Development of chitosan-based curative films containing β- d -glucan obtained from Rhodotorula mucilaginosa yeast and containing bromelain extract carried in nanoparticles and liposomes

Polysaccharides are an attractive source for use in dressings due to their plentiful availability, low cost, biodegradability, biocompatibility and multifunctionality. In this work, we describe the preparation, characterization and evaluation of the healing capacity of chitosan films produced via the solvent evaporation method containing β- d -glucan obtained from Rhodotorula mucilaginosa yeast and bromelain extracted from pineapple ( Ananas comosus ), in free form or incorporated in liposomes or associated with polymeric nanoparticles. The films were characterized according to the swelling degree, thermal stability and enzymatic activity, and in vivo tests were performed to evaluate the films’ healing potential. The swelling degree of films with bioactive substances ranged from 110.69% to 185.82%, indicating that the films are suitable for use on non-exudative wounds. The films, when stored in a refrigerator, remained functional and maintained enzymatic activity for up to 30 days. Histopathological results showed the absence of edema, a low amount of inflammatory infiltrate and an increase in angiogenesis during the proliferative phase, with such events possibly involving the action of active compounds in films. The results showed promise for wound healing (wound contraction of 76.37%) using films containing bromelain and beta glucan for seven days.