Antibacterial activity of chitosan/collagen membranes containing red propolis extract

In this study we developed a mucoadhesive polymeric membrane wound dressing incorporating red propolis extract (HERP). Membranes were made using a casting method employing collagen, chitosan, polyethylene glycol (15, 20, and 30v%), and hydroethanolic extract of EtOH-H₂O 70v% - 30v% (v/v) of HERP (0.5, 1.0, and 1.5%). Membranes were extensively characterized to assess the thickness, pH, morphology using Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), mechanical properties, swelling, in vitro mucoadhesion, cytotoxicity, and minimum inhibitory concentration (MIC). Assessment of the thickness and mechanical properties of the membranes containing HERP revealed that the most significant thickness obtained was 40.7 μm; thermal analysis suggests suggesting the hydrogen bonds between hydroxyl groups of isoflavones and the free amine present in the region of chitosan. Cell viability decreased as the amount of HERP increased. Finally, the MICs were 7.8 and 1.9 μg.mL^-1 for Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, respectively. These results were suggesting that the 0.5 % HERP membrane has the potential for future studies for wound application.