Benthosearcher: a machine learning based tool to ultra-fast, automatic characterization of vulnerable marine ecosystems

The degradation and impoverishment of the seabed that has been detected during last decades is the result of numerous variables, among which are uncontrolled exploitation of the seabed concerning its vulnerability, based on trawling gear. Intending to bring the situation under control, European fishing authorities have concluded a series of proposals to promote, define and defend Marine Vulnerable Ecosystems (VMEs), among which one of the most controversial and with the greatest social and economic impact is the veto of trawling in numerous fishing areas/grounds that currently are exploited by a large c number of vessels from many countries of the EU, which see their livelihood in danger. In the process of proposing an alternative that is attractive to both parts, we propose an automatic, real-time tool (BentoSearcher) based on artificial intelligence so that trawlers have will have the autonomy to decide whether or not to cast the net on the seabed in which the vessel is operating based on the data of benthic species detected in previous fishing hauls or trips that characterize and allow to identify vulnerable seabeds

New insights on the mechanism of polyethylenimine transfection and their implications on gene therapy and DNA vaccines

Polyethylenimine (PEI) has been demonstrated as an efficient DNA delivery vehicle both in vitro and in vivo. There is a consensus that PEI-DNA complexes enter the cells by endocytosis and escape from endosomes by the so-called “proton sponge” effect. However, little is known on how and where the polyplexes are de-complexed for DNA transcription and replication to occur inside the cell nucleus. To better understand this issue, we (i) tracked the cell internalization of PEI upon transfection to human epithelial cells and (ii) studied the interaction of PEI with phospholipidic layers mimicking nuclear membranes. Both the biological and physicochemical experiments provided evidence of a strong binding affinity between PEI and the lipidic bilayer. Firstly, confocal microscopy revealed that PEI alone could not penetrate the cell nucleus; instead, it arranged throughout the cytoplasm and formed a sort of aureole surrounding the nuclei periphery. Secondly, surface tension measurements, fluorescence dye leakage assays, and differential scanning calorimetry demonstrated that a combination of hydrophobic and electrostatic interactions between PEI and the phospholipidic monolayers/bilayers led to the formation of stable defects along the model membranes, allowing the intercalation of PEI through the monolayer/bilayer structure. Results are also supported by molecular dynamics simulation of the pore formation in PEI-lipidic bilayers. As discussed throughout the text, these results might shed light on a the mechanism in which the interaction between PEI and the nucleus membrane might play an active role on the DNA release: on the one hand, the PEI-membrane interaction is anticipated to facilitate the DNA disassembly from the polyplex by establishing a competition with DNA for the PEI binding and on the other hand, the forming defects are expected to serve as channels for the entrance of de-complexed DNA into the cell nucleus. A better understanding of the mechanism of transfection of cationic polymers opens paths to development of more efficiency vectors to improve gene therapy treatment and the new generation of DNA vaccinesThis work was supported by the Spanish "Ministerio de Ciencia, Innovación y Universidades" (Project PID2019–109517RB-I00)S

Functional gallic acid-based dendrimers as synthetic nanotools to remodel amyloid-β-42 into noncytotoxic forms

The self-assembly of amyloid-β (Aβ) generates cytotoxic oligomers linked to the onset and progression of Alzheimer’s disease (AD). As many fundamental molecular pathways that control Aβ aggregation are yet to be unraveled, an important strategy to control Aβ cytotoxicity is the development of bioactive synthetic nanotools capable of interacting with the heterogeneous ensemble of Aβ species and remodel them into noncytotoxic forms. Herein, the synthesis of nanosized, functional gallic acid (Ga)-based dendrimers with a precise number of Ga at their surface is described. It is shown that these Ga-terminated dendrimers interact by H-bonding with monomeric/oligomeric Aβ species at their Glu, Ala, and Asp residues, promoting their remodeling into noncytotoxic aggregates in a process controlled by the Ga units. The multivalent presentation of Ga on the dendrimer surface enhances their ability to interact with Aβ, inhibiting the primary and secondary nucleation of Aβ fibrillization and disrupting the Aβ preformed fibrils.The authors acknowledge the financial support from the EC (FORECAST-668983), “Programa Operacional Regional do Norte”, “Fundo Social Europeu”, Norte2020 TERM&SC, for the PhD grant NORTE-08-5369-FSE-000044, the Spanish Ministry of Science and Innovation (RTI2018-102212-B-I00), the Xunta de Galicia (ED431C 2018/30; Centro singular de investigación de Galicia accreditation 2019−2022, ED431G 2019/03), European Regional Development Fund-ERDF, and the Galician Supercomputing Centre (CESGA) and the MAT2016-80266-R of the Spanish Ministry of Science and Innovation

Heat capacity, density, surface tension, and contact angle for polyalphaolefins and ester lubricants

Thermophysical properties of lubricants are important to understand which ones are appropriated for the industrial conditions expected. Thermophysical properties of two different families of lubricants were analysed: polyalphaolefins (PAO6, PAO20, PAO32 and PAO40) and four ester-based lubricants. Specific heat capacity, density, surface tension, and contact angle were experimentally determined over a broad temperature range through methods such as μDSC, U-tube vibration, drop volume, and sessile drop method, respectively. A clear difference between the two families was observed due to their structure and composition, grouping by nature. Ester-based lubricants showed lower specific heat capacity but higher surface tension and density than polyalphaolefins. PAO6 clearly has the lowest density and surface tension and presents the highest specific heat capacity of all lubricants, and together with trimethylolpropane trioleate, TMPTO, presents the best wettability. Heat capacity values were used to test the validity of two predictive methodsThis work was supported by MINECO and the ERDF program through ENE2017-86425-C2-2-R project, and by Xunta de Galicia (ED431E 2018/08, and GRC ED431C 2020/10). M.A.C.S.M. acknowledges the Erasmus program for funding the researcher stay at the Santiago de Compostela University. M.J.G.G. thanks Xunta de Galicia (Spain) the support through a Postdoctoral Fellowship (ED481B-2019-015)S

On the structure and stability of novel cationic DPPC liposomes doped with gemini surfactants

A novel formulation of cationic liposomes was studied by mixing dipalmitoylphosphatidylcholine (DPPC) with tetradecyltrimethylammonium bromide gemini surfactants with different alkane spacer groups lengths attached to their ammonium head-groups. The physicochemical characterization of the cationic liposomes was obtained by combining experimental results from differential scanning microcalorimetry (DSC) with molecular dynamic simulations, in order to understand their structural configuration. An adapted Ising model was used to interpret the results in terms of cooperativity of the phase transitions. The gemini surfactants partition into the lipid bilayer of DPPC liposomes, and the induced changes in colloidal stability and phase transition were analyzed in detail. The DPPC liposomes became positively charged upon gemini surfactant partition, showing increased colloidal stability. Our results show significant differences in structural configuration between gemini surfactants with short and long spacer lengths. While gemini with shorter spacers allocate within the lipid bilayer with both headgroups in the same layer, geminis with longer spacers unexpectedly intercalate in the lipid membrane in a particular zig-zag configuration, with each headgroup located at a different side of the bilayer, altering the coupling degree parameters of the membrane’s phase transition. The extraordinary increase of colloidal stability of DPPC liposomes with gemini surfactants at very low molar ratio and the possibility to tune the physicochemical properties of the membrane by control de spacer length of the geminis opens new possibilities for cationic liposomal formulations with potential applications in vaccines, drug/gene delivery or biosensingThis work was supported by the Spanish Research Agency (AEI) under Project PID2019-109517RB-I00. ERDF funds are also acknowledged. Facilities provided by the Galician Supercomputing Centre (CESGA) are also acknowledgedS

Autoagregación de tensioactivos catiónicos gemini e a súa incorporación en formulacións de nanovesículas

Os liposomas son sistemas nanobiotecnolóxicos con un gran potencial para ser aplicados na administración de fármacos para o tratamento de diferentes tipos de enfermidades, na fase de diagnóstico e tamén na posible detección de enfermidades actuando como biosensores. O seu uso aumenta o índice terapéutico de fármacos, son seguros e moi biocompatibles. Varias propiedades destes vehículos, incluíndo o tamaño, carga superficial e a presenza de ligandos poden alterar o súa posible función. Polo tanto, os liposomas representan sistemas nanotransportadores atractivos para os fármacos e posúen un ampio potencial en diferentes ámbitos. En este proxecto proponse estudar novos sistemas liposómicos para aventurar novas aplicacións no ámbito biotecnolóxico. Para iso, plantexamos estudar sistema liposómicos compostos de fosfolípidos e dopalos con surfactantes catiónicos tipo gemini (GS). A idea fundamental radica en aportar propiedades diferentes (estabilidade, carga superficial, porosidade, permeabilidade, etc.) para aportar posibles aplicacións en diferentes ámbitos biotecnolóxicos. O estudo abordarase en tres bloques diferentes: (1) estudar o comportamento dos surfactantes gemini na superficie así como a termodinámica da autoagregación, (2) caracterizar os sistemas liposómicos coas distintas formulacións de distintos GS y (3) tratarase de encapsular diferentes tipos de medicamentos.2023-05-0

Benthosearcher: a machine learning based tool to ultra-fast, automatic characterization of vulnerable marine ecosystems

2 pages, 1 figure.-- MARTECH23, 10th Marine International Workshop on Marine Technology, 19-20 de Junio de 2023, Castellón de la PlanaThe degradation and impoverishment of the seabed that has been detected during last decades is the result of numerous variables, among which are uncontrolled exploitation of the seabed concerning its vulnerability, based on trawling gear. Intending to bring the situation under control, European fishing authorities have concluded a series of proposals to promote, define and defend Marine Vulnerable Ecosystems (VMEs), among which one of the most controversial and with the greatest social and economic impact is the veto of trawling in numerous fishing areas/grounds that currently are exploited by a large c number of vessels from many countries of the EU, which see their livelihood in danger. In the process of proposing an alternative that is attractive to both parts, we propose an automatic, real-time tool (BentoSearcher) based on artificial intelligence so that trawlers have will have the autonomy to decide whether or not to cast the net on the seabed in which the vessel is operating based on the data of benthic species detected in previous fishing hauls or trips that characterize and allow to identify vulnerable seabedsN

Classical and Nonclassical Nucleation Mechanisms of Insulin Crystals

13 pages, 12 figures.-- This article is licensed under CC-BY-NC-ND 4.0Although the Classical Nucleation Theory (CNT) is the most consensual theory to explain protein nucleation mechanisms, experimental observations during the shear-induced assays suggest that the CNT does not always describe the insulin nucleation process. This is the case at intermediate precipitant (ZnCl2) solution concentrations (2.3 mM) and high-temperature values (20 and 40 °C) as well as at low precipitant solution concentrations (1.6 mM) and low-temperature values (5 °C). In this work, crystallization events following the CNT registered at high precipitant solution concentrations (3.1 and 4.7 mM) are typically described by a Newtonian response. On the other hand, crystallization events following a nonclassical nucleation pathway seem to involve the formation of a metastable intermediate state before crystal formation and are described by a transition from Newtonian to shear-thinning responses. A dominant shear-thinning behavior (shear viscosity values ranging more than 6 orders of magnitude) is found during aggregation/agglomeration events. The rheological analysis is complemented with different characterization techniques (Dynamic Light Scattering, Energy-Dispersive Spectroscopy, Circular Dichroism, and Differential Scanning Calorimetry) to understand the insulin behavior in solution, especially during the occurrence of aggregation/agglomeration events. To the best of our knowledge, the current work is the first study describing nonclassical nucleation mechanisms during shear-induced crystallization experiments, which reveals the potential of the interdisciplinary approach herein described and opens a window for a clear understanding of protein nucleation mechanismsJ.F. acknowledges funding from CEFT under FCT/MCTES (PIDDAC) through a postdoctoral scholarship. This work was financially supported by HealthyWaters (NORTE-01-0145-FEDER-000069), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and LA/P/0045/2020 (ALiCE), UIDB/00532/2020, and UIDP/00532/2020 (CEFT), funded by national funds through FCT/MCTES (PIDDAC)Peer reviewe

Classical and non-classical nucleation mechanisms of insulin crystals supporting information

1 fileSupporting information for article https://doi.org/10.1021/acsomega.3c10052Peer reviewe