Browsing by Author "Grijalvo, Santiago"

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    Expanding the limits of amide-triazole isosteric substitution in bisamide-based physical gels
    (2019) Tautz, Markus; Torras, Juan; Grijalvo, Santiago; Eritja, Ramón; Saldias, César; Alemán, Carlos; Díaz Díaz, David
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    Polymer topology-controlled self-healing properties of polyelectrolyte hydrogels based on DABCO-containing aromatic ionenes
    (2019) Haering, Marleen; Grijalvo, Santiago; Haldar, Debasish; Saldias, Cesar; Diaz Diaz, David
    DABCO-containing polymers based on a disubstituted phenylene dibenzamide core constitute versatile gelators enabling the formation of hydrogels for different applications. In this work we have found that the polymer topology, controlled by the disubstitution pattern of the aromatic core, plays a crucial role on the self-healing properties of the corresponding hydrogels. Specifically, the ortho-isomer showed very superior shape persistent, self-standing and self-healing properties compared to its meta - and pare-analogues. Interestingly, the healing process occurred without the need of involving oppositely charged species.
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    Sulfonamide as amide isostere for fine-tuning the gelation properties of physical gels
    (2020) Alegre-Requena, Juan, V; Grijalvo, Santiago; Sampedro, Diego; Mayr, Judith; Saldias, Cesar; Juan Marrero-Tellado, Jose; Eritja, Ramon; Herrera, Raquel P.; Diaz Diaz, David
    (S)-2-Stearamidopentanedioic acid (C-18-Glu) is a known LMW gelator that forms supramolecular gels in a variety of solvents. In this work, we have carried out the isosteric substitution of the amide group by a sulfonamide moiety yielding the new isosteric gelator (S)-2-(octadecylsulfonamido)pentanedioic acid (Sulfo-Glu). The gelation ability and the key properties of the corresponding gels were compared in terms of gelation concentration, gel-to-sol transition temperature, mechanical properties, morphology, and gelation kinetics in several organic solvents and water. This comparison was also extended to (S)-2-(4-hexadecyl-1H-1,2,3-triazol-4-yl)pentanedioic acid (Click-Glu), which also constitutes an isostere of C-18-Glu. The stabilizing interactions were explored through computational calculations. In general, Sulfo-Glu enabled the formation of non-toxic gels at lower concentrations, faster, and with higher thermal-mechanical stabilities than those obtained with the other isosteres in most solvents. Furthermore, the amide-sulfonamide isosteric substitution also influenced the morphology of the gel networks as well as the release rate of an embedded antibiotic (vancomycin) leading to antibacterial activity in vitro against Staphylococcus aureus.