Effect of Size and Crystalline Phase of TiO₂ Nanoparticles on Photocatalytic Inactivation of .

We studied the size dependent toxicity of TiO₂ nanoparticles (TiO₂ NPs; 5-50 nm) of the anatase and rutile crystalline phases (including the mixture of anatase and rutile) against the model organism . All the TiO₂ NPs were characterized and their photocatalytic inactivation of was studied under the solar simulated light irradiation and dark conditions. In addition, the mechanism of toxicity was studied by measurement of reactive oxygen species (ROS), an indicator of oxidative stress.

The current application of nanotechnology in food and agriculture.

The rapid development of nanotechnology has been facilitating the transformations of traditional food and agriculture sectors, particularly the invention of smart and active packaging, nanosensors, nanopesticides and nanofertilizers. Numerous novel nanomaterials have been developed for improving food quality and safety, crop growth, and monitoring environmental conditions. In this review the most recent trends in nanotechnology are discussed and the most challenging tasks and promising opportunities in the food and agriculture sectors from selected recent studies are addressed.

Structure characterization of low molecular weight sulfate Ulva polysaccharide and the effect of its derivative on iron deficiency anemia.

Sulfate Ulva polysaccharide with low molecular weight was prepared by enzymatic method and name SUE. The structural characterization of SUE and the effect of its derivative SUE-iron (III) on iron deficiency anemia were studied. Results showed SUE with molecular weight of 178 kDa were consisted of 57.

Directional preparation of anticoagulant-active sulfated polysaccharides from Enteromorpha prolifera using artificial neural networks.

The sulfated polysaccharides from Enteromorpha prolifera (PE) are a potential source of anticoagulant agents. In this study, the PE was degraded by specific degradase and five hydrolysis products with different molecular weights were prepared. The product of 206 kDa is a kind of high rhamnose-containing polysaccharide with sulfate ester (34.

Toxicity of engineered nanomaterials mediated by nano-bio-eco interactions.

Engineered nanomaterials may adversely impact human health and environmental safety by nano-bio-eco interactions not fully understood. Their interaction with biotic and abiotic environments are varied and complicated, ranging from individual species to entire ecosystems. Their behavior, transport, fate, and toxicological profiles in these interactions, addressed in a pioneering study, are subsequently seldom reported.

Nanostructures: Current uses and future applications in food science.

Recent developments in nanoscience and nanotechnology intend novel and innovative applications in the food sector, which is rather recent compared with their use in biomedical and pharmaceutical applications. Nanostructured materials are having applications in various sectors of the food science comprising nanosensors, new packaging materials, and encapsulated food components. Nanostructured systems in food include polymeric nanoparticles, liposomes, nanoemulsions, and microemulsions.

Nanotechnology in food science: Functionality, applicability, and safety assessment.

Rapid development of nanotechnology is expected to transform many areas of food science and food industry with increasing investment and market share. In this article, current applications of nanotechnology in food systems are briefly reviewed. Functionality and applicability of food-related nanotechnology are highlighted in order to provide a comprehensive view on the development and safety assessment of nanotechnology in the food industry.

Characterization of high yield exopolysaccharide produced by Phyllobacterium sp. 921F exhibiting moisture preserving properties.

A new strain bacteria was isolated and named as Phyllobacterium sp. 921F, due to its high production capacity of exopolysaccharide (EPS). Characterization of physico-chemical properties of the EPS and optimization for high production were conducted to aim at industrial applications.

Assessing the effect of different natural dissolved organic matters on the cytotoxicity of titanium dioxide nanoparticles with bacteria.

Titanium dioxide nanoparticles (TiO NPs) are among the most widely manufactured nanomaterials on a global scale. However, prudent and vigilant surveillance, incumbent upon the scientific community with the advent of new technologies, has revealed potentially undesirable effects of TiO NPs on biological systems and the natural environment during their application and discharge. Such effects are likely best evaluated by first assessing the fate of the TiO NPs in natural environments.

Optimization study on the hydrogen peroxide pretreatment and production of bioethanol from seaweed Ulva prolifera biomass.

The seaweed Ulva prolifera, distributed in inter-tidal zones worldwide, contains a large percentage of cellulosic materials. The technical feasibility of using U. prolifera residue (UPR) obtained after extraction of polysaccharides as a renewable energy resource was investigated.

Assessing the effects of surface-bound humic acid on the phototoxicity of anatase and rutile TiO₂ nanoparticles in vitro.

In this study, the cytotoxicity of two different crystal phases of TiO2 nanoparticles, with surface modification by humic acid (HA), to Escherichia coli, was assessed. The physicochemical properties of TiO2 nanoparticles were thoroughly characterized. Three different initial concentrations, namely 50, 100, and 200 ppm, of HA were used for synthesis of HA coated TiO2 nanoparticles (denoted as A/RHA50, A/RHA100, and A/RHA200, respectively).

Purification and characterization of polysaccharides degradases produced by Alteromonas sp. A321.

Two different degradases from Alteromonas sp. A321 for polysaccharides from Enteromorpha prolifera (DPE-L and DPE-P) were purified to homogeneity. The molecular weights of purified DPE-L and DPE-P were 75.

Rheological properties, gelling behavior and texture characteristics of polysaccharide from Enteromorpha prolifera.

Polysaccharide from Enteromorpha prolifera (PE) which is the most common green algae is gradually becoming an attractive candidate with novel functions by virtue of its unique chemical and physicochemical properties. The infrared spectrum (FT-IR) of PE confirmed that it is a distinctive, sulfated heteropolysaccharide. Dynamic rheology was systematically conducted to investigate the effect of concentration, temperature, pH, and electrolytes on PE.

Metal Oxide Nanomaterials in Nanomedicine: Applications in Photodynamic Therapy and Potential Toxicity.

Metal oxide nanomaterials have exhibited excellent performance as nanomedicines in photodynamic therapy (PDT) for cancer and infection treatment. Their unique and tunable physicochemical properties advance them as promising alternatives in drug delivery, early diagnosis, imaging, and treatment against various tumors and infectious diseases. Moreover, the implementation of nanophototherapy in deep tissue sites is enhanced by advancements in photosensitization technology.

Trends in infant mortality in United States: a brief study of the Southeastern states from 2005-2009.

While overall infant mortality rates have declined over the past several decades, the Southeastern states have remained the leading states in high infant death in the United States. In this study, we studied the differences in infant mortality in the southeastern United States from 2005 through 2009 according to mother's characteristics (age of mother, marital status, maternal race, maternal education), birth characteristics (month when maternal prenatal care began, birth weight), and infant's characteristics (age of infant at death). This paper illustrates the significance level of each characteristic of mothers and infants, as well as socioeconomic factors that contribute to significant infant mortality that impacts subgroups within the US population.

An in vivo study on the photo-enhanced toxicities of S-doped TiO2 nanoparticles to zebrafish embryos (Danio rerio) in terms of malformation, mortality, rheotaxis dysfunction, and DNA damage.

The role of light on the acute toxicities of S-doped and Sigma TiO2 nanoparticles in zebrafish was studied. Metrics included mortality for both, and rheotaxis dysfunction and DNA damage for S-doped only. It was found that the acute toxicity of S-TiO2 nanoparticles was enhanced by simulated sunlight (SSL) irradiation (96-h LC50 of 116.

Using a holistic approach to assess the impact of engineered nanomaterials inducing toxicity in aquatic systems.

In this report, we critically reviewed selected intrinsic physicochemical properties of engineered nanomaterials (ENMs) and their role in the interaction of the ENMs with the immediate surroundings in representative aquatic environments. The behavior of ENMs with respect to dynamic microenvironments at the nano-bio-eco interface level, and the resulting impact on their toxicity, fate, and exposure potential are elaborated. Based on this literature review, we conclude that a holistic approach is urgently needed to fulfill our knowledge gap regarding the safety of discharged ENMs.

Mechanisms of nanotoxicity: generation of reactive oxygen species.

Nanotechnology is a rapidly developing field in the 21(st) century, and the commercial use of nanomaterials for novel applications is increasing exponentially. To date, the scientific basis for the cytotoxicity and genotoxicity of most manufactured nanomaterials are not understood. The mechanisms underlying the toxicity of nanomaterials have recently been studied intensively.

Synergistic combination of marine oligosaccharides and azithromycin against Pseudomonas aeruginosa.

In this paper we describe how utilization of low molecular weight alginate-derived oligosaccharide (ADO) and chito-oligosaccharide (COS) in conjunction with antibiotics, could more effectively inhibit the growth of wild-type and resistant Pseudomonas aeruginosa. Inhibition is effected by modulating the bacteria's quorum sensing (QS) system, thus regulating biofilm formation and reducing resistance to antibiotic treatment. This can be demonstrated by using conventional MIC screening.

Effect of humic acids and sunlight on the cytotoxicity of engineered zinc oxide and titanium dioxide nanoparticles to a river bacterial assemblage.

The effect of a terrestrial humic acid (HA) and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles (ZnONPs) and titanium dioxide nanoparticles (TiO2NPs) to natural aquatic bacterial assemblages was measured with spread plate counting. The effect of HA (10 and 40 ppm) on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight (light irradiation (LI)). The experiment was of full factorial, completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software.

Using experimental data of Escherichia coli to develop a QSAR model for predicting the photo-induced cytotoxicity of metal oxide nanoparticles.

A quantitative structure-activity relationship (QSAR) study of seventeen metal oxide nanoparticles (MNPs), in regard to their photo-induced toxicity to bacteria Escherichia coli, was developed by using quantum chemical methods. A simple and statistically significant QSAR model (F=33.83, R(2)=0.

Determination of the mechanism of photoinduced toxicity of selected metal oxide nanoparticles (ZnO, CuO, Co3O4 and TiO2) to E. coli bacteria.

Cytotoxicity of selected metal oxide nanoparticles (MNPs) (ZnO, CuO, Co3O4 and TiO2) was investigated in Escherichia coli both under light and dark conditions. Cytotoxicity experiments were conducted with spread plate counting and the LC50 values were calculated. We determined the mechanism of toxicity via measurements of oxidative stress, reduced glutathione, lipid peroxidation, and metal ions.

Effects of light energy and reducing agents on C60-mediated photosensitizing reactions.

Many biomolecules contain photoactive reducing agents, such as reduced nicotinamide adenine dinucleotide (NADH) and 6-thioguanine (6-TG) incorporated into DNA through drug metabolism. These reducing agents may produce reactive oxygen species under UVA irradiation or act as electron donors in various media. The interactions of C60 fullerenes with biological reductants and light energy, especially via the Type-I electron-transfer mechanism, are not fully understood although these factors are often involved in toxicity assessments.

The optimization of saccharification of desulfurated red seaweed-derived polysaccharides and analysis of their composition.

Currently processes of ethanol production from desulfurated red seaweed derived polysaccharides (De-RSDP) are well established. However, the optimization of the enzymatic saccharification process has not been reported. In this study, De-RSDP from Kappaphycus alvarezii was subjected to saccharification by different enzymes, including pectinase, cellobiase, cellulase, and hemicellulase.

Production of enzymes by Alteromonas sp. A321 to degrade polysaccharides from Enteromorpha prolifera.

Polysaccharides from Enteromorpha prolifera (PE) are becoming increasingly popular due to its bioactivity and abundant source. Screening novel microorganisms which could secrete enzymes to degrade PE efficiently for oligosaccharides production is a promising solution to improve its application. In this study, a marine bacterium that can produce enzymes to degrade PE specifically was selected.