Gentamicin modified chitosan film with improved antibacterial property and cell biocompatibility

•Surface of chitosan film were successfully modified via gentamicin grafting.•The gentamicin modified chitosan film has good hydrophilicity and biocompatibility.•Gentamicin grafting treatment improves the antibacterial properties of the film. Gentamicin modified chitosan film (CS-GT) was produced using a three-step procedure comprising: (i) the chitosan solution was air-dried to form a chitosan (CS) film, (ii) using citric acid to generate the amide and carboxyl groups on the surface of CS, (iii) the CS with surface carboxyl groups was modified by grafting of gentamicin. After modification, this CS-GT film has excellent hydrophilicity and biocompatibility. It is very evident that the gentamicin grafting treatment significantly improves the antibacterial properties of the CS film. Our preliminary results suggest that this novel gentamicin modified chitosan film, which can be prepared in large quantities and at low cost, should have potential application in biomedical applications.