Hidrogeles supramoleculares peptídicos para la obtención de materiales multicomponente con aplicaciones tecnológicas

Abstract

Supramolecular hydrogels formed by short peptides have garnered increasing interest in the scientific community over the past 20 years. This is primarily due to their composition of molecules found in living organisms, which grants them significant biocompatibility and biodegradability, making them suitable for therapeutic and biomedical applications. However, one of their most compelling characteristics is their chemical versatility. By selecting different amino acids, the properties of these hydrogels can be adapted, incorporating desired features into the peptide backbone. These properties can range from hydrophobic interactions (aromatic amino acids) to entirely hydrophilic ones (polar amino acids), as well as the introduction of anchoring groups for various components, such as metal nanoparticles (methionine or cysteine). This wide range of adaptability has expanded their potential applications to less intuitive fields, such as molecular electronics. Accordingly, this work harnesses the versatility of these hydrogels to develop new multi-component materials, further broadening their application scope. Chapter 3 explores the use of peptide hydrogels in coating carbon nanotubes and graphene nanosheets to study the properties of chirality-induced spin selectivity (CISS) effect in these systems. Promising results were obtained for the application of these hybrid materials in the field of spintronics. Chapter 4 investigates the potential of using these hydrogels as templates for the growth of inorganic crystals, specifically metal-organic frameworks (MOFs), with the aim of developing new families of MOFs integrated with biomaterials, or bio-MOFs. As a result, two new families of bio-MOFs were developed, one based on ZIF-8 and the other on MOF-808. Furthermore, as a proof of concept, the latter was used for the removal of phosphates from aqueous environments, where they can cause severe environmental issues such as eutrophication. The material was also applied in the degradation of a highly toxic phosphorus-based pesticide, methyl paraoxon, transforming it into two less harmful compounds, 4- nitrophenol and dimethyl phosphate, with higher efficiency than its counterpart without biopolymer. Chapter 5 utilizes the capacity of these hydrogels to coordinate with various metal cations, employing them as templates for the formation of plasmonic silver and gold nanoparticles. A green chemistry protocol was followed, where no external reducing agents were used; instead, the hydrogel acted as both a protective and reducing agent for the nanoparticles. A composite material of multiple gelators was also developed, achieving greater biocompatibility. These hydrogels have demonstrated strong antimicrobial activity, showing efficacy against Gram-positive and Gram-negative bacteria, as well as fungi. Additionally, they were found to be effective against polymicrobial biofilms. In vivo systems also showed promising results in wound healing and the treatment of infections caused by Staphylococcus aureus. Finally, Chapter 6 employs some of the hybrid hydrogels developed in the previous chapters as growth media for composite protein crystals. A solid-state material was achieved for studying the CISS effect by obtaining lysozyme crystals in hydrogels doped with carbon nanotubes. Lysozyme crystals doped with silver and gold plasmonic nanoparticles were also developed within a hydrogel designed to protect the nanoparticles during protein crystal growth, paving the way for the use of these systems in broad-spectrum antibacterial applications. Additionally, size-controlled protein crystals were obtained for doping with palladium and their use as catalysts in bioorthogonal chemistry, showing promising results for potential in vivo implant applications.