Fullerene Nanomaterials Research Articles

Fullerene nanomaterials potentiate hair growth

Hair loss is a common symptom resulting from a wide range of disease processes and can lead to stress in affected individuals. The purpose of this study was to examine the effect of fullerene nanomaterials on hair growth. We used shaved mice as well as SKH-1 “bald” mice to determine if fullerene-based compounds could affect hair growth and hair follicle numbers. In shaved mice, fullerenes increase the rate of hair growth as compared with mice receiving vehicle only. In SKH-1 hairless mice fullerene derivatives given topically or subdermally markedly increased hair growth. This was paralleled by a significant increase in the number of hair follicles in fullerene-treated mice as compared with those mice treated with vehicle only. The fullerenes also increased hair growth in human skin sections maintained in culture. These studies have wide-ranging implications for those conditions leading to hair loss, including alopecia, chemotherapy, and reactions to various chemicals.

HIGH YIELD PREPARATION OF FULLERENE NANOWHISKERS AND NANOTUBES BY THE SOLUTION ROUTE

The effect of ultraviolet, visible and near-infrared irradiation on the yield and morphology of single crystalline C 60 fullerene nanowhiskers (FNWs) and nanotubes (FNTs) was investigated in an effort to produce large-scale quantities of FNWs and FNTs. These fullerene nanomaterials were synthesized by the liquid–liquid interfacial precipitation method using pyridine and isopropyl alcohol (IPA) as solvents. The C 60–pyridine solution was illuminated using different wavelengths for 24 h at ambient pressure and temperature before addition of IPA. High yields (30–38 mg/L) were obtained upon irradiation using wavelengths in the ultraviolet region in accordance with the increased photoabsorption signal of solid C 60 and C 60 dissolved in pyridine acquired by a UV-VIS-NIR spectrophotometer. However, elevated yields (21–27 mg/L) were also obtained in the 600–800 nm regions, where C 60 absorption is particularly weak. Such an enhanced yield of FNTs and FNWs is probably related to the reported rise in transient absorption of the triplet excited state of C 60 in the 740 nm region formed by the decay of the photoexcited singlet C 60 through intersystem crossing. The formation of photopolymerized fullerene nanofibers was also observed by Raman spectroscopy, it is attributed to ultraviolet and visible light irradiation. SEM and TEM observations suggest that preparation of FNWs and FNTs by irradiation using different wavelengths of light does not produce apparent morphological transformations on the surface of these fullerene materials.

Effects of C60fullerene nanoparticles on soil bacteria and protozoans

Nanotechnology should produce numerous new materials in the coming years. Because of the novel design of nanomaterials with new physicochemical characteristics, their potential adverse impact on the environment and human health must be addressed. In the present study, agglomerates of pristine C60 fullerenes (50 nm to microm-size) were applied to soil at 0, 5, 25, and 50 mg/kg dry soil to assess their effect on the soil microbiota by measuring total respiration; biomass, number, and diversity of bacteria; and total number and diversity of protozoans during 14 d. Respiration and microbial biomass were unaffected by the fullerenes at any time, whereas the number of fast-growing bacteria was decreased by three- to fourfold just after incorporation of the nanomaterial. Protozoans seemed not to be very sensitive to C60, because their number decreased only slightly in the beginning of the experiment. With polymerase chain reaction and denaturing gradient gel electrophoresis analysis of eubacteria and kinetoplastids from the soil, however, a difference between the fullerene treatments and nonamended controls was demonstrated. The fullerenes did not induce more than 20 to 30% of relative dissimilarity (with both bacteria and protozoans) between treatments, but this effect was persistent throughout the experiment. It therefore is recommended that fullerene nanomaterial not be spread deliberately in the environment and that their ecotoxicology be further clarified.

Pristine (C60) and Hydroxylated [C60(OH)24] Fullerene Phototoxicity towards HaCaT Keratinocytes: Type I vs Type II Mechanisms

The increasing use of fullerene nanomaterials has prompted widespread concern over their biological effects. Herein, we have studied the phototoxicity of gamma-cyclodextrin bicapped pristine C 60 [(gamma-CyD) 2/C 60] and its water-soluble derivative C 60(OH) 24 toward human keratinocytes. Our results demonstrated that irradiation of (gamma-CyD) 2/C 60 or C 60(OH) 24 in D 2O generated singlet oxygen with quantum yields of 0.76 and 0.08, respectively. Irradiation (>400 nm) of C 60(OH) 24 generated superoxide as detected by the EPR spin trapping technique; superoxide generation was enhanced by addition of the electron donor nicotinamide adenine dinucleotide (reduced) (NADH). During the irradiation of (gamma-CyD) 2/C 60, superoxide was generated only in the presence of NADH. Cell viability measurements demonstrated that (gamma-CyD) 2/C 60 was about 60 times more phototoxic to human keratinocytes than C 60(OH) 24. UVA irradiation of human keratinocytes in the presence of (gamma-CyD) 2/C 60 resulted in a significant rise in intracellular protein-derived peroxides, suggesting a type II mechanism for phototoxicity. UVA irradiation of human keratinocytes in the presence of C 60(OH) 24 produced diffuse intracellular fluorescence when the hydrogen peroxide probe Peroxyfluor-1 was present, suggesting a type I mechanism. Our results clearly show that the phototoxicity induced by (gamma-CyD) 2/C 60 is mainly mediated by singlet oxygen with a minor contribution from superoxide, while C 60(OH) 24 phototoxicity is mainly due to superoxide.

Reducing hazardous material and environmental impact through recycling of scandium nanomaterial waste

The emerging use of scandium and the environmental impact from scandium-containing waste is a rising environmental and health concern. With the development of new materials in the last decade, toxicological studies on those new materials have also been increasing. An example of a process which employs scandium is the generation of metallic nitride fullerene nanomaterials. This process typically generates 99+% scandium waste, as only small amounts of scandium are actually incorporated into the target fullerene molecules. We demonstrate a safe method to recover the scandium content in the waste, reuse the recovered material and successfully demonstrate a comparable product distribution without detectable health and environmental concerns.

Importance of oxidative stress in the pathogenesis and treatment of asthma

The purpose of the current review is to summarize recent evidence demonstrating the important role of oxidative stress in asthma pathogenesis. The therapeutic implications of these findings will be presented. Mechanistically, the effect of oxidative stress on dendritic cells has been demonstrated to have a potent effect on Th1/Th2 skewing of the immune response. Investigations of gene-environment interactions have identified genetic polymorphisms associated with individual susceptibility to pollutant-induced respiratory oxidative stress. The effects of current asthma therapy on oxidative stress are currently unclear, but previous trials using conventional antioxidant therapy in asthma have been largely ineffective. Recent investigations have identified two promising broad-based therapeutic approaches: Nrf2 pathway activation and the use of thiol precursors. Preliminary data suggest that fullerene nanomaterials and dietary interventions may also have potential benefits in asthma. Our current understanding of the role of oxidative stress in asthma suggests that antioxidant therapy may be important in optimizing asthma treatment and prevention. The future success of antioxidant asthma therapy will require strategies with broad effects on airway redox equilibrium and the selection of appropriate target populations.

Magnetite Nanoparticles in Fullerite C60Powder

Data are presented on the resonance and magnetic properties of Fe–fullerene nanomaterials prepared by heating a mixture of C60 fullerene and iron(III) acetylacetonate. The starting-mixture composition is shown to have a significant effect on the particle size and properties of the resulting magnetite and the magnetic properties of the material. The influence of chemical treatment on the properties of the material is analyzed.

Effects of catalytic metals for synthesis of BN fullerene nanomaterials

Boron nitride (BN) fullerene nanomaterials were synthesized by an arc-melting method from Al/B, TiB 2, VB 2, Ga/B, YB 6, YB 6/Ni, NbB 2 powder in N 2/Ar mixture gas, and various structures were confirmed by high-resolution electron microscopy. From comparing of formation enthalpy with nitrogen and boron, tendency of catalysis metal for BN nanotube was characterized, which is a useful guideline for synthesis of BN fullerene nanomaterials.