Antonella Pagnoni

TiO2 in Commercial Sunscreen Lotion: Flow Field-Flow Fractionation and ICP-AES Together for Size Analysis

A new method for determining the size of titanium dioxide particles is proposed and assayed in a commercial sunscreen product. Today many sun protection cosmetics incorporate physical UV filters as active ingredients, and there are no official methods for determining these compounds in sunscreen cosmetics. Here flow field-flow fractionation (FlFFF) has been tested, first to sort two different types of TiO2 nano- and microstandard materials (AeroxideTiO2 Degussa P-25 and TiO2 rutile 0.1-0.2-microm size) and then to fractionate TiO2 particles, extracted from a commercial sunscreen lotion. All the TiO2 FlFFF separations were detected by UV but during elution fractions were collected and their Ti content measured by inductively coupled plasma-atomic emission spectrometer (ICP-AES); the Ti concentration profiles obtained by ICP-AES were well correlated with the UV signals. The TiO2 particle mass-size distribution were calculated from the UV profiles. This methodology is relatively simple and rapid, and the sample treatment is as a whole easy and low cost.

TiO2 nano- and micro-particles in commercial foundation creams: Field Flow-Fractionation techniques together with ICP-AES and SQW Voltammetry for their characterization

A procedure to determine the presence of nano- or micro- TiO2 particles in commercial cosmetic formulations, which may have a daily use, is proposed. Two identification techniques the Square Wave Voltammetry (SWV) and ICP-AES were employed to determine the amount of TiO2 in six foundation creams sold in Italy and the USA. A new SWV method, based on an acidic microwave-assisted digestion of the sample, has been set up and the results were compared and critically commented with those obtained by the established ICP-AES method. The analytical procedure was verified by analyzing the P-25 Degussa sample. The sizes of the particles contained in the foundations were investigated through Sedimentation (SdFFF) and Flow Field-Flow Fractionation (FlFFF) by analyzing aqueous slurries obtained from the foundation through a solvent extraction procedure. The FFF techniques synergically coupled with the ICP-AES made it possible to assess the sizes of the TiO2 particles. The content of the extracted slurries was also checked by TEM observation.

Responses of Trapa natans L. floating laminae to high concentrations of manganese

Summary.The present study focuses on the responses of floating laminae of the Mn-tolerant hydrophyte Trapa natans L. to 1 mM Mn and their ability to accumulate the metal. Studies were carried out first on young floating laminae belonging to the second verticil of 30-day-old plants which originated from fruits that had been maintained in a 1 mM Mn-treated environment and again on the young floating laminae after 10 days of further treatment with 1 mM Mn. Mn storing was observed from the first days after germination, but only 10-day-treated laminae showed the capability to hyperaccumulate the element inside specialised cells (>20000 μg/g [dry weight]). Electron microscopy and the Folin–Ciocalteu reaction for phenolics revealed deposits of chelated material inside vacuoles of the first palisade layer and of idioblasts in the spongy tissue. X-ray microanalysis indicated that the deposits were Mn chelated with phenolic compounds. Numerous trichomes were observed at the lower epidermis of 10-day-treated laminae. They were rich in phenolics and characterised by Mn concretions at their base. As they are associated with a high concentration of the metal in culture water and sediments, trichomes may constitute a morphological differentiation for the secretion of Mn-chelating molecules into the culture water, as a probable “avoidance” mechanism. Finally, monitoring of the photosynthetic apparatus showed that photosynthetic function was not impaired, though differences in development occurred.

Lichenoid reaction from a permanent red tattoo: has nickel a possible aetiologic role?

A 27-year-old man had been tattooed by a professional tattooist 8 months before presentation. He had a large polychrome tattoo over his right deltoid, in which numerous purplish pruriginous papules had persisted since a few weeks after tattooing, restricted to the red areas of the tattoo (Fig. 1). Patch tests with the Italian SIDAPA series showed a ππ π D2/ππ π D3 reaction to nickel sulfate. A strong ππ D2/ππ π D3 reaction was also obtained to the original ‘cardinal red’ pigment used to tattoo the red areas. Patch tests with cobalt sulfate 2% pet., cadmium sulfate 2% pet., ammoniated mercury 1% pet. and copper sulfate 1% aqueous were all negative. A skin biopsy of the red papular lesions showed a bandlike dense lymphocytic infiltrate in the superficial dermis, focal liquefaction degeneration in the basal layer, exocytosis and occasional colloid bodies. There were numerous macrophages containing small pigment granules in the infiltrate. The clinical features, patch tests and biopsy led us to diagnose a chronic lichenoid allergic contact dermatitis due to the red pigment of the tattoo. The material safety data sheet of the ‘cardinal red’ dye declared monoazo pigment, cinnabar and traces of the heavy metals lead, mercury, cadmium, chromium and selenium, but no nickel. Further investigation was therefore performed. After microwave acid digestion, graphite furnace atomic absorption spectroscopy of the original red dye was performed on 3 parts of the sample, which demonstrated the presence of nickel at 1.90 ∫ 0.34 ppm in the pigment. Treatment with a potent topical corticosteroid 2¿ daily for 2 months only slightly improved the dermatitis.

Cisplatin cytotoxicity in organ of corti-derived immortalized cells

Cisplatin is an anticancer drug currently used in the treatment of genital and head and neck tumors. Its use in these and other types of tumors is narrowed by onset of chemoresistance and severe undesired side effects, like as nephro‐ and ototoxicity, whose mechanisms of action are only partially understood. In the present study we investigated the effects of cisplatin (cis‐dichlorodiaminoplatin, CDDP) on a cell line (OC‐k3) developed from organs of Corti of transgenic mice. We observed at 48 h that cell death due to cisplatin was time and concentration‐dependent. The cell death displayed some morphological hallmarks of apoptosis, including nuclear fragmentation into several large nuclear fragments, surrounded by a rearranged and thickened actin cytoskeleton. No DNA laddering was detected, suggesting absence of endonuclease activity, nor annexin V positivity, suggesting absence of phosphatidylserine externalization. Several molecules protected the cells against CDDP induced cytotoxicity, including methionine, suramin and PD98059. Methionine reduced CDDP‐uptake, while suramin, a polycathionic compound a specifically binding external proteins, did not. This finding suggested that suramin could exert its protective effect by acting on an intracellular transduction pathway. We tested this hypothesis by studying the effect of suramin and PD98059, a MEK inhibitor, on the mitogen activated protein kinase (MAPK) cascade. After CDDP treatment, we found an increase of phosphorylation of extracellular regulated kinases (ERK)1/2, that could be inhibited by PD98059 and suramin. These data suggest that ERK pathways can play a role in mediating the cell death induction in presence of a CDDP challenge. J. Cell. Biochem. 101:1185–1197, 2007.

Adaptive modifications of the photosynthetic apparatus in Euglena gracilis Klebs exposed to manganese excess

Summary.Asynchronous cultures of wild-type Euglena gracilis were tested for their morphophysiological response to 10 mM MnSO4. Growth was only moderately slowed (15%), while oxygen evolution was never compromised. Inductively coupled plasma analyses indicated that the Mn cell content doubled with respect to controls, but no signs of localised accumulation were detected with X-ray microanalysis. Evident morphological alterations were found at the plastid level with transmission electron microscopy and confocal laser scanning microscopy. An increase in the plastid mass, accompanied by frequent aberrations of chloroplast shape and of the organisation of the thylakoid system, was observed. These aspects paralleled a decrease in the molar ratio of chlorophyll a to b and an increase in the fluorescence emission ratio of light-harvesting complex II to photosystem II, the latter evaluated by in vivo single-cell microspectrofluorimetry. These changes were observed between 24 and 72 h of treatment. However, the alterations in the pigment pattern and photosystem II fluorescence were no longer observed after 96 h of Mn exposure, notwithstanding the maintenance of the large plastid mass. The response of the photosynthetic apparatus probably allows the alga to limit the photooxidative damage linked to the inappropriately large peripheral antennae of photosystem II. On the whole, the resistance of Euglena gracilis to Mn may be due to an exclusion–tolerance mechanism since most Mn is excluded from the cell, and the small amount entering the organism is tolerated by means of morphophysiological adaptation strategies, mainly acting at the plastid level.

A new strategy for pressed powder eye shadow analysis: Allergenic metal ion content and particle size distribution

Nine cheap eye shadow products were analyzed through graphite furnace atomic absorption spectrometry (GF-AAS) to quantify their Cr, Co and Ni contents, all known to be skin sensitizers. In many cases, the concentrations were higher than 1 or 5 ppm (μg/g), i.e. the limits recommended in the scientific literature to minimize the risk of reaction in particularly sensitive subjects. In most cases, the concentration of Cr was higher than that of Ni and Co, up to a limit case of 150 mg/g. In this particular sample, the potential amount of Cr that could be released in ionic form was determined in sweat simulating solutions by GF-AAS and confirmed through a specific spectrofluorimetric method; the results indicated the presence of approximately 80-90 ppb (ng/g) of Cr(3+). The water dispersible particles were isolated from the eye shadow powders through a simple solvent extraction procedure. The aqueous suspensions were then sorted through sedimentation field flow fractionation (SdFFF) and the particles sizes were calculated from experimental fractograms using theory. For the most part, the computed sizes were in the micron range, as confirmed by some SEM photographs taken on fractions collected during the separations. The SdFFF coupled off-line with the GFAAS enabled elemental characterization of pigment particles as a function of size. This finding reduces the concern that the ingredients of such makeup formulations may contain nanoparticles.

The composition of PM1 and PM2.5 samples, metals and their water soluble fractions in the Bologna area (Italy)

Abstract In this study the metal composition of PM 1 and PM 2.5 samples collected in the surroundings of a municipal incinerator located in a suburban–farming area, less than 10 km away from Northeast of Bologna (Italy) was investigated. Seven out of eight monitoring stations were installed in a domain of 8x9 km 2 around the incinerator plant; the eighth station was placed inside the urban area of Bologna. The coordinates of four monitoring stations were selected on the basis of a preliminary study by using a dispersion model. Eleven metals (Al, Sb, As, Cd, Fe, Mn, Ni, Pb, Cu, V, Zn) were quantified in both the filter acid–digests and in the water extracts. The PM 2.5 collected in all the sites of the domain were highly correlated with exception of the urban site. The daily average metal concentrations in summer were 1.84% and 1.14% for PM 2.5 and PM 1 respectively, indicating that fine particles are less enriched in metals. Fe, Al and Zn were the most abundant elements, and they represented about the 80% of the total amount of the analyzed ones. The average water soluble metal compositions were 0.71% and 0.41% for PM 2.5 and PM 1 respectively. In the sites of the suburban–farming studied area the Principal Component Analysis (PCA) and Cluster Analysis revealed differences between water soluble metal compositions in PM 1 and PM 2.5 . The urban sites were characterized by lower total and soluble metals contents than the other PM 2.5 stations installed around the incinerator plant. However, no noticeable difference in the concentrations of metals in the particulate matter between the sites chosen as maxima of incinerator emissions and the control sites was observed.

Lipid-based nanoparticles containing cationic derivatives of PTA (1,3,5-triaza-7-phosphaadamantane) as innovative vehicle for Pt complexes: Production, characterization and in vitro studies

The aliphatic phosphine PTA (1,3,5-triaza-7-phosphaadamantane) is a promising ligand for metal complexes designed and developed as innovative inorganic drugs. In the present paper, an N-alkylated derivative of PTA, (PTAC16H33)X (X=I, C1, or X=PF6, C2) and its platinum coordination complex cis-[PtCl2(PTAC16H33)2](PF6)2, C3, were considered as components of cationic lipid nanoparticles (CLNs). Particularly, CLN1, CLN2 and CLN3 were obtained by adding derivatives C1, C2 or C3 during nanoparticles preparation, while CLN2-Pt were obtained by treating preformed CLN2 with Pt(II). It was demonstrated that CLN1, CLN2 and CLN3 can be produced with technological conventional methods. However, among the two here proposed protocols, the one based on the treatment of preformed nanoparticles appears more advantageous as compared to the other since it allows a quantitative association yield of Pt. As determined by ICP-OES, a content of P and Pt 2.2-fold and 2.5-fold higher in CLN2-Pt than in CLN3 was evidenced. For the first time was demonstrated that properly functionalized preformed nanoparticles can be efficiently used to obtain a post production Pt(II) complex while maintaining a cytotoxic activity toward cultured cells. In fact, the antiproliferative activity shown by CLN3, CLN2-Pt on the three model cancer cell lines was substantially similar and comparable to that of complex C3 in dmso solution. Thus N-alkylated-PTA derivatives in CLNs could be proposed as innovative biocompatible and water dispersible nanoparticles carrying lipophilic Pt complexes becoming an interesting and improved system with respect to dmso solution.

Allergic Contact Dermatitis Caused by Metals in Blackboard Chalk: A Case Report

© 2012 The Authors. doi: 10.2340/00015555-1296 Journal Compilation