Supramolecular gels by guanine and folic acid: from structural and mechanical properties to biotechnology applications

Guanosine and folic acid-based gels have great potential in developing advanced biomedical and biotechnological applications. Firstly, the study of the chemical-physical properties allows us to explore the structural organisation of gels composed of both guanosine derivatives and folic acid. These two buildings are involved in the spontaneous self-assembling process that ensures the formation of biomaterial termed hydrogels, organogels and ionogels, depending on the type of solvent used. The use of different types of biophysical techniques, such as Small and Wide-Angle X-ray Scattering (SAXS/WAXS), rheology, Fluorescence Recovery After Photobleaching (FRAP) based on the use of confocal microscopy, AFM and SEM based microscopy, infrared spectroscopy and others, offer a complete approach to have an in-depth structural analysis. Moreover, the structural investigation was fundamental in order to choose the best gel samples used for the different applications developed. In this regard, the studied applications belong to a wide range of scientific fields. G-hydrogel was found to be a potential biomaterial used as a 3D bioprinting scaffold for the growth of cells, but also to embed micro crystals proteins as an injectable system to support crystallography experiments (e.g. in a XFEL or synchrotron large-scale facilities). In addition, other uses of this hydrogel concern the formation of nano- and micro-structured gels, for instance for nanomedicine, but also water and surface remediation, for instance for the removal of heavy metals. This latter purpose was studied also for the case of hydrogel based on folic acid, demonstrating its great potential. The improvement of these results could be useful to reach new future milestones in the world of gels for biotechnological applications.