Guanosine‐5′‐Monophosphate Polyamine Hybrid Hydrogels: Enhanced Gel Strength Probed by z‐Spectroscopy

Abstract

The self-assembling tendencies of guanosine-5'-monophosphate (GMP) can be drastically increased using polyamines, with potential applications in the production of biocompatible smart materials, as well as for the design of antitumor drugs based on G-quadruplex stabilization. Results from scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), rheology, and nuclear magnetic resonance (NMR) z-spectroscopy studies are presented.

Hybrid GMP–polyamine hydrogels as new biocompatible materials for drug encapsulation

“…Furthermore, different polyamines produce different results depending on their charge and on the arrangement of the ammonium sites along their structure. 18 Therefore, besides temperature, there are three main factors to consider in this study: i) GMP concentration, ii) pH, since it establishes the protonation state of GMP and polyamines, and iii) the molar GMP:polyamine ratio needed to produce the hydrogels. To address the latter point, we tried different molar ratios for each GMP-polyamine system keeping the GMP concentration at 30 mM.…”

“…In previous work we adopted a strategy based on the use of protonated polyamines to induce GMP gelation. 18 Polyamines have a remarkable affinity for phosphate groups 16c,19 that depends not only on the charge but also on the charge distribution in the molecule. Moreover, even though polyamines might be toxic, there are a number of them that exists within cells in large amounts playing key biological roles.…”

Metal ions confinement defines the architecture of G-quartet, G-quadruplex fibrils and their assembly into nematic tactoids

“…WAXS intensity profiles on the freezedried samples show a characteristic peak around 3.3 Å (Fig. 2, Table 1), which corresponds to the π-π stacking distance of G-quartets (50)(51)(52). Moreover, the freeze-dried fibrils show a columnar oblique packing of the cylinders with lattice parameters of ca.…”

All-small-molecule supramolecular hydrogels assembled from guanosine 5′-monophosphate disodium salt and tobramycin for the treatment of bacterial keratitis

“…Guanosine-5′-monophosphate, the basic component of RNA, are well-known to form guanosine-quartets (G-quartets) with alkali metal ions via hydrogen bonding and coordination, and further assembled into G-quadruplexes nanofibers through π-π stacking [ 18 , 35 , 36 ]. Noted that there are multiple negative charged phosphates along the assembled nanofibers [ 37 ], we proposed a supramolecular hydrogel fabricated via the electrostatic interactions between guanosine 5′-monophosphate disodium salt (GMP) and tobramycin (TOB), which is the first-line antibacterial drug in the clinical treatment of bacterial keratitis. TOB is a kind of aminoglycoside antibiotic bearing multiple primary amine groups in the structure [ 28 , [38] , [39] , [40] , [41] ], the electrostatic interaction between the primary amine groups of TOB and negatively charged phosphates on assembled GMP nanofibers will facilitate the formation of a supramolecular GMP/TOB gel (GT Gel).…”