Preparation and characterization of curcumin and pomegranate peel extract chitosan/gelatin-based Films and their photoinactivation of bacteria

The development of photoantimicrobial films for food and medical devices decontamination is a continuous challenge. In this work, chitosan/gelatin-based films containing curcumin and pomegranate peel extract in different concentrations (0.5-5.0 mg photosensitizer g(-1) solution) were prepared and characterized by ultraviolet-visible spectroscopy, fluorescence spectroscopy, infrared spectroscopy and scanning electron microscope; their structural morphology (thickness and moisture content, solubility and swelling degree, and opacity) was also analyzed. The photobleaching results (up to 90%) demonstrated a potential application of the films in antimicrobial photodynamic therapy (aPDT). In the antimicrobial tests, the films displayed a significant photoantimicrobial effect reducing Staphylococcus aureus up to 4 log units, using a light source at 450 and 525 nm (50 J cm(-2)) for curcumin and pomegranate peel extract films, respectively. The results of this work open way for future development of photoantimicmbial films based on natural polymers, containing photosensitizers, for medical devices (e.g.: endotracheal tubes and catheters) and food packaging.

Automated summary

This study developed chitosan/gelatin-based films containing curcumin and pomegranate peel extract and demonstrated their potential application in antimicrobial photodynamic therapy. The films showed a significant reduction of Staphylococcus aureus and provide a direction for future development of photoantimicrobial films based on natural polymers.