Synthesis and characterization of supramolecular hydrogels using ATP and GMP as molecular building blocks

Abstract

Molecular self-assembly is the fundamental basis of supramolecular chemistry. Supramolecular chemistry, also known as “chemistry beyond the molecule”, deals with the study of the formation of ordered, directional, tunable, reversible molecular aggregates or organizations by noncovalent interactions (pi stacking interactions, van der Waals, H-bonding metal coordination, solvophobic, electrostatic, etc.). One of the important applications of supramolecular self assembly is the synthesis of semi-solid colloidal “hydrogel”. Hydrogels are soft in nature which resembles biological tissues. They have ability to absorb a large amount of solvent in their matrix, making them attractive biomaterials for various applications in developing targeted drug delivery system, tissue engineering, wound healing, catalysis, etc. The three-dimensional architecture of hydrogel is based on structural properties of gelator molecules which form cross-linked networks through above mentioned weak non-covalent interactions that can hold a large volume of water. The native biomolecules such as peptides, nucleic acids, and carbohydrates are also used as an exclusive class of small gelator molecules. Presence of various noncovalent interaction sites makes the nucleotides a naturally occurring hydrogelators. The stimuli responsiveness and biocompatibility of the resultant supramolecular self-assembled hydrogels can be harnessed towards fascinating functional materials taking advantage of the inherent characteristics. Herein, we report the synthesis of a novel supramolecular self-assembled hydrogel by coordinating nucleotide ATP with GMP. The ATP-GMP hydrogel was formed by simple mixing in the molar ratio of 1:1. The hydrogel is expected to exhibit various fascinating properties such as synthetic reversibility, self-healing, self-supporting, injectable, bio mimicking, stimuli responsiveness, ion-conducting, and significant water holding ability that might influence a wide range of applications in material as we as biomedical sciences. This thesis covers the following topics: introduction and background, experimental section, and results and discussions.