Physicochemical, antibacterial properties and cytocompatibility of starch/chitosan films incorporated with zinc oxide nanoparticles

Zinc oxide nanoparticles (ZnO-NPs) with attractive antibacterial properties have been widely used in the field of antimicrobial films. In this study, ZnO-NPs, corn-starch (ST), chitosan (CS) as materials and glycerol as plasticizer. To avoid the pungent smell of acetic acid, L-malic acid was used to prepare chitosan solution. The effect of ZnO-NPs incorporated CS/ST films on physicochemical properties, antimicrobial activity and cytocompatibility were investigated. The results showed that the composite films with 6%(w/w) ZnO-NPs, the mass ratio of CS/ST was 1:1, whose TS value reached 19.64 +/- 0.75 MPa, possessed the best physicochemical properties comparing to the composite films without ZnO-NPs. Furthermore, the inhibition zone diameters of the composite films with ZnO-NPs against Staphylococcus aureus were 29.36 +/- 2.40 mm, 24.90 +/- 0.40 mm and 22.00 +/- 0.34 mm respectively after 0, 7 and 14 days of sustained release, which was higher than the inhibition zone diameters of the composite films without ZnO-NPs (p < 0.05). Moreover, cell viability of MC3T3-E1 cells on the surface of the composite films with ZnO-NPs was still 95.63 +/- 3.17 % (p < 0.05), showing excellent cytocompatibility. The overall results of this study pointed out that the CS/ST/ZnO-NPs films have potential application in food packaging industry and medical device packaging industry.