Hydrazone-modulated peptides for efficient gene transfection

Gene transfection continues to be a major challenge in chemistry, biology and materials sciences. New methodologies and recent breakthroughs have renewed the interest in the discovery and development of new tools for efficient gene transfection. Hydrazone formation between a cationic head and hydrophobic tails has emerged as one of the most promising techniques for nucleotide delivery. In this contribution, we have exploited hydrazone formation to modulate the transfection activity of a parent linear peptide in combination with a plasmid DNA cargo. This strategy allowed the straightforward preparation, under physiologically compatible conditions, of a discrete library of amphiphilic modulated penetrating peptides. Without the requirement of any isolation or purification steps, these modulated amphiphilic peptides were combined with a plasmid DNA and screened in transfection experiments of human HeLa cells. Three of these hydrazone-conjugated peptides were identified as excellent vectors for plasmid delivery with comparable, or even higher, efficiencies and lower toxicity than the commercial reagents employed in routine transfection assaysWe are thankful to Dr. Irene Lostalé-Seijo for cell culture assistance and discussions. We acknowledge funding from the Spanish Government MINECO: [CTQ2014-59646-R] and [CTQ2015-74621-JIN], the Xunta de Galicia (ED431G/09), the ERDF and the CESGA. R. G.-F. received a FCT Investigator Grant from Portugal (IF/01133/2015). J.M. received a Ramon y Cajal (RYC-2013-13784) and an ERC Starting Investigator Grant (DYNAP-677786)S

Peptide/Cas9 nanostructures for ribonucleoprotein cell membrane transport and gene edition

The discovery of RNA guided endonucleases has emerged as one of the most important tools for gene edition and biotechnology. The selectivity and simplicity of the CRISPR/Cas9 strategy allows the straightforward targeting and editing of particular loci in the cell genome without the requirement of protein engineering. However, the transfection of plasmids encoding the Cas9 and the guide RNA could lead to undesired permanent recombination and immunogenic responses. Therefore, the direct delivery of transient Cas9 ribonucleoprotein constitutes an advantageous strategy for gene edition and other potential therapeutic applications of the CRISPR/Cas9 system. The covalent fusion of Cas9 with penetrating peptides requires multiple incubation steps with the target cells to achieve efficient levels of gene edition. These and other recent reports suggested that covalent conjugation of the anionic Cas9 ribonucleoprotein to cationic peptides would be associated with a hindered nuclease activity due to undesired electrostatic interactions. We here report a supramolecular strategy for the direct delivery of Cas9 by an amphiphilic penetrating peptide that was prepared by a hydrazone bond formation between a cationic peptide scaffold and a hydrophobic aldehyde tail. The peptide/protein non-covalent nanoparticles performed with similar efficiency and less toxicity than one of the best methods described to date. To the best of our knowledge this report constitutes the first supramolecular strategy for the direct delivery of Cas9 using a penetrating peptide vehicle. The results reported here confirmed that peptide amphiphilic vectors can deliver Cas9 in a single incubation step, with good efficiency and low toxicity. This work will encourage the search and development of conceptually new synthetic systems for transitory endonucleases direct delivery.This work was partially supported by the Spanish Agencia Estatal de Investigación (AEI) [CTQ2014-59646-R], the Xunta de Galicia (ED431G/09 and 2016-AD031) and the ERDF. M. J. received a F. P. I. fellowship from MINECO. J. M. received a Ramón y Cajal (RYC-2013-13784), an ERC Starting Investigator Grant (DYNAP-677786) and a Young Investigator Grant from the Human Frontier Science Research Program (RGY0066/2017)S

Multipodal dynamic coordination involving cation-π interactions to control the structure of helical polymers

A precise tuning of the four possible states of a helix (P/M helical sense and stretched/compressed helical backbone) is attained by controlling the complexation between Li+ and a poly(phenylacetylene) that bears amide, ester and phenyl ring functionalities at the pendant group. Depending on the MeOH ratio that is present as a cosolvent, different coordination sites are involved in interactions leading to complexes I–III, each one with a characteristic structure (tri-, bi-, and unipodal) and an associated helical state. This dynamic coordination allows the selective modification of the helical sense or the stretching/compression backbone of a helical polymerWe thank Ministerio de Economía y Competitividad [CTQ2015-70519-P and CTQ2014-61470-EXP], Erasmus Mundus (M. Alzubi), Fundación Gil Dávila (S. Arias), Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2016–2019, GRC2014/040) and European Union (European Regional Development Fund –ERDF) for financial supportS

Cationic polymer mediated bacterial clustering: cell-adhesive properties of homo- and copolymers

New anti-infective materials are needed urgently as alternatives to conventional biocides. It has recently been established that polymer materials designed to bind to the surface of bacteria can induce the formation of cell clusters which enhance the expression of quorum sensing controlled phenotypes. These materials are relevant for anti-infective strategies as they have the potential to inhibit adhesion while at the same time modulating Quorum Sensing (QS) controlled virulence. Here we carefully evaluate the role that charge and catechol moieties in these polymers play on the binding. We investigate the ability of the cationic polymers poly(N-[3-(dimethylamino)propyl] methacrylamide) (pDMAPMAm, P1), poly(N-dopamine methacrylamide-co-N-[3-(dimethylamino)propyl] methacrylamide) (pDMAm-co-pDMAPMAm, P2) and p(3,4-dihydroxy-l-phenylalanine methacrylamide), p(l-DMAm, P3) to cluster a range of bacteria, such as Staphylococcus aureus (Gram-positive), Vibrio harveyi, Escherichia coli and Pseudomonas aeruginosa (Gram-negative) under conditions of varying pH (6, 7 and 8) and polymer concentration (0.1 and 0.5 mg/mL). We identify that clustering ability is strongly dependent on the balance between charge and hydrophobicity. Moreover, our results suggest that catechol moieties have a positive effect on adhesive properties, but only in the presence of cationic residues such as for P2. Overall, our results highlight the subtle interplay between dynamic natural surfaces and synthetic materials, as well as the need to consider synergistic structure–property relationship when designing antimicrobial polymers

Disruption of diphenylalanine assembly by a Boc-modified variant

Peptide-based biomaterials are key to the future of diagnostics and therapy, promoting applications such as tissue scaffolds and drug delivery vehicles. To realise the full potential of the peptide systems, control and optimisation of material properties are essential. Here we invesigated the co-assembly of the minimal amyloid motif peptide, diphenylalanine (FF), and its tert-butoxycarbonyl (Boc)-modified derivative. Using Atomic Force Microscopy, we demonstrated that the co-assembled fibers are less rigid and show a curvier morphology. We propose that the Boc-modification of FF disrupts the hydrogen bond packing of adjacent N-termini, as supported by Fourier transform infrared and fluorescence spectroscopic data. Such rationally modified co-assemblies offer chemical functionality for after-assembly modification and controllable surface properties for tissue engineering scaffolds, along with tunable morphological vs. mechanical properties

Rapid nano-gram scale screening method of micro-arrays to evaluate drug-polymer blends using high-throughput printing technology

A miniaturized, high-throughput assay was optimized to screen polymer-drug solid dispersions using a 2-D Ink-jet printer. By simply printing nanoliter amounts of polymer and drug solutions onto an inert surface, drug:polymer micro-dots of tunable composition were produced in an easily-addressable micro-array format. The amount of material printed for each dried spot ranged from 25 ng to 650 ng. These arrays were used to assess the stability of drug:polymer dispersions with respect to recrystallization, using polarized light microscopy. One array with a panel of 6 drugs formulated at different ratios with Poly (vinylpyrrolidone-vinyl acetate) copolymer (PVPVA) was developed to estimate a possible bulk (gram-scale) approximation threshold from the final printed nano amount of formulation. Another array was printed at a fixed final amount of material to establish a literature comparison of one drug formulated with different commercial polymers for validation. This new approach may offer significant efficiency in pharmaceutical formulation screening, with each experiment in the nano-micro-array format requiring from 3 up to 6 orders of magnitude lower amounts of sample than conventional screening methods

Por a no deixar empremta

Treballs de l'alumnat del Grau de Comunicació Audiovisual, Facultat de Biblioteconomia i Documentació, Universitat de Barcelona, Metanarratives - Grup6. Curs: 2017-2018, Tutor: Josep Rovira. // Directora: Berta Cotrina Domingo; Aj. Direcció: Iria Louzao Riádigos; Productor: Ignacio Encinas Vacas; Aj. Producció: Bárbara Prohens Coll; Guionista: Ángela Muñoz Delgado i Iria Louzao Riádigos; Dir. Fotografia: Berta Cotrina Domingo; Càmera: Eva Gómez Serrano i Ángela Muñoz Delgado; Il·luminador: Bárbara Prohens Coll; Direcció artística: Eva Gómez Serrano, Bárbara Prohens Coll, Ángela Muñoz Delgado, Berta Cotrina Domingo, Iria Louzao Riádigos i Ignacio Encinas Vacas; Direcció de so: Iria Louzao Riádigos; Muntatge: Berta Cotrina Domingo i Eva Gómez Serrano; Postproducció: Eva Gómez Serrano. Equip artístic: Irene Tínez.La protagonista es disposa a pintar sobre un llenç totalment en blanc, quan veu que els dibuixos no queden gravats l’envaeix la por i la frustració fins al punt d’acabar amb ella

Resistiré. El gran archivo de la música de los 60

Treballs Finals del Grau de Comunicació Audiovisual, Facultat d'Informació i Mitjans Audiovisuals, Universitat de Barcelona, Curs: 2019-2020, Tutor: Marquès Emo, Anna; Caso Sarabia, Carlota; Valero Merlos, Pedro; Manresa Casals, LaiaExpertos antropólogos hablan de los años 60 y 70 como una época de grandes conflictos políticos y culturales en España pero, también, de nuevas ideas y de apertura hacia el exterior. La música pop se convierte en un elemento comercial potente, y trae consigo una revolución en la moda, el cine, el arte y las costumbres. De pronto, Horacio se vio envuelto por la farándula, los aplausos y los focos de los escenarios frente a los que fotografiaba a artistas del calibre de Lola Flores, el Dúo Dinámico o Luis Aguilé. Pero, ser fotoperiodista musical fue ¿una elección o una obligación para Horacio? Mientras que durante el día Horacio trabajaba en el Banco Hispano Americano, por la noche recorría con su vespa las salas de fiesta más famosas de Barcelona. Con su cámara en mano Horacio no dormía para conseguir las mejores instantáneas de los artistas del momento. Los compromisos con las revistas musicales Fans, Discóbolo y Mosaico le obligaron a abandonar sus otros trabajos para centrarse por completo en la fotografía

Identification of novel ‘inks’ for 3D printing using high throughput screening: bioresorbable photocurable polymers for controlled drug delivery

A robust discovery methodology is presented to identify novel biomaterials suitable for 3D printing. Currently the application of Additive Manufacturing is limited by the availability of functional inks, especially in the area of biomaterials-this method tackles this problem for the first time allowing hundreds of formulations to be readily assessed. Several functional properties, including the release of an antidepressive drug (paroxetine), cytotoxicity and printability are screened for 253 new ink formulations in a high-throughput format as well as mechanical properties. The selected candidates with the desirable properties are successfully scaled up using 3D printing into a range of objects architectures. A full drug release study, degradability and tensile modulus experiments are presented on a simple architecture to validating the suitability of this methodology to identify printable inks for 3D printing devices with bespoke properties