Simvastatin-loaded alginate bilayer membranes for wound dressing applications

Abstract

Recent studies have reported on the development of low-cost dressings that can deliver bioactive compounds to wounds, improving patients' quality of life. Our previous study successfully developed alginate-based single and bilayer membranes for slow release of simvastatin. This work aims to develop a new alginate bilayer dressing composed of membranes with different porosities and enhanced properties for sustained simvastatin delivery. These membranes were prepared by two drying processes; convection solvent evaporation and lyophilization, which are essential for modulating porosity and simvastatin release. The membranes were characterized using physical-chemical, thermal, morphological and mechanical analyses. Simvastatin release was accomplished using Franz's diffusion cells. The membranes' shelf-life and cytotoxicity were evaluated using human keratinocytes. Differences in membrane porosity influenced the morphological features of the membranes and their physical barrier properties. In vitro release studies showed that the bilayer membranes can sustain longer drug release than the single-layer membrane, which may benefit long-term treatment. Of interest, a more porous bottom layer allowed a faster simvastatin release during the first 6 h than a denser bottom layer. The shelf life analysis showed that, after 6 months, all membranes maintained around 98% of the initial drug content without changing their visual appearance. A cell viability assay showed that simvastatin-loaded alginate membranes are non-cytotoxic.