Poly(vinyl alcohol)/chitosan hydrogels with electrochemically synthesized silver nanoparticles for wound dressing applications

Katarina Nešović,Aleksandra Perić-Grujić,Ana Janković,Maja Vukašinović-Sekulić,Vesna Kojić,Kyong Yop Rhee,Vesna Mišković-Stanković,Tamara Radetić

doi:10.5599/jese.732

Abstract

Polymer-based hydrogel materials are excellent candidates for new-generation wound dressings with improved properties, such as high sorption ability, good mechanical properties and low adhesiveness. Cross-linked hydrogel matrices also serve as excellent carriers for controlled release of antibacterial agents, such as silver nanoparticles (AgNPs), which are preferred over conventional antibiotics due to low propensity to induce bacterial resistance. In this work, we aim to produce novel silver/poly(vinyl alcohol)/chitosan (Ag/PVA/CHI) hydrogels for wound dressing applications. The electrochemical AgNPs synthesis provided facile and green method for the reduction of Ag+ ions inside the hydrogel matrices, without the need to use toxic chemical reducing agents. The formation of AgNPs was confirmed using UV-visible spectroscopy, scanning and transmission electron microscopy. Release kinetics was investigated in modified phosphate buffer solution at 37 °C to mimic physiological conditions. Release profiles indicated “burst release” behavior, which is beneficial for wound dressing applications. The antibacterial activity was evaluated against Staphylococcus aureus and Escherichia coli strains using disc-diffusion test, and non-toxicity of hydrogels was proved by dye-exclusion test. The obtained results confirmed strong potential of Ag/PVA/CHI hydrogels for biomedical applications.

Highlights

Wound dressing materials are a major focus of biomedical and materials science research
poly(vinyl alcohol) (PVA) polymer has been long known for its property to form elastic and wellstructured hydrogel networks through freezing-thawing technique [15,23,28,29,30], that can be tailored by modifying the duration, temperature, and the number of cycles to control the hydrogel properties [28]
We have synthesized poly(vinyl alcohol) and chitosan polymer blend hydrogels aimed for wound dressing materials

Summary

Introduction

Wound dressing materials are a major focus of biomedical and materials science research. Several polymers (both natural-origin and synthetic) have emerged as acceptable candidates that satisfy this most important property. Among those are biocompatible and often biodegradable polymers such as alginate, chitosan (CHI), poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), cellulose, etc. Apart from biocompatibility, hydrogel-based wound dressings must satisfy several other stringent requirements, e.g. sterility, non-toxicity/non-inflammatory characteristics, permeability, low adhesiveness, high sorption, moisture and temperature regulation, mechanical integrity [12]. Freezing-thawing is a green and simple method for obtaining hydrogels with high gelation degrees and has been widely applied for preparing poly(vinyl alcohol)-based hydrogels [14,15,16], it was proved ineffective for other polymer types, such as PVP [14]

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