Structural and functional stabilization of sericin from Bombyx mori cocoons in a biopolysaccharide film: bioorigami for skin regeneration

Development and optimization of a bioorigami film with silk sericin was pursued for skin regeneration. Several formulations were produced, with varying integrated sericin contents, viz. 0, 1, 2, 5, 10, 20 and 50 mg_sericin mL_film^-1. The physico-chemical characteristics of the bioorigami films produced were evaluated via infrared spectrophotometry, X-ray diffraction, X-ray transmission, X-ray fluorescence, thermogravimetry, differential scanning calorimetry, transdermal protein permeation, kinetics of protein release from the bioorigami films and free radical scavenging activities. The mechanical resistance was also evaluated. The results by 2,2-diphenyl-1-picrylhydrazil (DPPH) assay suggest that the bioorigami films integrating crude sericin extract had capacity to sequester free radicals, exhibited prolonged release of the bioactive protein, good physico-chemical characteristics and adequate mechanical resistance. Specifically, the bioorigami film with 10 mgsericin mLfilm-1 proved to be able to release all the bioactive protein in a 12 h timeframe. The results suggest potential for use in biopharmaceutical application, specifically, as material for use in hydrogels.(author)