Microbiological and cytotoxic perspectives of active PCL/ZnO film for food packaging
Hermano de Vasconcelos Pina, Andreza Josiany Aires de Farias, Francivandi Coêlho Barbosa, José William de Lima Souza, Ana Beatriz de Sousa Barros, Márcio José Batista Cardoso, Marcus Vinícius Lia Fook, Renate Maria Ramos Wellen
Abstract
Nanoparticles of zinc oxide (ZnO) were added to poly( ε -caprolactone) (PCL), and PCL/ZnO casting films were produced, afterwards films were characterized using Fourier Transform Infrared Spectroscopy (FTIR), x-ray Diffraction (XRD), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Additionally, antimicrobial and cytotoxic parameters were determined using microbial adhesion testing according to JIS Z 2801: 2000 (E) and agar diffusion method according to ISO 10993-5 2009 , respectively. From collected data, the chemical identity of individual components was kept and the surface control could be achieved changing the composition. According to FTIR spectra and using the Lambert-Beer law higher interaction ratios were met for higher ZnO content which is linked to antimicrobial action. As revealed by AFM analysis, at 5% of ZnO, nanoparticles were well dispersed in PCL matrix with uniform surface film. Analyses from antibacterial activity and cytotoxicity suggested pathogenic Staphylococcus aureus growth was hindered in ZnO films; specifically for PCL/ZnO 5% optimal antibacterial activity and toxicity absent were reached. Summing up, PCL/ZnO5% nanocomposites films offer great potential for commercial applications as active food packaging.