Winsor & Newton original handbooks: asurface-enhanced Raman scattering (SERS) andRaman spectral database of dyes from modernwatercolor pigments

Background Winsor & Newton Ltd. has been one of the main fine art products providers since its establishment in 1832, being responsible for the manufacture of a wide assortment of materials ranging from oils and pigments to brushes and papers. All the items produced over the years have been indexed in a comprehensive historical archive. Original Winsor & Newton handbooks are a powerful resource which can offer insight into the world of artists’ materials, and knowledge of artists’ choices through the identification of substances employed to obtain particular colors. Scientific analyses of various kinds have been carried out on Winsor & Newton art materials over the years; however, a detailed study of the organic dyes contained in the watercolors manufactured by the company has never been performed thus far to our knowledge. Results In the present study, we examined a number of color washes on drawing paper from two historical Winsor & Newton catalogues dating to the 19th and 20th century. An appropriate database was thus built, including surface-enhanced Raman scattering (SERS) and Raman spectra of organic colorants from a wide variety of shades. While the selection of colors offered by the company in the 19th century mostly included lakes prepared from plant and insect dyes, i.e. madder and cochineal, some tints based on synthetic dyes were also found in the 20th century handbook. Conclusions The present article sheds new light on the chemical composition of a number of original Winsor & Newton color washes in terms of organic colorants contained in each shade. A special attention was dedicated to the analysis of those colors for which the formulation was ambiguous or not specified by the manufacturers, such as dragons’ blood and most of the alizarin-based pigments. In addition, we were able to correct erroneous indications provided by Winsor & Newton on the composition of some tints, as in the case of violet carmine, and study how the formulation of certain pigments has been modified over the centuries

Methodological evolutions of Raman spectroscopy in art and archaeology

During the last decades, Raman spectroscopy has grown from research laboratories to a well-established approach that is increasingly often used in archaeometry and conservation science

Technical note: Identification of Prototheca species from bovine milk samples by PCR-single strand conformation polymorphism

We report the development of a PCR-single strand conformation polymorphism (SSCP) method to identify Prototheca spp. responsible for bovine mastitis: P. zopfii and P. blaschkeae. The method was set up using reference strains belonging to P. zopfii genotype 1, P. zopfii genotype 2, and P. blaschkeae as target species and P. stagnora, and P. ulmea as negative controls. The assay was applied on 50 isolates of Prototheca spp. isolated from bovine mastitic milk or bulk-tank milk samples, and all isolates were identified as P. zopfii genotype 2. We conclude that the described PCR-SSCP approach is accurate, inexpensive, and highly suitable for the identification of P. zopfii genotype 2 on field isolates but also directly on milk, if preceded by a specific DNA extraction method

Recent Advances on the Analysis of Polychrome Works of Art: SERS of Synthetic Colorants and Their Mixtures With Natural Dyes

The development and application of proper sample pretreatments is often a key step toward the successful analysis of dyes used as artists' materials by surface-enhanced Raman spectroscopy (SERS). Complexation of the organic colorants with metal ions to dye fabrics and produce lake pigments, as well as undesired interactions with other matrix components such as substrate, binding media, fillers, and extenders, are just some of the issues that typically complicate dye identification in minute samples from invaluable artworks and museum objects. These concerns may be addressed by using, prior to SERS analysis, ad-hoc sample pretreatments that, in addition to increasing the technique's sensitivity, favorably affect its selectivity toward certain molecules or molecular classes. The present work describes a newly developed sample pretreatment based on the use of nitric acid that has proven crucial for the successful detection of aniline and xanthene dyes–the first synthetic organic colorants to be used in printing and painting, among other art forms–in microscopic samples from works of art such as a 19th-century silk fabric, paper cut-outs by Henri Matisse, Vincent Van Gogh's Irises, and Japanese woodblock prints. This treatment promotes the hydrolysis of the dye-metal bond in mordant dyes or lake pigments, resulting in a more efficient adsorption of the dye molecules on the SERS-active substrate and, hence, enabling the acquisition of high-quality spectra. In the case of synthetic colorants, this method shows advantages over hydrolysis with hydrofluoric acid–a procedure previously established for the analysis of red lakes prepared from natural dyes. The nitric acid treatment presented here may be integrated into a multi-step methodology that, by exploiting differences in solubility of various dyes and lake pigments, has enabled for the first time to successfully characterize intentional mixtures of natural and synthetic colorants of the xanthene and anthraquinone molecular classes, i.e., eosin Y and carmine, in a selection of Japanese prints of the Meiji era. The present study paves the way for the systematic identification of synthetic dyes in objects of artistic and archeological interest, even when they are present in mixtures with natural organic colorants

tracing history through luxury pink colors

The authors would like to thank José Alberto Ribeiro, director of Palácio Nacional da Ajuda, and Cristina Pinto Basto, coordinator librarian, for their generous support and rewarding collaboration. We also wish to acknowledge the Laboratory of Biopolymers—Centro de Investigación en Alimentación y Desarrollo, A.C (C.I.A.D., A.C.), Hermosillo, Sonora, México, for providing the samples of mesquite gum used in this work. This research was funded by the Portuguese Science Foundation (Fundação para a Ciência e Tecnologia, Ministério da Educação e da Ciência, FCT/MCTES) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007265). Project “Try it and you will see that is true”. Recipes and knowledge from Medieval society to the 21th century”, PID2019-108736GB-I00, Ministerio de Ciencia e Innovación. R. J. Díaz Hidalgo, posdoctoral UCO 2020, La producción documental y libraría al Ándalus siglos XIII XV, Plan Propio de Investigación de la Universidad de Córdoba; Publisher Copyright: © 2023, The Author(s).The Ajuda Songbook is an exceptional illuminated manuscript being the only surviving codex of Galician-Portuguese secular poetry; it was produced in the end of the thirteenth century, beginning of the fourteenth century. The diversity of colors accentuated by the presence of lapis lazuli blue and brazilwood pink, demonstrates the desire to produce a sumptuous manuscript. Pink is, in this context, a luxury color and its identification attests to one of the earliest known occurrences of brazilwood in artworks. Scientific analysis showed, for the light pinks, a different formulation from that found in fifteenth-century books of hours and from all historical reconstructions of these colors prepared to date. This knowledge was used to further expand a database previously built in our laboratory and applied to the characterization of pink shades in the Ajuda Songbook. Thirteen brazilwood recipes were selected from seven Medieval treatises and reference materials were prepared based on such historical information. Three types of colors were achieved, defined as translucent rose, rose, and red. The translucent rose was obtained from recipes where egg white is used for extraction, and no other additives are present; rose from recipes with calcium carbonate; and red from a wider range of recipes, in which these ingredients are not mentioned. These colors were then prepared as paints, and analytical results were thus compared with data from the light pinks seen in the Ajuda Songbook’s architectural backgrounds. We were able to reproduce the pink very well using infrared spectroscopy, identifying its main ingredients: calcium carbonate as filler; lead white as the pigment that produces light pink; and the binder as a polysaccharide with a fingerprint similar to mesquite gum. For the chromophore color, the application of chemometrics approaches to molecular fluorescence spectra highlighted a high degree of similarity with the paint reconstructions.publishersversionpublishe

Exploiting the bile acid binding protein as transporter of a Cholic Acid/Mirin bioconjugate for potential applications in liver cancer therapy

Bioconjugation is one of the most promising strategies to improve drug delivery, especially in cancer therapy. Biomolecules such as bile acids (BAs) have been intensively explored as carriers, due to their peculiar physicochemical properties and biocompatibility. BAs trafficking is regulated by intracellular lipid-binding proteins and their transport in the liver can be studied using chicken liver Bile Acid-Binding Proteins (cL-BABPs) as a reference model. Therefore, we conceived the idea of developing a BA-conjugate with Mirin, an exonuclease inhibitor of Mre11 endowed with different anticancer activities, to direct its transport to the liver. Following computational analysis of various BAs in complex with cL-BABP, we identified cholic acid (CA) as the most promising candidate as carrier, leading to the synthesis of a novel bioconjugate named CA-M11. As predicted by computational data and confirmed by X-ray crystallographic studies, CA-M11 was able to accommodate into the binding pocket of BABP. Hence, it can enter BAs trafficking in the hepatic compartment and here release Mirin. The effect of CA-M11, evaluated in combination with varying concentrations of Doxorubicin on HepG2 cell line, demonstrated a significant increase in cell mortality compared to the use of the cytotoxic drug or Mirin alone, thus highlighting chemo-sensitizing properties. The promising results regarding plasma stability for CA-M11 validate its potential as a valuable agent or adjuvant for hepatic cancer therapy

Aiding the conservation of two wooden Buddhist sculptures with 3D imaging and spectroscopic techniques

The conservation of Buddhist sculptures that were transferred to Europe at some point during their lifetime raises numerous questions: while these objects historically served a religious, devotional purpose, many of them currently belong to museums or private collections, where they are detached from their original context and often adapted to western taste. A scientific study was carried out to address questions from Museo d'Arte Orientale of Turin curators in terms of whether these artifacts might be forgeries or replicas, and how they may have transformed over time. Several analytical techniques were used for materials identification and to study the production technique, ultimately aiming to discriminate the original materials from those added within later interventions

Erratum to: Integrated molecular dissection of the epidermal growth factor receptor (EGFR) oncogenic pathway to predict response to EGFR-targeted monoclonal antibodies in metastatic colorectal cancer

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Characterization of the Proinflammatory Profile of Synovial Fluid-Derived Exosomes of Patients with Osteoarthritis

The purpose of this study is to characterize synovial fluid- (SF-) derived exosomes of patients with gonarthrosis comparing two methods of isolation and to investigate their immune regulatory properties. Extracellular vesicles (EVs) have been isolated from inflamed SF by polymer precipitation method and quantified by Exocet kit and by nanoparticle tracking analysis. Vesicles expressed all the specific exosomal markers by immunoblot and FACS. After isolation with Exoquick, a relevant contamination by immune complexes was detected, which required further magnetic bead-based purification to remove. SF-derived exosomes significantly stimulated the release of several inflammatory cytokines and chemokines and metalloproteinases by M1 macrophages but did not influence the expression of CD80 and CD86 costimulatory molecules. In conclusion, we characterized purified exosomes isolated from inflamed SF and demonstrate that purified exosomes are functionally active in their ability to stimulate the release of proinflammatory factors from M1 macrophages. Our data indicate that SF-derived exosomes from gonarthrosis patients play a role in disease progression