A Theoretical Model for Release Dynamics of an Antifungal Agent Covalently Bonded to the Chitosan

Abstract

The aim of the study was to create a mathematical model useful for monitoring the release of bioactive aldehydes covalently bonded to the chitosan by reversible imine linkage, considered as a polymer–drug system. For this purpose, two hydrogels were prepared by the acid condensation reaction of chitosan with the antifungal 2-formyl-phenyl-boronic acid and their particularities; influencing the release of the antifungal aldehyde by shifting the imination equilibrium to the reagents was considered, i.e., the supramolecular nature of the hydrogels was highlighted by polarized light microscopy, while scanning electron microscopy showed their microporous morphology. Furthermore, the in vitro fungicidal activity was investigated on two fungal strains and the in vitro release curves of the antifungal aldehyde triggered by the pH stimulus were drawn. The theoretical model was developed starting from the hypothesis that the imine-chitosan system, both structurally and functionally, can be assimilated, from a mathematical point of view, with a multifractal object, and its dynamics were analyzed in the framework of the Scale Relativity Theory. Thus, through Riccati-type gauges, two synchronous dynamics, one in the scale space, associated with the fungicidal activity, and the other in the usual space, associated with the antifungal aldehyde release, become operational. Their synchronicity, reducible to the isomorphism of two SL(2R)-type groups, implies, by means of its joint invariant functions, bioactive aldehyde compound release dynamics in the form of “kink–antikink pairs” dynamics of a multifractal type. Finally, the theoretical model was validated through the experimental data.

Biocompatible Chitosan-Based Hydrogels for Bioabsorbable Wound Dressings

“…Furthermore, the hydrogel showed an emission of blue light when illuminated with a UV lamp ( Figure 1 ), in line with the formation of supramolecular fluorophores [ 26 ]. This is in agreement with our previous studies, which proved that the hydrogelation of chitosan with monoaldehydes is possible due to an imination reaction followed by the self-assembly of the newly formed imine units into layered clusters playing the role of crosslinking nodes [ 26 , 30 ].…”

“…units self-ordered during the hydrogelation into a layered architecture pattern, similar to lyotropic liquid crystals (Figure 4) [29,30]. Furthermore, the hydrogel showed an emission of blue light when illuminated with a UV lamp (Figure 1), in line with the formation of supramolecular fluorophores [26].…”

“…POM images of the hydrogel showed bright birefringence with a banded texture identified for layered supramolecular architectures, proving that the new formed imine units self-ordered during the hydrogelation into a layered architecture pattern, similar to lyotropic liquid crystals ( Figure 4 ) [ 29 , 30 ]. Furthermore, the hydrogel showed an emission of blue light when illuminated with a UV lamp ( Figure 1 ), in line with the formation of supramolecular fluorophores [ 26 ].…”

Innovative Systems for the Delivery of Naturally Occurring Antimicrobial Volatiles in Active Food-Packaging Technologies for Fresh and Minimally Processed Produce: Stimuli-Responsive Materials

“…Most volatiles used in active packaging applications are aldehydes, ketones, esters, and alcohols, which are stabilized by pH-sensitive imine reversible bonds. Despite the common uses of imines in the design of stimuli-responsive structures for the incorporation and release of volatile molecules, few works have studied their volatile release mechanisms [ 118 ]. Figure 3 explains the volatile release mechanism concept.…”

Complex Behavior in the Dynamics of a Polymeric Biocomposite Material—“Liquid Wood”. Experimental and Theoretical Aspects

“…The hydrolysis process can also be used to obtain HPH (high pressure hydrolysis)-lignin with natural fibers in the form of injectable granules [ 16 ], in a presentation manner very similar to how injectable thermoplastics are commercially available. Even more, chitosan (a polysaccharide) seems to have good adhesive properties as well, again when being used in the context of wood processing [ 17 ], but it can also have medical uses [ 18 ].…”