Supercritical solvent impregnation of alginate wound dressings with mango leaves extract

Abstract

Supercritical CO2 and a mango leaves extract were used to impregnate calcium-sodium alginate wound dressings. Two methods of impregnation were developed: batch and semi-continuous supercritical impregnation. The influence of parameters such as pressure, temperature and depressurization rate on the impregnation process was studied in terms of the antioxidant capacity of the samples and the impregnation load of polyphenols present in the mango leaves extract. The higher load of mango polyphenols and strong antioxidant capacity were obtained in batch mode at 30 MPa, 35°C and at fast depressurization rate. Semi-continuous mode behaved in a similar way but with lower results according to obtained impregnation percentages in the assayed conditions. The antioxidant capacity of the processed samples was verified by DPPH method, and to confirm the presence of the antioxidant particles and their distribution on the matrix, the processed alginate wound dressings were studied by UPLC-MS and Scanning Electron Microscopy (SEM).