Small-angle neutron scattering and Molecular Dynamics structural study of gelling DNA nanostars

DNA oligomers with properly designed sequences self-assemble into well defined constructs. Here, we exploit this methodology to produce bulk quantities of tetravalent DNA nanostars (each one composed by 196 nucleotides) and to explore the structural signatures of their aggregation process. We report small-angle neutron scattering experiments focused on the evaluation of both the form factor and the temperature evolution of the scattered intensity at a nano star concentration where the system forms a tetravalent equilibrium gel. We also perform molecular dynamics simulations of one isolated tetramer to evaluate the form factor theoretically, without resorting to any approximate shape. The numerical form factor is found to be in very good agreement with the experimental one. Simulations predict an essentially temperature independent form factor, offering the possibility to extract the effective structure factor and its evolution during the equilibrium gelation.Comment: 9 pages, 5 figure

Correction to: Adolescent self‑administration of the synthetic cannabinoid receptor agonist JWH‑018 induces neurobiological and behavioral alterations in adult male mice

The authors inadvertently excluded Dr. Pagano Zottola from the list of authors, the journal Psychopharmacology has no responsibility for the omission. All authors agree to correct the list of authors as follows: Giulia Margiani#,1, Maria Paola Castelli #,1, Nicholas Pintori1, Roberto Frau1,2, Maria Grazia Ennas1, Antonio C. Pagano Zottola4,5,7, Valeria Orrù3, Valentina Serra3, Edoardo Fiorillo3, Paola Fadda1,6, Giovanni Marsicano4,5,Maria Antonietta De Luca1 4 INSERM, U1215 NeuroCentre Magendie, Bordeaux, France 5 University of Bordeaux, Bordeaux, France 7 Institut de Biochimie et Génétique Cellulaires, UMR 5095, Bordeaux France The original article has been corrected. © 2023 Springer-Verlag GmbH Germany, part of Springer Nature

Risk factors for oral mucositis in paediatric oncology patients receiving alkylant chemotherapy

BACKGROUND: We describe the risk indicators for oral mucositis (OM) in paediatric oncology patients hospitalised in the Institut Gustave Roussy (Villejuif-Paris) and treated with alkylant chemotherapy with autologous peripheral blood progenitor cells. METHODS: The sample was selected using PIGAS software. Three groups of subjects received different chemotherapy regimens: A. Melphalan, B. Busulfan and C. other alkylant protocols. The degree of mucositis was recorded by CTC version 2.0 (Common Toxicity Criteria). Descriptive statistics were performed. The association between mucositis and risk indicator variables was tested using a χ(2 )test. The association between case status and covariates was tested using unconditional logistic regression analysis. RESULTS: Of the 337 children enrolled, 241 showed mucositis (group 1) and 96 did not show mucositis (group 2) during alkylant chemotherapy. There was a higher prevalence of male patients in both groups. The three different chemotherapy regimen groups are correlated with the appearance of oral mucositis (χ(2 )= 22.42, p < 0.01). Weight loss was higher in group 1 (χ(2 )= 6.31, p = 0.01). The duration of aplasia was lower in the Busulfan protocol (7.5 days) than in the Melphalan group (9.3 days) or the other regimens (8.6 days). The use of Bufulfan(® )was directly associated with case status (presence of oral mucositis): odds ratio [OR] = 2.1 and confidence interval [95%CI] = 1.3–3.0. Also, occurrences of germinal tumours and secondary bacterial infections were directly linked with case status: [OR] = 1.4 and 1.8, confidence interval [95%CI] = 1.2 – 1.7 and 1.1 – 2.5, respectively. CONCLUSION: The presence of OM was associated with the three different chemotherapy regimens considered; in particularly patients treated with Busulfan had the highest prevalence

Structure of Bolaamphiphile Sophorolipid Micelles Characterized with SAXS, SANS, and MD Simulations

International audienceThe micellar structure of sophorolipids, a glycolipid bolaamphiphile, is analyzed using a combination of small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), and molecular dynamics (MD) simulations. Numerical modeling of SAXS curves shows that micellar morphology in the noncharged system (pH< 5) is made of prolate ellipsoids of revolution with core–shell morphology. Opposed to most surfactant systems, the hydrophilic shell has a nonhomogeneous distribution of matter: the shell thickness in the axial direction of the ellipsoid is found to be practically zero, while it measures about 12 Å at its cross-section, thus forming a “coffee bean”-like shape. The use of a contrast-matching SANS experiment shows that the hydrophobic component of sophorolipids is actually distributed in a narrow spheroidal region in the micellar core. These data seem to indicate a complex distribution of sophorolipids within the micelle, divided into at least three domains: a pure hydrophobic core, a hydrophilic shell, and a region of less defined composition in the axial direction of the ellipsoid. To account for these results, we make the hypothesis that sophorolipid molecules acquire various configurations within the micelle including bent and linear, crossing the micellar core. These results are confirmed by MD simulations which do show the presence of multiple sophorolipid configurations when passing from spherical to ellipsoidal aggregates. Finally, we also used Rb+ and Sr2+ counterions in combination with anomalous SAXS experiments to probe the distribution of the COO– group of sophorolipids upon small pH increase (5 < pH < 7), where repulsive intermicellar interactions become important. The poor ASAXS signal shows that the COO– groups are rather diffused in the broad hydrophilic shell rather than at the outer micellar/water interface

Green Nanovectors for Phytodrug Delivery: In-Depth Structural and Morphological Characterization

Lipid-based soft nanovectors are widely used for delivery purposes in many fields of applications. Although it is generally considered a class of molecules with superior biocompatibility, in recent times researchers have expressed concerns with regards to the sustainability of preparation procedures. In particular, when large-scale production is involved, as in the case of agro-nanotechnology applications, this becomes a most pressing issue. Recently, we proposed novel green nanoformulations for the delivery of phytohormones (i.e., indole-3-butyric acid and 1-naphthaleneacetic acid) to Olea europaea L., obtained from agricultural waste derived from the plant itself, which yielded promising results, especially when engineered by addition of pure phospholipids in small amounts (10% w/w). Here we have performed an advanced analysis of high-resolution structural data from X-ray and neutron scattering (SAXS/SANS) and cryo-transmission electron microscopy (cryo-TEM). The results obtained from these combined techniques were complementary and fully consistent, evidencing the fundamental role of the employed adjuvant phospholipid in dictating the structural arrangement