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Cytosolic protein delivery remains elusive. The inability of most proteins to cross the cellular membrane is a huge hurdle. Here we explore the unique photothermal properties of gold nanorods (AuNRs) to trigger cytosolic delivery of proteins. Both partners, protein and AuNRs, are modified with a protease‐resistant cell‐penetrating peptide with nuclear targeting properties to induce internalization. Once internalized, spatiotemporal control of protein release is achieved by near‐infrared laser irradiation in the safe second biological window. Importantly, catalytic amounts of AuNRs are sufficient to trigger cytosolic protein delivery. To the best of our knowledge, this is the first time that AuNRs with their maximum of absorption in the second biological window are used to deliver proteins into the intracellular space. This strategy represents a powerful tool for the cytosolic delivery of virtually any class of protein. [ABSTRACT FROM AUTHOR]

To increase efficiencies of bifacial solar cells, emitter, back surface field (BSF), and metal patterns must be optimized. We study the influence of paste volume, through multiple prints, of two silver pastes on the contact formation at the rear side of n‐type passivated emitter and rear totally diffused (n‐PERT) solar cells with two BSF doping profiles. Differences in fingers' electrical properties were found between pastes. Contact resistivity shows a relative difference of 27.6%, partially explained by changes in the silver crystallites formation at the Ag/Si interface and in the crystallites' penetration depth. Variations in crystallites formation and penetration between pastes can reach 38.4% and 48.8%, respectively. Line resistance shows a difference between pastes, appearing as the main cause of an absolute efficiency difference of 2.9%. Fingers' structural and electrical properties are modified by increasing the paste volume. Microstructure analysis reveals that additional metallic printing does not only increase line cross sectional area but also increases the formation of silver crystallites, which can reach a relative increment of 23.9% between first and second prints. Further printing does not necessarily decrease contact resistivity, but reduces line resistance in up to 94.9%, which results in an absolute efficiency increase of 2.2%. In addition, the higher presence of silver oxide in the finger is related to a higher efficiency in the formation of silver crystallites. Finally, BSF doping has an influence in the open circuit voltage, short circuit current density, and contact resistivity, with differences that can reach 8.7 mV, 0.2 mA/cm2, and 6.1 mΩcm2, respectively, depending on paste and number of prints. [ABSTRACT FROM AUTHOR]

Chronic ethanol consumption leads to brain oxidative stress and neuroinflammation, conditions known to potentiate and perpetuate each other. Several studies have shown that neuroinflammation results in increases in chronic ethanol consumption. Recent reports showed that the intra-cerebroventricular administration of mesenchymal stem cells to rats consuming alcohol chronically markedly inhibited oxidative-stress, abolished neuroinflammation and greatly reduced chronic alcohol intake and post deprivation relapse-like alcohol intake. However, the intra-cerebroventricular administration of living cells is not suitable as a treatment of a chronic condition. The present study aimed at inhibiting ethanol intake by the non-invasive intranasal administration of human mesenchymal stem cell products: exosomes, microvesicles (40 to 150 nm) with marked antioxidant activity extruded from mesenchymal stem cells. The exosome membrane can fuse with the plasma membrane of cells in different tissues, thus delivering their content intracellularly. The study showed that the weekly intranasal administration of mesenchymal stem cell-derived exosomes to rats consuming alcohol chronically (1) inhibited their ethanol intake by 84 percent and blunted the relapse-like 'binge' drinking that follows an alcohol deprivation period and ethanol re-access. (2) Intranasally administered exosomes were found in the brain within 24 hours; (3) fully reversed both alcohol-induced hippocampal oxidative-stress, evidenced by a lower ratio of oxidized to reduced glutathione, and neuroinflammation, shown by a reduced astrocyte activation and microglial density; and (4) increased glutamate transporter GLT1 expression in nucleus accumbens, counteracting the inhibition of glutamate transporter activity, reportedly depressed under oxidative-stress conditions. Possible translational implications are envisaged. [ABSTRACT FROM AUTHOR]

This work determined the potency of hexyl‐ciprofloxacin molecules that reversibly interact with gold nanoparticles (AuNPs) passivated with 11‐mercaptoundecanoic acid (MUA) on Escherichia coli cells. For this, partition of modified antibiotic between different compartments of the gold colloid was determined using analytical techniques. First, concentration of hexyl‐ciprofloxacin was determined in the continuous phase of the colloid. Subsequently, the colloid was exposed to a volume of organic immiscible solvent and concentration of the transferred molecules was determined in the organic phase. Comparison of the amount of hexyl‐ciprofloxacin in each phase revealed that interaction between molecules and nanoparticles was reversible. Later, this work determined the potency of a population of hexyl‐ciprofloxacin molecules contained in a volume of the colloid, and the potency of other population of molecules that only interact with the continuous phase of the colloid. The absolute difference between these two values was proportional to the potency of a number of molecules that interact with the nanoparticles of the colloid. [ABSTRACT FROM AUTHOR]

Abstract: Gold nanoparticles (AuNPs) have unique properties, making them attractive for electronic and energy‐conversion devices and as (electro)catalysts for electrochemical sensors. In addition to the size and shape of AuNPs, the electrocatalytic properties of AuNP‐sensors are also determined by the stabilizing agent used in their synthesis. Here, AuNPs were synthesized with citrate, alginate and quercetin, obtaining spherical and negatively charged nanoparticles. The AuNPs were used to modify glassy carbon electrodes (AuNPs/GCE), which were characterized by scanning electron microscopy and electrochemical techniques. The AuNPs/GCE showed aggregates of different sizes and degrees of dispersion on the electrode surface depending on the stabilizing agent. The AuNP's aggregates affect the homogeneity of the film, the reproducibility of the electrodes and their response in buffer solution. Finally, to evaluate the electrocatalytic ability of the AuNPs/GCE, we studied the oxidation of two analytes with opposite charges: (1) sunset yellow (negative) and (2) hydrazine (positive). Compared with GCE, the AuNPs/GCE showed good electrocatalytic properties for hydrazine, increasing the current up to 50 % and shifting the potential by almost 400 mV, depending on the AuNP used. For the negatively charged analyte, the current decreased up to 50 % and no shift in potential was observed. Thus, the electrocatalytic properties of the AuNPs showed to be highly dependent on the nature of the analyte. [ABSTRACT FROM AUTHOR]

Presents a study on the fibrillogenesis process of the highly amyloidogenic self-associating amyloid β1-42 peptide by atomic force microscopy. Aim of the study; Findings of the study; Conclusion of the study.