Green Synthesis of Metallic Nanoparticles, Phytochemical Compounds and Antioxidant Activity Using Two Types of Algae Plants

Scientific studies have demonstrated that the vegetable material extracts act as potential precursors for the synthesis of nanomaterial using eco-friendly ways. Because the plant extracts contain various secondary metabolites, they act as reducing and stabilizing agents for the bioreduction reaction for synthesis of novel metallic nanoparticles. Herein, we describe the characteristics of different algae types, from different locations (Belgium and South Correa). Algae have important components, like chlorophyll and other plant pigments, omega-3 fatty acids and essential elements. Also, it has been demonstrated that algae provide a rich source of natural bioactive compounds with antibacterial and antioxidant properties. Another important aspect is the fact that algae represent a good wastewater treatment. In addition to the economic aspect, algae biomass is a source of biodiesel and offers an efficient way for nutrient consumption and provides aerobic bacteria with oxygen through photosynthesis. It is a low-cost technique for the removal of phosphorus, nitrogen and pathogens. We first characterized and compared quantitatively (polyphenols, flavonoids) and qualitatively (carbohydrates, alkaloids) the properties of two algae types extracts (green algae - Enteromorpha spp. and brown ones - Hizikia fusiforme). We then obtained and characterized the gold nanoparticles, formed using HAuCl4 (10-3 M) and algae sample extracts. The algae extracts, the green method for obtaining metallic nanoparticles (AuNP) and the nanoparticles investigated by UV-Vis spectroscopy, optical microscopy and SEM technique are shown in this research

Antioxidant Activity and Phytochemical Compounds of Capsicum annuum L.

The benefits of Capsicum annuum L. are important for human health with its anti-inflammatory [...

Obtaining and Characterizing Composite Biomaterials of Animal Resources with Potential Applications in Regenerative Medicine

Raw materials, such as collagen and chitosan, obtained from by-products from the food industry (beef hides and crustacean exoskeletons), can be used to obtain collagen–chitosan composite biomaterials, with potential applications in regenerative medicine. Functionalization of these composite biomaterials is a possibility, thus, resulting in a molecule with potential applications in regenerative medicine, namely clotrimazole (a molecule with antibacterial, antifungal, and antitumor activity), at a mass ratio (collagen–chitosan–clotrimazole) of 1:1:0.1. This functionalized composite biomaterial has great potential for application in regenerative medicine, due to the following properties: (1) it is porous, and the pores formed are interconnected, due to the use of a mass ratio between collagen and chitosan of 1:1; (2) the size of the formed pores is between 500–50 μm; (3) between collagen and chitosan, hydrogen bonds are formed, which ensure the unity of composite biomaterial; (4) the functionalized bio-composite exhibits in vitro antimicrobial activity for Candida albicans, Staphylococcus aureus, and Staphylococcus aureus MRSA; for the latter microorganism, the antimicrobial activity is equivalent to that of the antibiotic Minocycline; (5) the proliferation tests performed on a standardized line of normal human cells with simple or composite materials obtained by lyophilization do not show cytotoxicity in the concentration range studied (10–500) μg/mL

Wood preservation with gold hydroxyapatite system

Abstract Over centuries, the external factors such as fire, low temperature, light or microbiological agents, act on the wood and induce some degradation processes, sometimes irreversible, identified by discoloration, fragility and unsightly appearance. Although there are numerous literature reports about different nanomaterials used for preservation and restoration of wood surfaces (calcium hydroxides, magnesium hydroxides, hydroxyapatite, or even organic resins as Paraloid B72), in this paper it is proposed a new system—gold hydroxyapatite (AuHAp), tested on the hazelnut wood samples (young and aged specimens), as a new solution for preservation of some wooden artifacts. This paper addresses a broad range of analytical methods: X-ray diffraction, UV–Vis spectrophotometry, Fourier transformed infrared spectroscopy, Raman spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, chromatic parameters and hardness test. Also, humidity sorption/desorption measurements are used for humidity sorption and desorption evaluation. The adsorption and desorption tests determined the hydroscopic sorption properties of the wood specimens by measuring the mass of the specimens in equilibrium with air at a specific temperature and RH. All the results concluded that after the application of the new system on the hazelnut wood surface, a well distributed and uniform layer consisting from AuHAp systems with a network aspect are observed, which covers the wood vessels and fibers, filling the voids and stopping the wood weathering process, more accentuated at aged wood than at the young species

<i>Ganoderma lucidum</i>-Mediated Green Synthesis of Silver Nanoparticles with Antimicrobial Activity

“Green chemistry” is a simple and easily reproductible method that provides nanoparticles characterized by better stability and good dispersion in an aqueous solution. Nanoparticles can be synthesized by algae, bacteria, fungi, and plant extracts. Ganoderma lucidum is a commonly used medicinal mushroom with distinctive biological properties, such as antibacterial, antifungal, antioxidant, anti-inflammatory, anticancer, etc. In this study, aqueous mycelial extracts of Ganoderma lucidum were used to reduce AgNO3 to form silver nanoparticles (AgNPs). The biosynthesized nanoparticles were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis. The maximum UV absorption was obtained at 420 nm, which represents the specific surface plasmon resonance band for biosynthesized silver nanoparticles. SEM images showed particles as predominantly spherical, while FTIR spectroscopic studies illustrated the presence of functional groups that can support the reducing of ion Ag+ to Ag(0). XRD peaks ratified the presence of AgNPs. The antimicrobial effectiveness of synthesized nanoparticles was tested against Gram-positive and Gram-negative bacterial and yeasts strains. The silver nanoparticles were effective against pathogens, inhibiting their proliferation, and thus reducing the risk to the environment and to public health