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.

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.

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.

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.

A study of the mechanism of in vitro cytotoxicity of metal oxide nanoparticles using catfish primary hepatocytes and human HepG2 cells.

Nanoparticles (NPs), including nanometal oxides, are being used in diverse applications such as medicine, clothing, cosmetics and food. In order to promote the safe development of nanotechnology, it is essential to assess the potential adverse health consequences associated with human exposure. The liver is a target site for NP toxicity, due to NP accumulation within it after ingestion, inhalation or absorption.

Choosing safe dispersing media for C60 fullerenes by using cytotoxicity tests on the bacterium Escherichia coli.

Assessment of C(60) nanotoxicity requires a variety of strategies for dispersing it into biological systems. Our objective was to determine organic solvent/surfactant combinations suitable for this purpose. We used Escherichia coli (ATCC# 25254) to determine the cytotoxicity of C(60) in solvents at concentrations up to 100 ppm.

Comparing the relative toxicity of malathion and malaoxon in blue catfish Ictalurus furcatus.

Malathion inhibits the critical body enzyme, acetylcholinesterase (AChE). This capability requires that malathion should first be converted to malaoxon to become an active anticholinesterase agent. Conversion can be caused by oxidation in mammals, insects, plants, and in sunlight.