PVA hydrogels loaded with a Brazilian propolis for burn wound healing applications

Abstract

PVA hydrogels offer many suitable characteristics for burn wound dressings. However, unmodified PVA gels do not act against infection. Propolis is a natural antimicrobial agent suitable for incorporation into PVA gels. PVA-propolis gels were produced by freeze-thawing method, and their microstructure, mechanical, and swelling properties (in standard PBS and a PBS-based solution with pH 4.0) were characterized. The propolis release profiles and the gel's antibacterial and cytotoxicity properties were also investigated. The presence of propolis in the gels interfered with the PVA crystallization profile and with the mechanical properties. All samples swelled at least 400% in both media. The propolis was mostly released to the media in the first day of immersion. PVA-propolis gels with concentrations of 15% propolis or more were active against the gram-positive bacterium Staphylococcus aureus, which is associated with initial colonization of the wound. All PVA-propolis samples acted as barriers to microbial penetration.

Absorbent polyvinyl alcohol–sodium carboxymethyl cellulose hydrogels for propolis delivery in wound healing applications

“…Propolis could be acting as a physical barrier to crystallization in a similar fashion to Heparin in PVA‐starch gels . In addition, a similar trend was previously observed in PVA‐propolis gels without CMC present.…”

“…Bands' displacement could mean the presence of intermolecular interactions between components . Similar results were found in PVA‐propolis samples . The displacement of the bands relative to the crystalline portion of PVA, at 1,143 cm −1 , ν (C O), and to the crystalline portion of NaCMC, at 1,378 cm −1 , δ (CH), could indicate the complete miscibility of PVA/NaCMC blends .…”

“…PVA gels with propolis as an antimicrobial have previously been developed by our research group. They exhibited appropriate mechanical properties and they were shown to inhibit S. aureus bacteria . The goal of the present work was to prepare PVA‐NaCMC blends incorporating propolis to be studied as propolis carriers in burns treatment.…”

Antimicrobial and cytotoxic activity of red propolis: an alert for its safe use

“…In general terms, propolis is considered a nontoxic substance that does not produce irritation in most people when applied topically (Shruthi and Suma 2012); however, new cytotoxic studies in human keratinocytes suggest the opposite (Oliveira et al 2015). This new type of propolis (red propolis) seems to have more promising therapeutic properties than the other types of propolis.…”

Properties of PVA Hydrogel Wound‐Care Dressings Containing UK Propolis

“…Propolis has recently been loaded into hydrogels designed for wound‐care with success, e.g. Brazilian propolis was previously incorporated in PVA hydrogels; biocelluloses membranes loaded with propolis were effective against S. aureus species; latex membranes loaded with propolis were active against C. albicans species . The goal of the present work was to incorporate a propolis from the United Kingdom into PVA hydrogels and to evaluate the gels microstructural, mechanical and swelling properties.…”