No abstract

No abstract

No abstract

No abstract

No abstract

Recent toxicological studies on carbon nanomaterials, including fullerenes, have led to concerns about their safety. Functionalized fullerenes, such as polyhydroxy fullerenes (PHF, fullerols, or fullerenols), have attracted particular attention due to their water solubility and toxicity. Here, we report surprisingly beneficial and/or specific effects of PHF on model organisms representing four kingdoms, including the green algae Pseudokirchneriella subcapitata, the plant Arabidopsis thaliana, the fungus Aspergillus niger, and the invertebrate Ceriodaphnia dubia. The results showed that PHF had no acute or chronic negative effects on the freshwater organisms. Conversely, PHF could surprisingly increase the algal culture density over controls at higher concentrations (i.e., 72% increase by 1 and 5 mg/L of PHF) and extend the lifespan and stimulate the reproduction of Daphnia (e.g. about 38% by 20 mg/L of PHF). We also show that at certain PHF concentrations fungal growth can be enhanced and Arabidopsis thaliana seedlings exhibit longer hypocotyls, while other complex physiological processes remain unaffected. These findings may open new research fields in the potential applications of PHF, e.g., in biofuel production and aquaculture. These results will form the basis of further research into the mechanisms of growth stimulation and life extension by PHF.

The novel optical properties of polyhydroxy fullerenes (PHF)—which are water‐soluble, biodegradable and antioxidant—are applied for imaging and therapy of cancer. Tumors injected with PHF are imaged with photoacoustic tomography (PAT) and photothermally treated with near‐infrared (NIR) laser. Tumor size decreases up to 72% within two hours of treatment, with only a blister visible after 20 hours.

Abstract.A rapid, quantitative microbial assay, which is specific for heavy metal toxicity, has been developed. The assay (MetPLATE TM) is in a 96-well microtitration plate format and is suitable for determining toxicity characteristics such as median inhibitory concentrations. The sensitivity of MetPLATE TM to heavy metals [Cu, Zn, Cd, Pb, Hg, Cr(III)] was generally higher than Microtox and was of the same order as or better than Daphnia and fish bioassay. MetPLATE was insensitive to organic compounds at concentrations higher than those found in the environment. Six out of 10 industrial wastewaters or process waters surveyed were toxic. Heavy metal analysis of these waters confirmed the presence of heavy metals in the toxic samples. MetPLATE can be run concurrently with other assays for general toxicity to help determine the nature of chemicals causing toxicity.The deleterious effect of chemicals in the environment has traditionally been assessed with indicator organisms such as fish and invertebrates. Due to the large inventory of chemicals and the time-consuming nature of the traditional bioassays, microbioassays based on protozoa, microalgae, bacteria, and enzymes have become increasingly popular for the screening of environmental toxicants Dutka and Bitton, 1986). The trend in microbioassays is to package the assays in test kits, which facilitates application of toxicityscreening assays in the field or at smaller laboratories (Bitton and Koopman 1992).A limited number of test kits are presently available. The ECHA Biocide Monitor is a qualitative test based on inhibition of dehydrogenase activity and requires 18-24 h for completion (Dutka and Gorrie 1989). The Polytox kit includes a mixture of bacterial cultures, isolated from wastewater, which are used in respirometric tests (Elnabarawy et al. 1988). The Toxi-chromo Test is based on the inhibition of the biosynthesis of 13-galactosidase in Escherichia coli (Reinhartz et al. 1987). Both the Polytox and Toxi-chromo tests are quantitative tests, because they enable the determination of ECsos.Correspondence to: G. Bitton A common feature of currently available microbioassay kits is that they test for general toxicity, i.e., they respond to both heavy metal and organic toxicants. Apparently, hydrolases, particularly [3-galactosidase, are not sensitive to toxic organic compounds. In fact, researchers are still assaying for [3-galactosidase activity in the presence of sodium dodecyl sulfate, an organic chemical that is highly toxic to many of the test organisms used in toxicity testing protocols. [3-Galactosidase is also stable in pure acetone (Bitton, Kolar, and Koopman, unpublished data). This prompted investigation of the sensitivity of this enzyme to organic and inorganic toxicants. The results show that, indeed, [3-galactosidase is insensitive to all of the organic toxicants tested, while being sensitive to heavy metals (Dutton et al. 1988;Bitton et al. 1992aBitton et al. , 1992b.A qualitative assay that is specific for heavy metal toxicity and is not affect...