Characterization of OSA starch-based films with nut-byproducts extracts for potential application as natural wound dressing

OSA-starch based bioactive films with pecan nutshell or hazelnut skin extracts were prepared, characterized, and evaluate. The hemocompatibility assay showed that bioactive films with extracts are slightly hemolytic. Bioactive films with 0.25% and 0.50% (w/v) of extracts showed antibacterial activity against S. aureus , S. epidermidis and K. pneumoniae . Due to the hemocompatibility and microbial assays, only films with 0.25% and 0.50% of each extract were characterized. Bioactive films depicted a homogeneous surface and compact structure, due to plasticization and molecular interactions through hydrogen linkages between extracts and modified starch network, confirmed by Fourier-transform infrared spectroscopy (FTIR). The water uptake capacity (~ 100% after 24 h), water vapor transmission rate (WVTR) (2300–2600 g/m 2 ·day) and contact angle values (92–100°) confirmed bioactive films have moderate water properties. Finally, mechanical properties of bioactive films showed an elastic behavior with young´s modulus values lower than 25 MPa and elongation percentages around 290%, indicating a plasticizing effect of the extracts. Overall results suggest elaborated bioactive films could have potential application as wound dressings. Graphical abstract