A methodological approach for quantifying aerial formaldehyde released by some hair treatments-modeling a hair-salon environment.

Formaldehyde is a well-known toxic agent, therefore having a highly regulated status. Despite, some cosmetic firms recently introduced high and illegal concentrations of formaldehyde in hair treatments for increasing straightening and long-lasting performances. The objective of this study was to assess how and to which extent, these products may disperse formaldehyde in the environment of a hair salon, possibly exposing the consumer and the hair professional technician to hazardous airborne amounts of formaldehyde. A laboratory room was equipped with three air pumps located at three locations: close to the heads of a mannequin, nearby the hair technician and the whole volume of the room. Pumps were connected to cartridges apt at trapping airborne formaldehyde. The latter was further quantified through an HPLC procedure.As compared to hair treatments free from formaldehyde that do not modify the airborne formaldehyde levels, products with a high concentration of formaldehyde (1.7% and 9.3%) disperse this compound in the environment to a high and hazardous concentration, detrimental to both consumer and hair professional. The brushing procedure on the hair led to a much higher dispersion of airborne formaldehyde than the hair straightening/ironing technique. To conclude, the use of hair treatments that contain high and illegal amounts of formaldehyde creates a hazardous environment to all people present within a hair salon.Implications: This methodology adopted here might be used to evaluate during conception phase the level of Formaldehyde release and be used as part of safety data for the registration. However, the present work also strongly promotes the adoption of electronic detectors (commercially available) that continuously record the aerial concentration of Formaldehyde, when dealing with hair styling products that contain legal or illegal (> 0.2%w/w) content of Formaldehyde These detectors not only cover an adequate and realistic range of aerial Formaldehyde but can be used and transported at different locations of a given space. Such a cautious measure comes from common sense as it relates to the health status of consumers and operators present in a hair salon environment.

Single step patterning of molecularly imprinted polymers for large scale fabrication of microbiochips.

We use photolithography to pattern molecularly imprinted polymers for the wafer-scale production of biochips. We are able to produce multiplexed, spatially resolved micrometer-sized features of functional materials capable of molecular recognition. Using a fluorescent probe, dansyl-L-Phe, we show specific analyte binding to MIP patterns imprinted with boc-L-Phe, by fluorescence microscopy. Advantages of this technique are the control of shape and size of the patterns with a resolution of 1.5 microm, and the possibility of depositing a number of different MIPs on the same chip (parallelization). Multiplexing chips on the same substrate paves the road to their mass-production. Because of the simplicity of the method and the low cost of chip fabrication, we believe that mass production of portable microbiochips based on stable MIPs is now in close reach. Their combination with integrated transducers fabricated by micromachining techniques appears also possible.

New developments in MALDI imaging for pathology proteomic studies.

With new emerging mass spectrometry technologies, it can now be demonstrated that direct tissue analysis is feasible using matrix-assisted laser desorption/ionization (MALDI) sources. A major advantage of direct MALDI analysis is to avoid time-consuming extraction, purification or separation steps, which have the potential for producing artifacts. Direct MALDI analysis of tissue sections enables the acquisition of cellular expression profiles while maintaining the cellular and molecular integrity. With automation and the ability to reconstruct complex spectral data using imaging software, it is now possible to produce multiplex imaging maps of selected bio-molecules within tissue sections. Thus, direct MALDI spectral data obtained from tissue sections can be converted into imaging maps, a method now known as MALDI-imaging. MALDI-imaging combines the power of mass spectrometry, namely exquisite sensitivity and unequivocal structural information, within an intact and unaltered morphological context. Critical improvements to increase image resolution are presented in this manuscript e.g., solvent treatment, new solid ionic matrices, gold sputtering, nickel support or laser focalization. One of the most important developments is the ability to carry out either direct MALDI analysis or MALDI imaging on paraffin tissue sections, thus opening the path to an archival "gold-mine" of existing pathology samples to proteomic analysis. These developments provide new avenues for biomarker hunting and diagnostic follow-up in the clinical setting. Further developments in MALDI-imaging of specific targets provide an added dimension, as validated disease-marker-gene RNA transcripts can be analyzed along with their translation by targeting their specific protein products or metabolites. Disease/health states will thus be closely molecularly monitored at protein and nucleic acids levels, with a single technique. Taken together, MALDI imaging will become a key tool for pathology proteomic studies.

Specific MALDI imaging and profiling for biomarker hunting and validation: fragment of the 11S proteasome activator complex, Reg alpha fragment, is a new potential ovary cancer biomarker.

MALDI imaging mass spectrometry represents a new analytical tool to directly provide the spatial distribution and relative abundance of proteins in tissue. Twenty-five ovary carcinomas (stages III and IV) and 23 benign ovaries were directly analyzed using MALDI-TOF MS. The biomarker with the major prevalence (80%) has been fully identified using MALDI MS and nanoESI MS and MS/MS after separation by RP-HPLC and trypsin enzymatic digestion. This marker with an m/z of 9744 corresponds to 84 amino acid residues from the 11S proteasome activator complex, named PA28 or Reg-alpha. Validation of this marker has been performed using MALDI imaging, classical immunocytochemistry with an antibody raised against the C-terminal part of the protein, specific MALDI imaging, and Western blot analysis. The validation, using immunocytochemistry, confirmed the epithelial localization of this fragment with nucleus localization in benign epithelial cells and a cytoplasmic localization in carcinoma cells. This indicates that this antibody could be used to discriminate the borderline tumor cases. At this point, a multicentric study needs to be conducted in order to clearly establish the potential of this biomarker. Taken together these studies reflect that direct tissue analysis and specific MALDI imaging strategies facilitate biomarker hunting and validation which can be named pathological proteomics.

[MALDI imaging: a new technology to discover and validate new biomarkers]. / Imagerie MALDI: une nouvelle technologie pour découvrir et valider de nouveaux biomarqueurs.

Within the growing field of proteomics, mass spectrometry is now established as a powerful tool for peptide and protein identification and discovery from purified samples. A new era is now beginning, with the development of MALDI imaging, maintaining the sensitivity and efficacy of both discovery and identification while additionally preserving the anatomical integrity of biomolecules like peptides, proteins, oligonucleotides and lipids within tissues. Crucial developments for sample preparations have made leaps and bounds, as it is now possible to work with freezed conserved biopsies (- 80 degrees c) of more than 6 months or even conserved after paraformaldehyde fixation and paraffin embedding. The latter development has opened the door to archived tissues in hospital libraries and biomarkers hunting from tissues derived from these libraries are now a key objective. The relationship between MALDI imaging and immunocytochemistry used by the pathologist is important. The development of specific MALDI imaging using probes with a tag (peptide or organic) called << Tag-Mass >> adds a whole new perspective. It is possible henceforth to localize a protein with its specific mRNA and more specifically, with its signalling pathway on the same sections or within a pathology expression phenotype from a biopsy. Development of such a technology is similar to the one that occurred several years ago for nuclear magnetic resonance (NMR) that leads the development of imaging technologies called MRI in hospital which is intensively used for pathology diagnostics.

Molecular profiling of native and matrix-coated tissue slices from rat brain by infrared and ultraviolet laser desorption/ionization orthogonal time-of-flight mass spectrometry.

Phospho- and glycolipids contained in the plasma membrane of neuronal tissue were profiled by direct infrared laser desorption/ionization orthogonal time-of-flight mass spectrometry (IR-LDI-o-TOF-MS), performed on cryosected native slices generated from rat brain. About 100 different detected lipid species are putatively assigned based on their molecular weight. Spraying of potassium acetate onto the slices was found to facilitate data interpretation in positive ion mode by reducing residual sodium adduct ion intensities. Coating the slices with matrix and using an ultraviolet laser for UV-MALDI-o-TOF-MS extends the analysis to peptides and small proteins but induces analyte diffusion. Peptides and partially cleaved proteins derived from proteolytic digests were recorded after incubation of native sections with trypsin and subsequent coating of the slices with MALDI matrix.