In vitro effectiveness of microspheres based on Silk Sericin and Chlorella vulgaris or Arthrospira platensis for wound healing applications

Some natural compounds have recently been widely employed in wound healing applications due to their biological properties. One such compound is sericin, which is produced by Bombix mori, while active polyphenols, polysaccharides and proteins are synthetized by Chlorella vulgaris and Arthrospira platensis microalgae. Our hypothesis was that sericin, as an optimal bioactive polymeric carrier for microencapsulation process, could also improve the regenerative effect of the microalgae. A solvent-free extraction method and spray drying technique were combined to obtain five formulations, based on algal extracts (C. vulgaris and A. platensis, Chl and Art, respectively) or silk sericin (Ser) or their mixtures (Chl-Ser and Art-Ser). The spray drying was a suitable method to produce microspheres with similar dimensions, characterized by collapsed morphology with a rough surface. Art and Art-Ser showed higher antioxidant properties than other formulations. All microspheres resulted in cytocompatibility on fibroblasts until 1.25 mg/mL and promoted cell migration and the complete wound closure; this positive effect was further highlighted after treatment with Art and Art-Ser. To our surprize the combination of sericin to Art did not improve the microalgae extract efficacy, at least in our experimental conditions.