Rational modification of estrogen receptor by combination of computational and experimental analysis

In this manuscript, we modulate the binding properties of estrogen receptor protein by rationally modifying the amino acid composition of its ligand binding domain. By combining sequence alignment and structural analysis of known ER-ligand complexes with computational analysis, we were able to predict ER mutants with altered binding properties. These predictions were experimentally confirmed by producing single point variants with up to an order of magnitude increased binding affinity towards some estrogen disrupting chemicals and reaching an IC50 value of 2 nM for the 17α−Ethinylestradiol ligand. Due to increased affinity and stability, utilizing such mutated ERs instead of the wild type ER as bio-recognition element would be beneficial in an assay or biosensor.JRC.I-Institute for Health and Consumer Protection (Ispra

Towards a review of the EC Recommendation for a definition of the term "nanomaterial" Part 2: Assessment of collected information concerning the experience with the defintion

This report provides the JRC assessment of feedback on the experiences of stakeholders with the EC nanomaterial definition, published in 2011 (EC Recommendation 2011/696/EU). The report is a follow-up report of the previous JRC report (EUR 26567 EN, 2014), which compiled feedback collected by JRC in 2013 and early 2014, partly through a dedicated survey. Based on the current report, JRC will prepare a set of recommendations for the revision of the EC nanomaterial definition, as part of the review process foreseen in the 2011 EC Recommendation.JRC.D.2-Standards for Innovation and sustainable Developmen

Towards a review of the EC Recommendation for a definition of the term "nanomaterial"; Part 1: Compilation of information concerning the experience with the definition

In October 2011 the European Commission (EC) published a Recommendation on the definition of nanomaterial (2011/696/EU). The purpose of this definition is to enable determination when a material should be considered a nanomaterial for regulatory purposes in the European Union. In view of the upcoming review of the current EC Definition of the term 'nanomaterial' and noting the need expressed by the EC Environment Directorate General and other Commission services for a set of scientifically sound reports as the basis for this review, the EC Joint Research Centre (JRC) prepares three consecutive reports, of which this is the first. This Report 1 compiles information concerning the experience with the definition regarding scientific-technical issues that should be considered when reviewing the current EC definition of nanomaterial. Based on this report and the feedback received, JRC will write a second, follow-up report. In this Report 2 the JRC will provide a detailed assessment of the scientific-technical issues compiled in Report 1, in relation to the objective of reviewing the current EC nanomaterial definition.JRC.I.4-Nanobioscience

Determination of the structure and morphology of gold nanoparticle–HSA protein complexes

A method to measure the number of proteins bound to each nanoparticle and changes in the protein structure is reported

Targeting of Basophil and Mast Cell Pro-Allergic Reactivity Using Functionalised Gold Nanoparticles

Calcineurin inhibitors potentially prevent pro-allergic mediator release from basophils and mast cells but are rarely used systemically due to ubiquitous expressions of target signaling proteins. However, specific targeting of allergic effector cells with these inhibitors could circumvent unwanted side effects. We recently demonstrated the biocompatibility of gold nanoparticles (AuNPs) as a platform for non-toxic delivery of signaling inhibitors due to unique physicochemical properties of these nanomaterials. Since AuNPs can be conjugated with both anti-allergic drugs and antibodies or other proteins that specifically recognize basophils and mast cells, our aims were to assess specific targeting of allergic effector cell function using AuNPs conjugated with the calcineurin inhibitor ascomycin. Purified human basophils and LAD2 human mast cells were used for investigations with AuNPs conjugated either to CD203c antibodies or containing stem cell factor (SCF), respectively, which were amine-coupled to acidic groups of reduced glutathione (GSH). GSH was also used as a spacer for immobilization of ascomycin on the gold surface. AuNPs conjugated with anti-CD203c and ascomycin strikingly blocked IgE-dependent degranulation of both purified basophils and those present in mixed leukocyte preparations, suggesting specific targeting of these cells. In contrast, LAD2 mast cell responses were not inhibited using anti-CD203c-containing nanoconjugates but were when the conjugates contained SCF. Successful targeting of allergic effector cells using gold nanoconjugates indicates that this technology may have therapeutic potential for the treatment of allergies by specifically delivering highly effective signaling inhibitors with reduced side effects

Monitoring Anti-PEG Antibodies Level upon Repeated Lipid Nanoparticle-Based COVID-19 Vaccine Administration

PEGylated lipids are one of the four constituents of lipid nanoparticle mRNA COVID-19 vaccines. Therefore, various concerns have been raised on the generation of anti-PEG antibodies and their potential role in inducing hypersensitivity reactions following vaccination or in reducing vaccine efficacy due to anti-carrier immunity. Here, we assess the prevalence of anti-PEG antibodies, in a cohort of vaccinated individuals, and give an overview of their time evolution after repeated vaccine administrations. Results indicate that, in our cohort, the presence of PEG in the formulation did not influence the level of anti-Spike antibodies generated upon vaccination and was not related to any reported, serious adverse effects. The time-course analysis of anti-PEG IgG showed no significant booster effect after each dose, whereas for IgM a significant increase in antibody levels was detected after the first and third dose. Data suggest that the presence of PEG in the formulation does not affect safety or efficacy of lipid-nanoparticle-based COVID-19 vaccines

Agglomeration Behavior and Fate of Food-Grade Titanium Dioxide in Human Gastrointestinal Digestion and in the Lysosomal Environment

In the present study, we addressed the knowledge gaps regarding the agglomeration behavior and fate of food-grade titanium dioxide (E 171) in human gastrointestinal digestion (GID). After thorough multi-technique physicochemical characterization including TEM, single-particle ICP-MS (spICP-MS), CLS, VSSA determination and ELS, the GI fate of E 171 was studied by applying the in vitro GID approach established for the regulatory risk assessment of nanomaterials in Europe, using a standardized international protocol. GI fate was investigated in fasted conditions, relevant to E 171 use in food supplements and medicines, and in fed conditions, with both a model food and E 171-containing food samples. TiO2 constituent particles were resistant to GI dissolution, and thus, their stability in lysosomal fluid was investigated. The biopersistence of the material in lysosomal fluid highlighted its potential for bioaccumulation. For characterizing the agglomeration degree in the small intestinal phase, spICP-MS represented an ideal analytical tool to overcome the limitations of earlier studies. We demonstrated that, after simulated GID, in the small intestine, E 171 (at concentrations reflecting human exposure) is present with a dispersion degree similar to that obtained when dispersing the material in water by means of high-energy sonication (i.e., >70% of particles <250 nm)

Rational design of multi-functional gold nanoparticles with controlled biomolecule adsorption: a multi-method approach for in-depth characterization

Multi-functionalized nanoparticles are of great interest for diagnostic and therapeutic applications