Probing the antioxidant activity of Δ9-tetrahydrocannabinol and cannabidiol in Cannabis sativa extracts.

Herein, we report the antioxidant activity of cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) in pure and mixed solutions at different ratios, as well as of six different Cannabis sativa extracts containing various proportions of CBD and THC by using spectrophotometric (reducing power assay, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), hypochlorous acid (HOCl) scavenging assays) and electrochemical methods (cyclic voltammetry and differential pulse voltammetry). The isolated cannabinoids, the different stoichiometric ratios of CBD and THC, and the natural extracts proved to have remarkable antioxidant properties in all the methods employed in this work. The antioxidant activity of CBD and THC was compared against that of the well-defined antioxidants such as ascorbic acid (AA), resveratrol (Resv) and (-)-epigallocatechin-3-gallate (EGCG). Clear evidence of the synergistic and antagonistic effects between CBD and THC regarding to their antioxidant activities was observed. Moreover, a good correlation was obtained between the optical and electrochemical methods, which proved that the reported experimental procedures can easily be adapted to determine the antioxidant activity of extracts from various Cannabis sativa species and related compounds.

Novel one step transformation method for Escherichia coli and Staphylococcus aureus using arginine-glucose functionalized hydroxyapatite nanoparticles.

Bacterial gene transformation is one of the important techniques in molecular biology which has significant applications in gene cloning technology. In this study, we have developed arginine-glucose functionalized hydroxyapatite nanoparticle (R-G-HAp NPs) mediated novel one step transformation method, effective for both Gram-positive and Gram-negative bacteria. R-G-HAp NPs served as carriers to deliver pDNA into Escherichia coli and Staphylococcus aureus at room temperature, without the need for preparation of competent cells. High transformation efficiency was achieved in Gram-positive, S. aureus (107 cfu/µg of pDNA) as well as Gram-negative, E. coli (109 cfu/µg of pDNA). This demonstrates the efficacy of R-G-HAp NPs as a nano-vehicle to achieve high plasmid transformation efficiency, even in Gram-positive bacteria which is usually a challenge, exhibiting their potential as promising synthetic non-viral vectors for efficient bacterial gene transformation.

A novel method for genetic transformation of C. albicans using modified-hydroxyapatite nanoparticles as a plasmid DNA vehicle.

In modern biological research, genetic transformation is an important molecular biology technique with extensive applications. In this work, we describe a new method for the delivery of plasmid DNA (pDNA) into a yeast species, Candida albicans. This method is based on the use of novel arginine-glucose-PEG functionalized hydroxyapatite nanoparticles (M-HAp NPs) as a vehicle which delivers pDNA into Candida albicans with a high transformation efficiency of 106 cfu µg-1 of pDNA, without the need for preparation of competent cells. A four-fold higher transformation efficiency as compared to that of the electroporation method was obtained. This new method could provide exciting opportunities for the advancement of the applications of yeasts in the field of biotechnology.

Self-Activated Fluorescent Hydroxyapatite Nanoparticles: A Promising Agent for Bioimaging and Biolabeling.

Bioimaging has drastically transformed the field of medicine, and made the process of diagnosis easy and fast. Visualization of complete organ to complex biological processes has now become possible. Among the various imaging processes, fluorescence imaging using nontoxic fluorescent nanomaterials is advantageous for several beneficial features including high sensitivity, minimal invasiveness, and safe detection limit. In this study, we have synthesized and characterized a new class of nontoxic, self-activated fluorescent hydroxyapatite nanoparticles (fHAps) with different aspect ratios (thin-rods, short-rods, rods) by changing the stabilizing agents (triethyl amine and acetyl acetone) and solvents (water and dimethyl sulfoxide). fHAps showed excellent fluorescence with a broad emission spectrum ranging from 350 to 750 nm and maximum at 502 nm. The presence of fluorescence was attributed to the electronic transition in the asymmetric structure of fHAps as confirmed by ESR spectroscopy and the absence of fluorescence in symmetric HAp NPs. In addition to exceptional fluorescence behavior, these NPs were found to be nontoxic in nature and could be easily internalized in both prokaryotic and eukaryotic systems. We propose that the fHAps provide a safe and a potential alternative to the current fluorescent materials in use for biolabeling and bioimaging applications.

Nanomaterial-Based Approaches for Prevention of Biofilm-Associated Infections on Medical Devices and Implants.

Biofilm formation is a major problem in medical device-related infections leading to failure of implant-based therapies. Though various conventional approaches to counter biofilm formation like physical and/or mechanical removal, chemical removal, and the use of antimicrobials exist, they fail due to increased resistance of biofilms. This review discusses various nanomaterial-based approaches such as the use of metallic and metal oxide nanoparticles- and polymer-based nanocomposites, which are currently being developed for prevention and treatment of biofilms. Nanoparticles of transition metals and their oxides are toxic to microorganisms and exhibit their toxicity through the generation of reactive oxygen species at concentrations that are non-toxic to eukaryotic cells. Other approaches include the entrapment of bioactive agents in polymer/ceramic nanoparticles, for enhanced anti-biofilm activity due to the synergistic effect between them. These nanomaterial-based approaches could play an important role in control and eradication of biofilm related infections and complications associated with medical devices and implants.