Desenvolvimento de micropartículas de quitosana e extrato de romã e avaliação de seu potencial antimicrobiano em filmes poliméricos

Abstract

The development of products with antimicrobial properties is of great relevance in the human and industrial health sectors, considering the need to control the proliferation and transmission of disease-causing pathogenic microorganisms. In this context, coatings with antimicrobial properties make up a research strand with potential applications in hospitals, industries and domestic environments. In addition, there is currently a demand for technologies with low environmental impact, such as those that use biopolymers and plant extracts with antimicrobial properties, and which are ecologically accepted approaches, thus making it possible to move towards replacing the use of environmentally harmful compounds. Added to this, the development of an antimicrobial coating for application on surfaces, that values chitosan, an abundant product derived from chitin, is a promising option that integrates these environmental policies. The objective of this work was to develop a polymeric film with antimicrobial properties by adding microparticles of chitosan and sodium tripolyphosphate (STPP) containing pomegranate extract. Using this technique, it was possible to synthesize microparticles with an encapsulation efficiency of 71%. The microparticles were characterized by FTIR to evaluate the contribution of the spectra of the wall and core materials. Qualitative antimicrobial assays demonstrated the antibacterial efficiency of the synthesized material against strains of Escherichia coli and Staphylococcus aureus, as well as a possible synergistic effect between chitosan and pomegranate extract. In addition, a polymeric film based on poly(vinyl alcohol) (PVAL) and microfibrillated cellulose (MFC) was developed, in which chitosan microparticles were incorporated. The characterizations of these coatings by SEM and FTIR demonstrated the presence of the components in the films, being possible to verify that while the PVAL brings a better structure to the coating, the MFC makes the film more mechanically resistant. The addition of an additive to the coatings with chitosan particles and pomegranate extract enhanced the characteristics of the film, resulting in a coating with prolonged antimicrobial action due to the controlled release of the pomegranate extract, showing a 75% reduction in CFU compared to the base film. In addition, they did not cause any morphological or physical properties changes when compared to the base film, maintaining similar contact angle values (45 – 53 o) and pencil hardness values to 9H.