Composite Biopolymer-Based Wafer Dressings Loaded with Microbial Biosurfactants for Potential Application in Chronic Wounds

Abstract

In this study two bioactive polysaccharide polymers kappa-carrageenan (CARR) and sodium alginate (SA) incorporated with microbial biosurfactants (BSs) were formulated as medicated wafer dressings for potential application in chronic wounds. Wafers were loaded with BSs at concentrations of 0.1% and 0.2% rhamnolipids (RL) and 0.1% and 5% sophorolipids (SL) and were functionally characterized using scanning electron microscopy (SEM), texture analysis (mechanical strength and in vitro wound adhesion), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD) and exudate handling properties (pore analysis, swelling index, water absorption (Aw), equilibrium water content (EWC), evaporative water loss (EWL) and water vapor transmission rate (WVTR). The wafers were tactile and ductile in appearance with a hardness range of 2.7–4.1 N and can withstand normal stresses but are also flexible to prevent damage to newly formed skin tissues. Wafers were porous (SEM) with pore sizes ranging from 78.8 to 141 µm, and BSs were not visible on the wafer surface or pore walls. The BSs enhanced the porosity of the wafers with values above 98%, while the Aw and EWC ranged from 2699–3569% and 96.58–98.00%, respectively. The EWL ranged from 85 to 86% after 24 h while the WVTR ranged from 2702–3080 g/m2 day−1. The compatibility of BSs within the CARR-SA matrix was confirmed by seven characteristic functional groups which were consistently transmitted in the ATR-FTIR spectra. These novel medicated dressing prototypes can potentially help to achieve more rapid wound healing.