell Ag-Fe structures with spherical shapes and average diameter sizes of 13 nm (± 6.3 nm). The Ag-Fe bimetallic nanoparticles showed magnetic and antimicrobial properties; the latter were evaluated against six different, clinically relevant multi-drug-resistant microbial strains. The Ag-Fe bimetallic nanoparticles exhibited an antimicrobial (bactericidal) synergistic effect between the two metals composing the bimetallic nanoparticles compared to the effects of the mono-metallic nanoparticles against yeast and both Gram-positive and Gram-negative multidrug-resistant bacteria. Our results provide insight towards the design of bimetallic nanoparticles, synthesized through green chemistry methodologies, to develop synergistic combinatorial antimicrobials with possible applications in both industrial processes and the treatment of infections caused by clinically relevant drug-resistant strains.

Therapeutic Applications of Cannabinoids in Cardiomyopathy and Heart Failure.

A large number of cannabinoids have been discovered that could play a role in mitigating cardiac affections. However, none of them has been as widely studied as cannabidiol (CBD), most likely because, individually, the others offer only partial effects or can activate potential harmful pathways. In this regard, CBD has proven to be of great value as a cardioprotective agent since it is a potent antioxidant and anti-inflammatory molecule. Thus, we conducted a review to condensate the currently available knowledge on CBD as a therapy for different experimental models of cardiomyopathies and heart failure to detect the molecular pathways involved in cardiac protection. CBD therapy can greatly limit the production of oxygen/nitrogen reactive species, thereby limiting cellular damage, protecting mitochondria, avoiding caspase activation, and regulating ionic homeostasis. Hence, it can affect myocardial contraction by restricting the activation of inflammatory pathways and cytokine secretion, lowering tissular infiltration by immune cells, and reducing the area of infarct and fibrosis formation. These effects are mediated by the activation or inhibition of different receptors and target molecules of the endocannabinoid system. In the final part of this review, we explore the current state of CBD in clinical trials as a treatment for cardiovascular diseases and provide evidence of its potential benefits in humans.

In vivo antimicrobial activity of silver nanoparticles produced via a green chemistry synthesis using Acacia rigidula as a reducing and capping agent.

INTRODUCTION: One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells. PURPOSE: In this study, we report a green one-pot synthesis method that uses Acacia rigidula extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo. MATERIALS AND METHODS: The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet-visible, and Fourier transform infrared. RESULTS: We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and a clinical multidrug-resistant strain of P. aeruginosa) and Gram-positive (Bacillus subtilis) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant P. aeruginosa clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were monitored in the murine infection model, and the results demonstrate that Ag-NPs can be used safely as therapeutic agents in animal models. CONCLUSION: Together, these results suggest the potential use of Ag-NPs, synthesized by green chemistry methods, as therapeutic agents against infections caused by resistant and nonresistant strains.