Université PSL

Publications

RECHERCHER

Laboratoire :
Auteur :
Revue :
Année :

A L'ATTENTION DES EQUIPES IPGG :

- Pour toute publication de résultats ayant reçu l’aide de l’IPGG (présence dans les locaux de l’IPGG, passage sur la plateforme technologique de l’IPGG, collaboration inter équipes IPGG, lié à une bourse doctorale ou postdoctorale IPGG, ou encore utilisation des espaces communs), il vous faut indiquer  cette phrase « Ce travail a été réalisé avec le soutien du laboratoire d’excellence Institut Pierre-Gilles de Gennes (programme Investissements d’avenir ANR-10-IDEX-0001-02 PSL et ANR-10-LABX-31). » / « This work has received the support of "Institut Pierre-Gilles de Gennes" (laboratoire d’excellence, “Investissements d’avenir” program ANR-10-IDEX-0001-02 PSL and ANR-10-LABX-31.). ».

- Pour toute publication de résultats obtenu via l'utilisation d’un équipement acheté par l’Equipex IPGG, il vous faut ajouter  la codification suivante : « ANR-10-EQPX-34 ».

Withdrawal and dip coating of an object from a yield-stress reservoir
Laboratoire Matériaux Innovants pour l'Energie - Wilbert J. Smit, Christophe Kusina, Annie Colin, Jean-François Joanny
Physical Review Fluids - 6(6) - DOI:10.1103/PhysRevFluids.6.063302 - 2021
The dip-coating process consists of withdrawing immersed objects from a liquid reservoir. After withdrawal, a significant layer of liquid remains on the object. Various industrial processes (food and beverage industry, automotive industry) use this technique to coat or treat surfaces. Recent studies have shown that the thickness of deposit is determined by the flow inside the reservoir for yield-stress fluids. This is different from the behavior of simple liquids for which the coating thickness is solely determined by the flow inside the meniscus. In this work, we reexamine this question and propose a complete phase diagram linking the Newtonian case and the yield-stress fluid case. We provide asymptotic scaling laws for extreme cases. A good agreement with experiments is obtained.
A new pressure sensor array for normal stress measurement in complex fluids
Laboratoire Matériaux Innovants pour l'Energie - Anaïs Gauthiera, Mickaël Pruvost, Olivier Gamache, and Annie Colin
Journal of Rheology - 65 583 - doi.org/10.1122/8.0000249 - 2021
A new pressure sensor array, positioned on the bottom plate of a standard torsional rheometer, is presented. It is built from a unique piezo-capacitive polymeric foam and consists of 25 capacitive pressure sensors (of surface 4.5×4.5mm2 each) built together in a 5×5 regular array. The sensor array is used to obtain a mapping of the normal stresses in complex fluids, which dramatically extends the capability of the rheometer. We demonstrate this with three examples. First, a pressure profile is reconstructed in a polymer solution, which enables the simultaneous measurement of the first and the second normal stress differences N1 and N2, with a precision of 2 Pa. In a second part, we show that negative pressures can also be measured. Finally, we focus on the normal stress fluctuations that extend both spatially and temporally in a shear-thickening suspension of cornstarch particles. We evidence the presence of a unique heterogeneity rotating very regularly. In addition to their low cost and high versatility, the sensors show here their potential to finely characterize the normal stresses in viscosimetric flows.
Aging of cornstarch particles suspended in aqueous solvents at room temperature
Laboratoire Matériaux Innovants pour l'Energie - Christophe Kusina, Wilbert J. Smit, Jean-Baptiste Boitte, Odile Aubrun, and Annie Colin
Phys. Rev. - 103 052609 - doi.org/10.1103/PhysRevE.103.052609 - 2021
Starch suspensions are often used as model systems to demonstrate extreme shear-thickening effects. We study the aging of cornstarch particles in aqueous suspensions at room temperature by granulometry and rheological measurements. When starch is diluted in glycerol, no long-term changes are observed. The situation differs when water is used as solvent. For volume fractions up to 20 vol %, when the cornstarch suspensions in water are stored under continual agitation, we observe an increase in viscosity. When the cornstarch suspension is aged under quiescent conditions, no evolution of the particle size is observed. In the concentrated situation, the rheological properties vary independent of the storage condition. We show that the increase in viscosity is related to air trapped in the pore space and to the swelling of the granules and leakage of the amylopectin component of the starch into the surrounding water. The relative importance of the two processes depends upon the particle concentration and upon the energy brought to the system
Highly conductive colloidal carbon based suspension for flow-assisted electrochemical systems
Laboratoire Matériaux Innovants pour l'Energie - Marco S. Alfonso, Hélène Parant, Jinkai Yuan, Wilfrid Neri, Eric Laurichesse, Katerina Kampioti, Annie Colin, PhilippePoulin
Iscience - 24(5) 102456 - doi.org/10.1016/j.isci.2021.102456 - 2021
Carbon suspension electrodes are promising for flow-assisted electrochemical energy storage systems. They serve as flowable electrodes in electrolyte solutions of flow batteries, or flow capacitors. They can also be used for other applications such as capacitive deionization of water. However, developments of such suspensions remain challenging. The suspensions should combine low viscosity and high electronic conductivity for optimized performances. In this work, we report a flowable aqueous carbon dispersion which exhibits a viscosity of only 2 Pa.s at a shear rate of 5 s−1 for a concentration of particles of 7 wt%. This suspension displays an electronic conductivity of 65 mS/cm, nearly two orders of magnitude greater than previously investigated related materials. The investigated suspensions are stabilized by sodium alginate and arabic gum in the presence of ammonium sulfate. Their use in flowable systems for the storage and discharge of electrical charges is demonstrated.
Highly conductive colloidal carbon based suspension for flow-assisted electrochemical systems
Laboratoire Matériaux Innovants pour l'Energie - Soufiane Abdelghani-Idrissi, Nicolas Dubouis, Alexis Grimaud, Philippe Stevens, Gwenaëlle Toussaint & Annie Colin
Scientific Reports volume - 11 4677 - https://doi.org/10.1038/s41598-021-84084-1 - 2021
In this study, the effect of flow of the electrolyte on an electrolysis cell and a zinc cell is investigated. The gain of energy brought by the flow is discussed and compared to the viscous losses in the cells. We point out that the balance between the gained electrical power and the viscous loss power is positive only if the hydrodynamic resistance of the circuit is correctly designed and further comment on the economical viability of the whole process. A model of the studied phenomena is proposed in the last section. This analytical model captures the dynamics of the process, gives the optimal flowing conditions and the limits of the energetical rentability of the process. This study shows that the use of flowing electrolyte in zinc–air batteries can be energetically profitable with the appropriate flowing conditions.

Can unmixed complex forming polymer surfactant formulations be injected into oil reservoirs or aquifers without clogging them?
Laboratoire Matériaux Innovants pour l'Energie - Massinissa Hamouma, Aline Delbos, Christine Dalmazzoneb and Annie Colin
Soft Matter - - doi.org/10.1039/D1SM00252J - 2021
In the context of enhanced oil recovery or soil remediation, we study the role of interactions between polymers and surfactants on the injectivity of formulations containing mixtures of polymers and surfactants. We show that contrary to the first intuition, the formation of aggregates in polymers surfactants formulations is not necessarily a hindrance to the injection of these formulations into pores. It is important above all to compare the size of aggregates according to the applied shear rate and the pore size to find the formulations that may induce clogging. We highlight a new positive and unexpected phenomenon. The small aggregates that do not lead to clogging ensure the transport of the surfactant vesicles in the porous medium and limit the adsorption of the latter.

Polymer Surfactant Interactions in Oil Enhanced Recovery Processes
Laboratoire Matériaux Innovants pour l'Energie - Massinissa Hamouma, Aline Delbos, Christine Dalmazzoneb and Annie Colin
Energy Fuels - 35(11) 9312–9321 - https://doi.org/10.1021/acs.energyfuels.1c00562 - 2021
A soil decontamination or enhanced oil recovery procedure typically requires the injection of a surfactant solution to reduce interfacial tension and promote oil recovery at the pore level, followed by the injection of a polymer solution to avoid the creation of preferential pathways and perform a homogeneous sweep of the reservoir. It is well known that polymers and surfactants interact with each other to form aggregates if they are of opposite charge or due to depletion interactions. To date, it is recommended to use polymers and surfactants that do not interact with each other to avoid clogging the wells. We show here that this precaution is not necessary and that in some cases, the use of interacting polymer and surfactant systems can even be an advantage for oil recovery. Contrary to previous studies, we injected previously mixed and homogeneous formulations into the porous medium and not a sequence of surfactant and polymer plugs. In addition to a total recovery of the oil in place, this strategy allows to limit the adsorption of the surfactant in the pore.


Reversible Supra-Folding of User-Programmed Functional DNA Nanostructures on Fuzzy Cationic Substrates
Laboratoire Nanobioscience et Microsystèmes group - Koyomi Nakazawa, Farah El Fakih, Vincent Jallet, Caroline Rossi-Gendron, Marina Mariconti, Léa Chocron, Mafumi Hishida, Kazuya Saito, Mathieu Morel, Sergii Rudiuk, Damien Baigl
Angew Chem Int Ed Engl - - DOI: 10.1002/anie.202101909 - 2021
We report that user-defined DNA nanostructures, such as two-dimensional (2D) origamis and nanogrids, undergo a rapid higher-order folding transition, referred to as supra-folding, into three-dimensional (3D) compact structures (origamis) or well-defined μm-long ribbons (nanogrids), when they adsorb on a soft cationic substrate prepared by layer-by-layer deposition of polyelectrolytes. Once supra-folded, origamis can be switched back on the surface into their 2D original shape through addition of heparin, a highly charged anionic polyelectrolyte known as an efficient competitor of DNA-polyelectrolyte complexation. Orthogonal to DNA base-pairing principles, this reversible structural reconfiguration is also versatile; we show in particular that 1) it is compatible with various origami shapes, 2) it perfectly preserves fine structural details as well as site-specific functionality, and 3) it can be applied to dynamically address the spatial distribution of origami-tethered proteins.
Synthesis and characterization of molecularly imprinted polymers for the selective extraction of oxazepam from complex environmental and biological samples
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Fanny Varenne, Porkodi Kadhirvel, Pauline Bosman, Loïc Renault, Audrey Combès, Valérie Pichon
Anal. Bioanal. Chem - - doi: 10.1007/s00216-021-03268-w. - 2021
Oxazepam, one of the most frequently prescribed anxiolytic drugs, is not completely removed from wastewater with conventional treatment processes. It can thus be found at trace levels in environmental water, with human urine constituting the major source of contamination. This study focused on the development and characterization of molecularly imprinted polymers (MIPs) for the selective solid-phase extraction of oxazepam at trace levels from environmental water and human urine samples. Two MIPs were synthesized, and their selectivity in pure organic and aqueous media were assayed. After optimizing the extraction procedure adapted to a large sample volume to reach a high enrichment factor, the most promising MIP was applied to the selective extraction of oxazepam from environmental water. Extraction recoveries of 83 ± 12, 92 ± 4 and 89 ± 10% were obtained using the MIP for tap, mineral and river water, respectively, while a recovery close to 40% was obtained on the corresponding non-imprinted polymer (NIP). Thanks to the high enrichment factors, a limit of quantification (LOQ) of 4.5 ng L-1 was obtained for river water. A selective extraction procedure was also developed for urine samples and gave rise to extraction recoveries close to 95% for the MIP and only 23% for the NIP. Using the MIP, a LOQ of 357 ng L-1 was obtained for oxazepam in urine. The use of the MIP also helped to limit the matrix effects encountered for the quantification of oxazepam in environmental samples and in human urine samples after extraction on an Oasis HLB sorbent.

Identification and semi-relative quantification of intact glycoforms of human chorionic gonadotropin alpha and beta subunits by nano liquid chromatography-Orbitrap mass spectrometry
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - AmiraAl Matari, Anastasia Goumenou, Audrey Combèsa, Thierry Fournier, Valérie Pichon, Nathalie Delaunay
J. Chromatography A - 1640 461945 - doi.org/10.1016/j.chroma.2021.461945 - 2021
The human chorionic gonadotropin (hCG) protein belongs to a family of glycoprotein hormones called gonadotropins. It is a heterodimer made of two non-covalently linked subunits. The α-subunit structure, hCGα, has 2 N-glycosylation sites, while the beta subunit, hCGβ, has 2 N- and 4 O-glycosylation sites. This leads to numerous glycoforms. A method based on the analysis of hCG glycoforms at the intact level by nano-reversed phase liquid chromatography coupled to high resolution mass spectrometry (nanoLC-HRMS) with an Orbitrap analyzer was previously developed using a recombinant hCG-based drug, Ovitrelle®, as standard. It allowed the detection of about 30 hCGα glycoforms, but didn't allow the detection of hCGβ glycoforms. This method was thus here significantly modified (addition of a pre-concentration step of the sample to increase the sample volume from 70 nl to 1 µl, optimization of the gradient slope and the nature and content of the acidic additive in the mobile phase). It led to an improvement of the separation of hCGα and hCGβ glycoforms, which allowed for the first time the detection of 33 hCGβ glycoforms at intact level. In addition, a higher number of hCGα glycoforms (42 in total, i.e. a 40% increase) was detected. The figures of merit of this new method were next assessed. The relative standard deviations (RSDs) of the retention time ranged between 0.02 and 0.95% (n = 3), with an average value of 0.36% for the alpha glycoforms and between 0.01 and 1.08% (n = 3) with an average value of 0.23% for the beta glycoforms. The RSDs of the relative peak area measured on the extracted ion chromatogram of each glycoform were below 20% (n = 3), with an average value of 9.8%, thus allowing semi-relative quantification. Therefore, this method has a high potential for rapid quality control aiming for the detection and comparison of glycoforms present in glycoprotein-based pharmaceutical preparations.


Development of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of tryptic digest of human hemoglobin exposed to sulfur mustard
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Florine Hallez, Audrey Combès, Charlotte Desoubries, Anne Bossée, Valérie Pichon
J. Chromatography A - 1163 122518 - doi.org/10.1016/j.jchromb.2020.122518 - 2021
Sulfur mustard is a highly reactive chemical warfare agent that causes severe damages to the victims exposed by alkylating multiple biomolecules such as proteins. Resulting alkylated products can be used as biomarkers of exposure to this chemical agent. A liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was thus developed to detect alkylated peptides after the tryptic digestion of hemoglobin (50 mg.mL−1) incubated with sulfur mustard at different concentrations (0.25, 0.5, 1, 10 and 100 µg.mL−1). Five new alkylation sites were accurately identified on the protein (α-His72, α-His87, α-His89, β-His2 and β-Val98) and fifteen adducted peptides were detected, among which eight of them resulted from the alkylation of four peptides, each presenting two potential sites of adduction that could be discriminated by the method specificity. Similarly, it was possible to discriminate the three potential adduction sites of the peptide α-T9. Moreover, the method allowed the quantification of all the alkylated peptides with a satisfying repeatability, with RSD ranging from 0.5 to 9.3% for an exposure of hemoglobin to sulfur mustard at 100 µg.mL−1. The analysis of hemoglobin incubated with different concentrations of sulfur mustard levels led to a linear response for all the alkylated peptides with the studied concentrations (0.25, 0.5, 1, 10 and 100 µg.mL−1). A variation of the alkylation rate was also observed between the different peptides studied, with a preferential adduction of sulfur mustard on the histidine residues but also on the N-terminal valine residues of both globin chains and on the Val98 residue of globin β. Furthermore, the presented method proved to be sensitive, with a theoretical possibility to detect alkylated peptides resulting from in vitro incubation of hemoglobin in deionized water with sulfur mustard at 2.63 ng.mL−1. After further development, this method could potentially be used for the analysis of blood samples in vivo exposed to sulfur mustard.



COVID-19 and Dentistry in 72 Questions: An Overview of the Literature
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Stéphane Derruau, Jérôme Bouchet, Ali Nassif, Alexandre Baudet, Kazutoyo Yasukawa, Sandrine Lorimier, Isabelle Prêcheur, Agnès Bloch-Zupan, Bernard Pellat, Hélène Chardin
J. Clin. Med. - 10 122518 - 4 - 2021
The outbreak of Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has significantly affected the dental care sector. Dental professionals are at high risk of being infected, and therefore transmitting SARS-CoV-2, due to the nature of their profession, with close proximity to the patient’s oropharyngeal and nasal regions and the use of aerosol-generating procedures. The aim of this article is to provide an update on different issues regarding SARS-CoV-2 and COVID-19 that may be relevant for dentists. Members of the French National College of Oral Biology Lecturers (“Collège National des EnseignantS en Biologie Orale”; CNESBO-COVID19 Task Force) answered seventy-two questions related to various topics, including epidemiology, virology, immunology, diagnosis and testing, SARS-CoV-2 transmission and oral cavity, COVID-19 clinical presentation, current treatment options, vaccine strategies, as well as infection prevention and control in dental practice. The questions were selected based on their relevance for dental practitioners. Authors independently extracted and gathered scientific data related to COVID-19, SARS-CoV-2 and the specific topics using scientific databases. With this review, the dental practitioners will have a general overview of the COVID-19 pandemic and its impact on their practice. View Full-Text



Molecularly imprinted polymers in miniaturized extraction and separation devices
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Thomas Bouvarel, Nathalie Delaunay, Valérie Pichon
First published - 44(8) 1727-1751 - doi.org/10.1002/jssc.202001223 - 2021
Molecularly imprinted polymers are highly selective and cost-effective materials, which have attracted significant interest in various areas such as sample pretreatment and chromatographic and electrophoretic separations. This review aims to present the state of the art concerning the miniaturization of these materials in order to meet the societal demand for reliable, fast, cheap, and solvent/sample saving analyses. The polymerization route specificities for the production of miniaturized molecularly imprinted polymers in capillaries or chip channels, such as open tubular, packed particles, magnetic nanoparticles, and in situ imprinted monoliths, are investigated. Their performances as selective supports in solid phase extraction and as stationary phases in electrochromatography and liquid chromatography, as well as their possible perspectives are discussed.




Protein-protected metal nanoclusters as diagnostic and therapeutic platforms for biomedical applications
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - ImanZare, Daniel M.Chevrier, Anna Cifuentes-Rius, NasrinMoradi, Yunlei Xianyu, SubhadipGhosh, LauraTrapiella-Alfonso, Ye Tian, Alireza Shourangiz-Haghighi, Saptarshi Mukherjee, Kelong Fan, Michael R.Hamblin
Materials Today - - doi.org/10.1016/j.mattod.2020.10.027 - 2021
The use of protein templates for the controlled synthesis of inorganic nanostructures has gained considerable attention in multidisciplinary fields, including electronics, optics, energy, sensing, and biomedicine, owing to their biocompatibility and structural programmability. The possible synergistic combination of protein scaffolds (and other biomolecules/biopolymers) with metal nanoclusters (MNCs) has created a new class of highly photoluminescent nanoprobes and nanodevices. For the first time, we will discuss the different types of protein templates used for MNC preparation with an emphasis on their optoelectronic properties for application. In particular, applications of protein-coated MNCs for chemosensing or biosensing of cancer biomarkers, neurotransmitters, pathogenic microorganisms, biomolecules, pharmaceutical compounds, and immunoassays are discussed in detail herein. Fluorescence-based and multimodal molecular imaging, both in vitro and in vivo based on functional proteins are also covered. Furthermore, we discuss the burgeoning growth of protein-coated MNCs (e.g., gold (Au) and silver (Ag) NCs) to develop synergistic nanotherapeutics with potential biomedical applications in chemotherapy, radiotherapy, photodynamic therapy (PDT), photothermal therapy (PTT), and antibacterial activity, as well as MNC-containing nanocomposites for enhanced bioimaging and controlled drug release. Overall, the proposed review highlights the recent progress, technical challenges and new horizons in this field, and summarizes our understanding of how MNC properties interact with the biological function of protein scaffolds to develop synergistic nanotherapeutics towards clinical translation.
Superparamagnetic iron oxide nanoparticles functionalized with a binary alkoxysilane array and poly(4-vinylpyridine) for magnetic targeting and pH-responsive release of doxorubicin
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Fernando Espinola-Portilla,ab Oracio Serrano-Torres, Gilberto F. Hurtado-López, Uriel Sierra, Anne Varenne, Fanny d’Orlyé, Laura Trapiella-Alfonso, Silvia Gutiérrez-Granados and Gonzalo Ramírez-García
New Journal of Chemistry - 45 3600-3609 - doi.org/10.1039/D0NJ05227B - 2021
Chemotherapeutic drugs cause harmful side effects in cancer patients due to their low specificity, calling for the development of more effective strategies for their dosage and administration. In this work, a smart drug nanocarrier was synthesized through the covalent functionalization of superparamagnetic iron oxide nanoparticles with a triblock copolymer, which includes a dual alkoxysilane array, ((3-aminopropyl)triethoxysilane and (trimethoxysilyl)propyl methacrylate), and the pH-responsive poly(4-vinylpyridine). The synthetic conditions were optimized through structural and physicochemical characterization after every functionalization step. Afterward, the systematic loading, capture, and release of the anticancer drug doxorubicin (Dox) were demonstrated at relevant pH values using a specially designed square wave voltammetry technique. This strategy revealed that the P4VP polymeric chains underwent reversible hydrophobic to hydrophilic transitions in acidic media, triggering a molecular distention driven by the induced intermolecular electro-repulsive forces. Thereafter, the Dox solution can easily penetrate the polymeric layer at pH values below 5.62 (the pKa of poly(4-vinylpyridine)), allowing a loading of 61.9 ± 5.4 mg g−1 in the nanocomplex. After deprotonation in a pH 7.4 buffer solution, the polymer chains underwent intermolecular interactions again, capturing the drug molecules. Subsequently, 93.5 ± 3.5% of the payload was released upon suspension of the nanocomplex in pH 4.0 media, which is significantly more acidic than healthy tissues. Since the magnetic properties of the MNPs were practically unaffected by the surface modification, this nanocomplex offers a versatile strategy for the pH-selective and magnetically-guided release of drugs.

Non-amplified impedimetric genosensor for quantification of miRNA-21 based on the use of reduced graphene oxide modified with chitosan
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Michael López Mujica Yuanyuan Zhang Fabiana Gutierrez Féthi Bédioui Gustavo Rivasa
Microchemical Journal - 160 105596 - https://doi.org/10.1016/j.microc.2020.105596 - 2021
We report here an impedimetric genosensor for the quantification of microRNA-21 using [Fe(CN)6]3−/4− as redox probe to transduce the hybridization event. The biosensing platform was built at a thiolated-gold electrode by covalent bond of reduced graphene oxide (RGO) modified with chitosan (CHIT) and further covalent attachment of the aminated DNA probe. GO was used to provide the carboxylic groups for the covalent attachment of CHIT and, once reduced, to improve the electroactivity of the resulting platform, while CHIT served as a bridge between the thiol and the aminated probe DNA. The proposed bioanalytical platform allows the label-free, non-amplified, simple and fast biosensing of microRNA-21, with a linear range between 1.0 × 10−12 M and 1.0 × 10−8 M, a sensitivity of (134 ± 4) ΩM−1 (r2 = 0.996), a detection limit of 300 fM, and a reproducibility of 5.9% for 1.0 × 10−12 M miRNA-21 and 2.2% for 1.0 × 10−9 M miRNA-21. The genosensor was successfully used for the quantification of microRNA-21 in enriched human blood serum, urine and saliva samples.


Corrosion analysis of AISI 430 stainless steel in the presence of Escherichia coli and Staphylococcus aureus
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - C.Guerra A.Ringuedé M.I.Azocar M.Walter C.Galarce F.Bedioui M.Cassir M.Sancy
Corrosion Science - 181 109204 - doi.org/10.1016/j.corsci.2020.109204 - 2021
AISI 430 stainless steel is an attractive material to be used in the healthcare industry, particularly as a sensor due to its low cost, corrosion resistance, as well as being Ni-free. AISI 430 was evaluated in an artificial sweat solution with the presence of Escherichia coli, and Staphylococcus aureus. Surface microbial analyses did not reveal colonization of bacteria on metallic surfaces, even when bacteria adhesion was investigated in a Müeller-Hinton solution. However, by electrochemical techniques, the AISI 430 surfaces demonstrated clear signs of corrosion mainly in a sterile medium after two weeks of exposure.



Liquid Crystal Coacervates Composed of Short Double-Stranded DNA and Cationic Peptides
Laboratoire Auto-Assemblage Moléculaire - Tommaso P. Fraccia and Tony Z. Jia
ACS Nano - 14, 11 15071–15082 - doi.org/10.1021/acsnano.0c05083 - 2020
Phase separation of nucleic acids and proteins is a ubiquitous phenomenon regulating subcellular compartment structure and function. While complex coacervation of flexible single-stranded nucleic acids is broadly investigated, coacervation of double-stranded DNA (dsDNA) is less studied because of its propensity to generate solid precipitates. Here, we reverse this perspective by showing that short dsDNA and poly-l-lysine coacervates can escape precipitation while displaying a surprisingly complex phase diagram, including the full set of liquid crystal (LC) mesophases observed to date in bulk dsDNA. Short dsDNA supramolecular aggregation and packing in the dense coacervate phase are the main parameters regulating the global LC-coacervate phase behavior. LC-coacervate structure was characterized upon variations in temperature and monovalent salt, DNA, and peptide concentrations, which allow continuous reversible transitions between all accessible phases. A deeper understanding of LC-coacervates can gain insights to decipher structures and phase transition mechanisms within biomolecular condensates, to design stimuli-responsive multiphase synthetic compartments with different degrees of order and to exploit self-assembly driven cooperative prebiotic evolution of nucleic acids and peptides.
Elasticity and Viscosity of DNA Liquid Crystals
Laboratoire Auto-Assemblage Moléculaire - Liana Lucchetti, Tommaso P. Fraccia, Giovanni Nava, Taras TurivTaras Turiv Advanced Materials and Liquid Crystal Institute, Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, United States More by Taras Turiv , Fabrizio
ACS Nano - 9, 7 1034–1039 - doi.org/10.1021/acsmacrolett.0c00394 - 2020
Concentrated solutions of blunt-ended DNA oligomer duplexes self-assemble in living polymers and order into lyotropic nematic liquid crystal phase. Using the optical torque provided by three distinct illumination geometries, we induce independent splay, twist, and bend deformations of the DNA nematic and measure the corresponding elastic coefficients K1, K2, and K3, and viscosities ηsplay, ηtwist, and ηbend. We find the viscoelasticity of the system to be remarkably soft, as the viscoelastic coefficients are smaller than in other lyotropic liquid crystals. We find K1 > K3 > K2, in agreement with the elasticity of the nematic phase of flexible polymers, and ηbend > ηsplay > ηtwist a behavior that is nonconventional in the context of chromonic, polymeric, and thermotropic liquid crystals, indicating a possible role of the weakness and reversibility of the DNA aggregates.
Liquid Crystal ordering of DNA Dickerson Dodecamer duplexes with different 5’- Phosphate terminations
LABORATOIRE AUTO-ASSEMBLAGE MOLÉCULAIRE - Marco Todisco Gregory P. Smith Tommaso Pietro Fraccia
Molecular Crystals and Liquid Crystals - 683(1) 69-80 - DOI: 10.1080/15421406.2019.1581706 - 2020
The onset of liquid crystal (LC) phases in concentrated aqueous solutions of DNA oligomers crucially depends on the end-to-end interaction between the DNA duplexes, which can be provided by the aromatic stacking of the terminal base-pairs or by the pairing of complementary dangling-ends. Here we investigated the LC behavior of three blunt-end 12-base-long DNA duplexes synthesized with hydroxyl, phosphate and triphosphate 5’-termini. We experimentally characterized the concentration-temperature phase diagrams and we quantitatively estimated the end-to-end stacking free energy, by comparing the empirical data with the predictions of coarse-grained linear aggregation models. The preservation of LC ordering, even in presence of the bulky and highly charged triphosphate group, indicates that attractive stacking interactions are still present and capable of induce linear aggregation of the DNA duplexes. This finding strengthens the potential role of chromonic like self-assembly for the prebiotic formation of linear polymeric nucleic acids.

635 publications.