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

Abstract

<p class="PaperAbstract">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<sup>+</sup> 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.</p>

Silver/poly(vinyl alcohol)/graphene hydrogels for wound dressing applications: Understanding the mechanism of silver, antibacterial agent release

“…As bulk deposition of metallic Ag layer is undesirable at the cathode surface, the polarity of electrodes is reversed after half of the implementation time, which causes anodic dissolution of bulk Ag layer. Moreover, the hydrogen that is intensively produced at the cathode due to the electrolysis of water, can permeate through the hydrogel and reduce Ag + ions to Ag 0 directly inside the hydrogel matrix, [ 39,40,69 ] causing the formation of nucleation centers, which can further grow to form AgNPs. The importance of the polymer hydrogel matrix is that it represents a stabilization agent, which favors the formation of AgNPs, limiting their agglomeration and reduces the formation of larger particles.…”

A comprehensive review of the polymer‐based hydrogels with electrochemically synthesized silver nanoparticles for wound dressing applications

“…The first method involves the AgNPs synthesis in the colloid solution of polymers, with subsequent preparation of the desired form (film, hydrogel, or other), [26][27][28][29]125,126 whereas in the second route hydrogels are prepared first, then swollen in the solution of Ag + precursor, and subsequently subjected to electrical current to obtain AgNPs synthesized in situ. [30][31][32][33][34][35][36]127 Both methods will be briefly explained in the following subsections.…”

“…Among the most widely-used models are early-time approximation (ETA), 145 Korsmeyer-Peppas, 150,151 Kopcha, 152 and Makoid-Banakar, 144,153 as well as by the well-known kinetic models (zero-, first-, second-order, etc.) 127,154 that can help elucidate the kinetics of release. An overview of the most frequently-used models of silver release from different polymer carriers is provided in Table 5.…”

“…Entire range [34][35][36]144,153] Zero-order c Ag = c Ag, 0 − k 0 Á t Depending on the kinetics [127] First-order…”

Plasmonic nanomaterials with responsive polymer hydrogels for sensing and actuation

“…The required hydrophilicity of the repeat units in the polymer chain is provided by functional moieties with high polarity, such as hydroxyl, amino, carboxyl, ionic, or even zwitterionic groups. 38 The polymers may be derived from hydrophilic monomers based on synthetic sources (like acrylates, 39 acrylamides, 40 2-oxazolines, 41 and sulfo- or carboxy-betaines 42 ), or originating from natural sources (such as dextrans, 43 alginates, 44 polypeptides, 45 proteins, 46 hyaluronic acid, 47 and chitosan 48 ). The water-swollen, soft materials with high chemical versatility, which hydrogels represent, can mimic living tissue, 49 be easily integrated into biological systems, 50 and serve as a binding matrix material in bioanalytical application technologies as well as artificial muscles in soft robotics.…”