• Paris, France
Recent publications
Background: Skin aging is a process regulated by chronological aging and amplified by exposome factors including chronic UV exposure and pollution, which both induce reactive oxygen species. Topical antioxidants have the potential to counteract this process and to improve skin aging signs, including wrinkles and hyperpigmentation. Objective: To evaluate the efficacy of a topical antioxidant serum containing 15% L-ascorbic acid, neohesperidin, Pinus pinaster bark, tocopherol and hyaluronic acid (HA) ex vivo on air pollution-induced pigmentation and gene expression, as well as in vivo on skin aging signs in Brazilian volunteers, after 90 days of use. Methods: Ex vivo human skin samples were repetitively exposed to Diesel Exhaust Particles (DEP) and subsequently analyzed for changes in pigmentation and gene expression. Clinical efficacy was evaluated in 40 healthy adult females with phototype II to IV and visible photoaging signs, including facial hyperpigmentation, through dermatological evaluation and instrumental analysis including Reflectance Confocal Microscopy. Results: Ex vivo, the topical anti-oxidant serum significantly reduced DEP-induced skin pigmentation and expression of proinflammatory genes. A significant improvement of skin aging signs was observed after 90 days. Local tolerance was good. Conclusion: The tested serum is effective in protecting human skin ex vivo against air pollution-induced skin pigmentation/aging and reduced in vivo skin aging signs, with a good safety profile after 90 days of daily use.
INTRODUCTION: Androgenic alopecia (AGA) is a common and chronic condition. It may impact self-esteem, self-image and quality of life. Benefit, tolerability, cosmetic acceptance and patient satisfaction are key to ensuring good treatment outcome. AIM: Assessment of hair loss improvement and hair quality with AC5 in subjects with mild AGA in real life settings. MATERIALS AND METHODS: Open-label, observational, international real-life study in 527 adult subjects with mild AGA who received AC5 (2,4-Diamino-Pyrimidine-N-Oxyde, arginine, 6-O glucose linoleate (SP94), piroctone olamine and Vichy mineralizing water) once daily for 3 months. After 3 months, investigators evaluated the impact of AC5 on hair loss and product satisfaction, and asked subjects about local tolerance; subjects assessed hair growth and quality, as well as satisfaction. RESULTS: Data from 357 subjects were evaluable for the benefit analysis; 59.9% of subjects were female; the mean age was 33.6±8.7 years. Duration of hair loss was 1.62±2.24 years. 71.3% of women had a Ludwig score of 1 and 40.8% of men had a Hamilton Norwood score of 2. At the end of study, hair loss was reduced in 89.0% of subjects; it was slightly higher in women (92.5%) than in men (83.8%). Subject satisfaction on a scale from 0 (not satisfied at all) to 10 (completely satisfied) was 7.9±1.7. Tolerance was rated good to very good by 98.6% of all subjects. CONCLUSION: AC5 reduces mild AGA in both men and women and has a pleasant texture. AC5 was well tolerated and highly appreciated.
Characterizing and understanding the viscoelastic mechanical properties of natural and synthetic fibers is of great importance in many biological and industrial applications. Microscopic techniques such as micro/nano indentation have been successfully employed in such efforts, yet these tests are often challenging to perform on fibers and come with certain limitations in the interpretation of the obtained results within the context of the macroscopic viscoelasticity in the fiber. Here we instead explore the properties of a series of natural and synthetic fibers, using a freely-oscillating torsional pendulum. The torsional oscillation of the damped mass-fiber system is precisely recorded with a simple HD video-camera and an image processing algorithm is used to analyze the resulting videos. Analysis of the processed images show a viscoelastic damped oscillatory response and a simple mechanical model describes the amplitude decay of the oscillation data very well. The natural frequency of the oscillation and the corresponding damping ratio can be extracted using a logarithmic decrement method and directly connected to the bulk viscoelastic properties of the fiber. We further study the sensitivity of these measurements to changes in the chemo-mechanical properties of the outer coating layers on one of the synthetic fibers. To quantify the accuracy of our measurements with the torsional pendulum, a complementary series of tests are also performed on a strain-controlled rheometer in both torsional and tensile deformation modes.
Motivation: The growing production of massive heterogeneous biological data offers opportunities for new discoveries. However, performing multi-omics data analysis is challenging, and researchers are forced to handle the ever-increasing complexity of both data management and evolution of our biological understanding. Substantial efforts have been made to unify biological datasets into integrated systems. Unfortunately, they are not easily scalable, deployable and searchable, locally or globally. Results: This publication presents two tools with a simple structure that can help any data provider, organization or researcher, requiring a reliable data search and analysis base. The first tool is Kibio, a scalable and adaptable data storage based on Elasticsearch search engine. The second tool is KibioR, a R package to pull, push and search Kibio datasets or any accessible Elasticsearch-based databases. These tools apply a uniform data exchange model and minimize the burden of data management by organizing data into a decentralized, versatile, searchable and shareable structure. Several case studies are presented using multiple databases, from drug characterization to miRNAs and pathways identification, emphasizing the ease of use and versatility of the Kibio/KibioR framework. Availability: Both KibioR and Elasticsearch are open source. KibioR package source is available at https://github.com/regisoc/kibior and the library on CRAN at https://cran.r-project.org/package=kibior. Supplementary information: Supplementary data are available at Bioinformatics online.
In response to biotic stress, plants produce suites of highly modified fatty acids that bear unusual chemical functionalities. Despite their chemical complexity and proposed roles in pathogen defense, little is known about the biosynthesis of decorated fatty acids in plants. Falcarindiol is a prototypical acetylenic lipid present in carrot, tomato, and celery that inhibits growth of fungi and human cancer cell lines. Using a combination of untargeted metabolomics and RNA sequencing, we discovered a biosynthetic gene cluster in tomato (Solanum lycopersicum) required for falcarindiol production. By reconstituting initial biosynthetic steps in a heterologous host and generating transgenic pathway mutants in tomato, we demonstrate a direct role of the cluster in falcarindiol biosynthesis and resistance to fungal and bacterial pathogens in tomato leaves. This work reveals a mechanism by which plants sculpt their lipid pool in response to pathogens and provides critical insight into the complex biochemistry of alkynyl lipid production.
Exposure information is a critical element in various regulatory and non-regulatory frameworks in Europe and elsewhere. Exposure science supports to ensure safe environments, reduce human health risks, and foster a sustainable future. However, increasing diversity in regulations and the lack of a professional identity as exposure scientists currently hamper developing the field and uptake into European policy. In response, we discuss trends, and identify three key needs for advancing and harmonizing exposure science and its application in Europe. We provide overarching building blocks and define six long-term activities to address the identified key needs, and to iteratively improve guidelines, tools, data, and education. More specifically, we propose creating European networks to maximize synergies with adjacent fields and identify funding opportunities, building common exposure assessment approaches across regulations, providing tiered education and training programmes, developing an aligned and integrated exposure assessment framework, offering best practices guidance, and launching an exposure information exchange platform. Dedicated working groups will further specify these activities in a consistent action plan. Together, these elements form the foundation for establishing goals and an action roadmap for successfully developing and implementing a 'European Exposure Science Strategy' 2020-2030, which is aligned with advances in science and technology.
Real-time facial projection mapping is a challenging problem due to the low system latency and the high spatial augmentation accuracy requirements. We propose a new compact and inexpensive projector-camera system (ProCam) composed of off-the-self devices that achieves dynamic facial projection mapping. A mini projector and a depth sensor camera are coupled together to project content on a user’s face. In one application, the camera tracks the facial landmarks of a person and simulated makeup is mapped on the person’s face. The latter is created by defining different zones of interest on the face. Instead of using sophisticated hardware, we propose an affordable system that can be easily installed anywhere while it assures an immerse experience. No initialization phase is needed and the system can handle different face topologies. In addition, the users can keep their eyes open and enjoy the projetion in a mirror.
We report a novel method for the reduction of α,β-unsaturated enones to the corresponding fully saturated alcohols in a single procedure. Remarkably, the method employs a heterogeneous copper catalyst in water and only requires resin-treatment for isolation of C-glycosidic alcohols as pure, diastereomeric mixtures. Our methodology was applied to the reduction of aromatic and aliphatic enones which furnished a library of C-glycosidic saturated alcohols from renewable sugars via a green and sustainable approach.
Drug development is currently hampered by the inability of animal experiments to accurately predict human response. While emerging organ on chip technology offers to reduce risk using microfluidic models of human tissues, the technology still relies on end-point assays to assess tissue damage resulting in limited mechanistic information and an inability to detect adverse effects occurring at sub-toxic drug exposure. Here we present a sensor-integrated liver on chip array in which oxygen is monitored using two-frequency phase modulation of tissue-embedded phosphorescent microprobes, while glucose, lactate and temperature are measured in real time using microfluidic electrochemical sensors. Our microphysiological platform permits the calculation of dynamic changes in metabolic fluxes around central carbon metabolism, producing a unique metabolic fingerprint of the liver’s response to stimuli. Using our platform, we studied the dynamics of human liver response to the epilepsy drug Valproate (Depakine™) and the antiretroviral medication Stavudine (Zerit™). Using E6/E7LOW hepatocytes we show TC50 of 2.5 and 0.8 mM, respectively, coupled with a significant induction of steatosis in 2D and 3D cultures. Time to onset analysis showed slow progressive damage starting only 15-20 hours post-exposure. However, flux balance analysis showed a rapid disruption of metabolic homeostasis occurring below the threshold of cellular damage. While Valproate exposure led to a sustained 15% increase in lipogenesis followed by mitochondrial stress, Stavudine exposure showed only a transient 5% increase in lipogenesis followed by its inhibition suggesting disruption of beta-oxidation. Our data demonstrates the importance of tracking metabolic stress as a predictor of clinical outcome.
Objective Oxidative stress and low grade chronic inflammation stand out as key features of physiological skin aging. The aim of this study was to examine in normal human epidermal keratinocytes (NHEK) and human dermal fibroblasts (HDF) grown in vitro, the antioxidant and anti‐inflammatory properties of crocin, a carotenoid glycoside responsible for the color of saffron. Moreover, considering the newly emerging field of skin glycobiology and the presence of two gentiobiosyl moieties in crocin, the effect of crocin on NHEK glycosylation pathways was for the first time investigated. Methods The anti‐inflammatory and anti‐oxidant activities of crocin were evaluated by in vitro assays of anti‐oxidation activities, Elisa assays and microarray analysis. The effect of crocin on keratinocyte glycobiology was evaluated by proprietary GLYcoDiag lectin technologies and microarray analysis. Results Crocin is endowed with antioxidant potential against ROS, protects squalene against UVA‐induced peroxidation and prevents the release of inflammatory mediators. The expression of NF‐kB related genes and glycosylation related genes is modulated in the presence of crocin. Conclusion Results could designate this molecule as a promising skin aging prevention cosmetic agent. Of note, some of these effects could be mediated by protein O‐glycosylation and interaction of crocin with osidic receptors of keratinocytes. This article is protected by copyright. All rights reserved.
Background: The glycosylation of proteins on the surface of corneocytes is believed to play an important role in cellular adhesion in the stratum corneum (SC) of human skin. Mapping with accuracy the localization of glycans on the surface of corneocytes through traditional methods of immunohistochemistry and electron microscopy remains a challenging task as both approaches lack enough resolution or need to be performed in high vacuum conditions. Materials and methods: We used an advanced mode of atomic force microscope (AFM), with simultaneous topography and recognition imaging to investigate the distribution of glycans on native (no chemical preparation) stripped samples of human SC. The AFM cantilever tips were functionalized with anti-heparan sulfate antibody and the lectin wheat germ agglutinin (WGA) which binds specifically to N-acetyl glucosamine and sialic acid. Results: From the recognition imaging, we observed the presence of the sulfated glycosaminoglycan, heparan sulfate, and the glycans recognized by WGA on the surface of SC corneocytes in their native state. These glycans were found associated with bead-like domains which represent corneodesmosomes in the SC layers. Glycan density was calculated to be ~1200 molecules/μm2 in lower layers of SC compared to an important decrease, (~106 molecules/μm2 ) closer to the surface due probably to corneodesmosome degradation. Conclusion: Glycan spatial distribution and degradation is first observed on the surface of SC in native conditions and at high resolution. The method used can be extended to precisely localize the presence of other macromolecules on the surface of skin or other tissues where the maintenance of its native state is required.
The assessment of complex mixture biodegradability can be limited by technical issues and/or difficulties to rule on ready or inherent biodegradability. This work is composed of three different studies to introduce and improve Ultimately Transformed Organic Carbon (UTOC) as a quantification tool for biodegradation. The UTOC includes the inorganic carbon resulting from respiration and the carbon assimilated by microorganisms. The UTOC is correlated with dissolved organic carbon removal and can be a robust alternative for non-soluble substance evaluation. The UTOC was evaluated using a complex mixture of soluble and non-soluble substances and verified with an UVCB (vegetal extract). The advantages of UTOC are clear; it is an appropriate method to quantify the initial raw material converted to an inert product by the action of microorganisms to determine the ready biodegradability of an unknown substance such as a vegetal extract.
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687 members
Matthieu Perrot
  • Research and Development
Bruno A Bernard
  • Research & innovation, Scientific Directorate
Gustavo S Luengo
  • Research and Development
Blaise Didillon
  • Research and Innovation
Paris, France