Green synthesized titanium dioxide nanoparticles and their future applications in biomedicine, agriculture and industry

In the green synthesis of titanium dioxide nanoparticles (TiO2 NPs) chemical reagents are replaced with biological extracts. Conventional methods used in the manufacture of TiO2 NPs raise environmental issues as they use harmful chemicals and spend a high amount of energy. At a laboratory scale, biologically synthesized titanium dioxide nanoparticles (bio-TiO2 NPs) proved to be a suitable alternative to the chemically synthesized ones. The biological activity of NPs is mainly determined by their shape, size and crystalline structure. However, these characteristics are hardly controlled when natural sources of reagents are used and so bio-TiO2 NPs did not reach an advanced technology readiness level. In this paper, we reviewed the majority of the available studies referring to bio-TiO2 NPs. Our aim is to briefly present the efficiency of biochemicals from different living organisms in producing TiO2 nano-scale particles as well as the benefits bio-TiO2 NPs would bring to the biomedical, agricultural and industrial sectors. Finally, based on the available data we discuss the sustainability of bio-TiO2 NPs referring to their possible environmental, economic and societal impacts.

Microalgal Cell Biofactory—Therapeutic, Nutraceutical and Functional Food Applications

Microalgae are multifaceted photosynthetic microorganisms with emerging business potential. They are present ubiquitously in terrestrial and aquatic environments with rich species diversity and are capable of producing significant biomass. Traditionally, microalgal biomass is being used as food and feed in many countries around the globe. The production of microalgal-based bioactive compounds at an industrial scale through biotechnological interventions is gaining interest more recently. The present review provides a detailed overview of the key algal metabolites, which plays a crucial role in nutraceutical, functional foods, and animal/aquaculture feed industries. Bioactive compounds of microalgae known to exhibit antioxidant, antimicrobial, antitumor, and immunomodulatory effects were comprehensively reviewed. The potential microalgal species and biological extracts against human pathogens were also discussed. Further, current technologies involved in upstream and downstream bioprocessing including cultivation, harvesting, and cell disruption were documented. Establishing microalgae as an alternative supplement would complement the sustainable and environmental requirements in the framework of human health and well-being.

Optimization of a fluorogenic assay to determine caspase 3/7 activity in meat extracts

Usefulness of general-purpose fluorogenic assay kits to determine caspase 3/7 activity of biological extracts is highly compromised in meat-based samples due to their scarce enzyme concentration. In the present work, a straightforward protocol is presented with two main purposes: 1) to enhance sensitivity of the fluorogenic approach addressing caspase 3/7 activity in tissues showing scarce enzyme concentration such as skeletal muscle, and 2) to reduce/economize the volume of employed reagents. The enzyme extraction procedure, peptide substrate, dithiothreitol concentration and detection settings were appropriately optimized for use in microtiter-plate fluorometers. As a result, low to high enzyme activity extracts (from 10,000 to 260,000 relative fluorescence units) can be measured under developed sampling and experimental conditions. The fact that enzyme reactions took place in 96-microtiter well plates reduces the consumption of chemical compounds when analysing a high number of samples, thus contributing to environment sustainability.

Effect of Ascophyllum nodosum extracts on the growth, yield and antioxidant capacity of Haematococcus pluvialis carotenoids

Recent research has shown that the use of biological extracts, which contain a wide variety of nutrients and phytohormones are potentially useful in the production of plants of agricultural importance. Seaweed extracts are particularly rich in minerals and micronutrients necessary for the growth of microalgae. The effect of three commercial extracts of Ascophyllum nodosum as plant growth inducers (Stimplex®, Acadian Soils® and Liquid Seaweed Concentrate®), provided by Acadian Sea Plants Ltd., were evaluated in relation to the growth and production of biomass and carotenoids in Haematococcus pluvialis. The results were evaluated by one-way ANOVA and post-hoc analysis utilizing Tukey's test with a significance level of 95% (α= 0.05). The reference medium used was the Bold basal medium, to which 250 ppm of each extract was added. The Stimplex® extract had an increase of 22.79% in cell density and 17% in dry matter, higher than the control culture. The content of carotenoids and antioxidant capacity, respectively, with Stimplex® was 30.05% and 141.76% higher than the control culture.

The Application of Biotechnology in the Synthesis of Metal/Metal Oxides Nanoparticles

This paper is aimed at reviewing the application of biological extracts from plants, fungi and bacteria in the synthesis of metal/metal oxide nanoparticles with reference to Ag and TiO2 nanoparticles as a case study. The procedures for the extraction of the biological extracts as well as the chemical instrumentation analysis of the extracts and metal/metal oxide nanoparticles were explained in this review. It was reported that standard chemical test confirms the presence of tannins, alkanoids, flavonoids and terpenoids in various plant extracts, while FTIR characterization of various biological extracts confirms the presence of organic compounds as a capping and reducing agents in the biosynthetic process for the preparation of the nanoparticles. The use of other instrumental techniques such as FESEM, XRD, SEM, EDX, TEM and UV-Visible spectroscopy in the characterization of biosynthesized metal/metal oxide nanoparticles were also explained in this review.

MARINE BIO-NANOTECHNOLOGY SILVER (AgNPs) OF MANGROVE EXTRACT AND ITS APLICATION : A REVIEW

The synthesis of nanoparticles (NP) using marine plants has been well developed. In recent years, few reports of NP synthesis use mangroves, which are used as bio plants for synthesis. In addition, mangroves are a renewable, sustainable and economical source compared to other marine organisms, so they can be explored effectively in the synthesis of green NPs (Green Synthesis). Therefore, this study reports on the biosynthesis of NP, especially silver nanoparticles (AgNPs) using mangrove extracts. NPs synthesized by this method are primarily spherical with promising anti-microbial potential. The biosynthesis of silver nanoparticles can be triggered by several compounds such as carbonyl, terpenoid, phenolic, tannin, flavonone, amine, amide, protein, pigment, alkaloid and other reducing agents in biological extracts capable of as reducing agents and capping agents. Marine bio-nanotechnology has great promise in nanomedicines, groceries, pharmaceuticals and industrial fabrics for the future.

Quantitative profiling of carbonyl metabolites directly in crude biological extracts using chemoselective tagging and nanoESI-FTMS

The investigators report a dramatically improved chemoselective analysis for carbonyls in crude biological extracts by turning to a catalyst and freezing conditions for derivatization.