Poly(Vinyl Alcohol) Cryogel Membranes Loaded with Resveratrol as Potential Active Wound Dressings

Abstract

Hydrogel wound dressings are highly effective in the therapy of wounds. Yet, most of them do not contain any active ingredient that could accelerate healing. The aim of this study was to prepare hydrophilic active dressings loaded with an anti-inflammatory compound - trans-resveratrol (RSV) of hydrophobic properties. A special attention was paid to select such a technological strategy that could both reduce the risk of irritation at the application site and ensure the homogeneity of the final hydrogel. RSV dissolved in Labrasol was combined with an aqueous sol of poly(vinyl) alcohol (PVA), containing propylene glycol (PG) as a plasticizer. This sol was transformed into a gel under six consecutive cycles of freezing (-80 °C) and thawing (RT). White, uniform and elastic membranes were successfully produced. Their critical features, namely microstructure, mechanical properties, water uptake and RSV release were studied using SEM, DSC, MRI, texture analyser and Franz-diffusion cells. The cryogels made of 8 % of PVA showed optimal tensile strength (0.22 MPa) and elasticity (0.082 MPa). The application of MRI enabled to elucidate mass transport related phenomena in this complex system at the molecular (detection of PG, confinement effects related to pore size) as well as at the macro level (swelling). The controlled release of RSV from membranes was observed for 48 h with mean dissolution time of 18 h and dissolution efficiency of 35 %. All in all, these cryogels could be considered as a promising new active wound dressings.

Superior Technique for the Production of Agarose Dressing Containing Sericin and Its Wound Healing Property

“…Comparing the three formulations (3A2S, 3A2S1G, 3A2S1P) of both preparation methods, the swelling ratio and protein release of all scaffolds were not significantly different ( Figure 1 and Figure 2 ). Glycerin and propylene glycol are highly soluble in water, so they were lost during the swelling and releasing studies [ 59 , 60 ], resulting in no significant difference in swelling ratio and protein release compared to the non-plasticizer formulation. These results were also confirmed by Guadarrama-Acevedo et al [ 61 ] who demonstrated that adding propylene glycol into polyvinylpyrrolidone did not affect the swelling ratio of the materials.…”

In Vitro Wound Dressing Stack Model as a First Step to Evaluate the Behavior of Dressing Materials in Wound Bed—An Assessment of Mass Transport Phenomena in Hydrogel Wound Dressings

“…In vitro testing of wound dressings using an MRI technique as such has been marginal so far, but published studies revealed the potential of these techniques. Previous papers by Górska et al have consistently emphasized the usefulness of MRI for the assessment of important features of hydrogel wound dressings [15,16]. On the example of asymmetric wound dressings obtained by the freezing-drying method, a quantitative assessment of various, spatiotemporal aspects of wound dressing membrane hydration has been presented.…”

“…Magnetic resonance imaging has also been used as one of the methods of characterization of hydrogel wound dressings obtained by the freezingthawing (F-T) technique. It has been possible to catch subtle changes inside the membrane during contact with bulk water, e.g., assessment of mass transport-related phenomena at the molecular-(detection of propylene glycol, confinement effects related to pore size) as well as at the macro-level (swelling) [16]. Nevertheless, these in vitro studies did not seem to have much in common with dissolution testing or with real application conditions.…”

“…The emphasis was put on interfacial phenomena at the dressing/substrate contact plane. To show the usefulness of the method, the assessment was made using samples of two previously described PVA-based hydrogels with and without the addition of Labrasol ® used as a surfactant and solubilizer in topical formulations [16]. Moreover, two different substrate environments were used, i.e., fetal bovine serum (medium related to in vivo situation) and propylene glycol as one of the possible acceptor fluids used for in vitro drug release tests [16].…”

“…To show the usefulness of the method, the assessment was made using samples of two previously described PVA-based hydrogels with and without the addition of Labrasol ® used as a surfactant and solubilizer in topical formulations [16]. Moreover, two different substrate environments were used, i.e., fetal bovine serum (medium related to in vivo situation) and propylene glycol as one of the possible acceptor fluids used for in vitro drug release tests [16]. According to our knowledge, the use of MRI to characterize wound dressings in contact with different environments and the analysis of the mechanisms occurring at the dressing-wound interface has not been reported as yet.…”