The Effect of Glycerin Content in Sodium Alginate/Poly(vinyl alcohol)-Based Hydrogels for Wound Dressing Application

Abstract

The impact of different amounts of glycerin, which was used in the system of sodium alginate/poly(vinyl alcohol) (SA/PVA) hydrogel materials on the properties, such as gel fraction, swelling ability, degradation in simulated body fluids, morphological analysis, and elongation tests were presented. The study shows a significant decrease in the gel fraction from 80.5 ± 2.1% to 45.0 ± 1.2% with the increase of glycerin content. The T5 values of the tested hydrogels were varied and range from 88.7 °C to 161.5 °C. The presence of glycerin in the matrices significantly decreased the thermal resistance, which was especially visible by T10 changes (273.9 to 163.5 °C). The degradation tests indicate that most of the tested materials do not degrade throughout the incubation period and maintain a constant ion level after 7-day incubation. The swelling abilities in distilled water and phosphate buffer solution are approximately 200–300%. However, we noticed that these values decrease with the increase in glycerin content. All tested matrices are characterized by the maximum elongation rate at break in a range of 37.6–69.5%. The FT-IR analysis exhibits glycerin changes in hydrogel structures, which is associated with the cross-linking reaction. Additionally, cytotoxicity results indicate good adhesion properties and no toxicity towards normal human dermal fibroblasts.

Bio-Hybrid Hydrogels Incorporated into a System of Salicylic Acid-pH/Thermosensitive Nanocarriers Intended for Cutaneous Wound-Healing Processes

“…It was observed that the immersion of the studied matrices, incorporated into the smart nanocarrier-drug system and without the additive, leads to a systematic and gradual increase in the parameters in time in each fluid (Figure 3). The evaluation of the changes in ionic conductivity over time indicates the expected trends, similar to the results obtained by the authors in previously published research [36,39,43]. It was observed that the immersion of the studied matrices, incorporated into the smart nanocarrier-drug system and without the additive, leads to a systematic and gradual increase in the parameters in time in each fluid (Figure 3).…”

“…On the other hand, the type of carrier used shows no significant effect on the pH of the fluids. The authors observed similar trends in research on a sodium alginate/poly(vinyl alcohol)based matrix as a basis for studies on the incorporation of the active substance into the matrix presented in this paper [43]. The evaluation of the changes in ionic conductivity over time indicates the expected trends, similar to the results obtained by the authors in previously published research [36,39,43].…”

“…On the other hand, the type of carrier used shows no significant effect on the pH of the fluids. The authors observed similar trends in research on a sodium alginate/poly(vinyl alcohol)-based matrix as a basis for studies on the incorporation of the active substance into the matrix presented in this paper [43]. The most favorable environment for submerging/storing the tested bio-hybrid hydrogels is the SBF solution, in which only a slight decrease in the SR% parameter is observed with time.…”

“…After 3 h of stirring at room temperature, the drug-nanocarrier system was freeze-dried for 24 h [47,48]. The synthesis of the bio-hybrid hydrogels was mainly based on the previously described method [39,43]-by conventional chemical cross-linking using a 1% solution of ammonium persulfate as an initiator and poly(ethylene glycol) diacrylate (PEGDA, Mn = 700 g/mol) as a cross-linking agent. Briefly, the pH/thermosensitive nanocarrierssalicylic acid system was dispersed in 2% (w/v) of an aqueous solution of sodium alginate, using a magnetic stirrer at a constant speed.…”

“…This article is a continuation of the authors' previous research on developing the composition and desired features of a novel third-generation bio-hybrid dressing system [36,39,40,43]. So far, we have designed and tested hydrogels containing only natural active substances added to the base matrix before the cross-linking process.…”