Novel composite zinc-alginate hydrogels with activated charcoal aimed for potential applications in multifunctional primary wound dressings

Abstract

Composites based on Zn-alginate hydrogels in the form of beads were produced by extrusion of a suspension containing 0.5 % w/w of alginate and 20 % w/w of activated charcoal (AC) with the intent to simultaneously release two active agents, Zn2+ and AC particles, in a physiological-like environment. The obtained composite beads were analyzed by FE-SEM and characterized regarding textural parameters, as well as Zn2+ and AC release kinetics in the physiological saline solution. Zn2+ions were quickly released reaching the equilibrium concentration within the first hour in the contrary to the release of AC particles, which was described by internal diffusion with the apparent diffusion coefficient of approximately 10-13 m2 s-1. Potential functionality of the obtained beads was evaluated regarding antibacterial activity in suspensions of the standard bacterial strain Escherichia coli 25922. The observed strong bactericidal effects were related to the quick release of Zn2+ that was not affected by AC. Thus, taking into account results of this study, as well as high sorption capacity of alginate hydrogel, efficiency of AC to adsorb malodor and tissue degradation products and positive effects of Zn2+ on wound healing, the obtained composites have shown promising potentials for applications as multifunctional wound dressings.