Coaxial fibers modified with grape extract endowed with halochromic properties for potential detection of infection state in burns.

Burn wounds are among the most common and dangerous skin injuries for humans, causing denaturation of skin proteins and imposing serious constraints to the daily tasks of humans.

In recent years, the wet-spinning technique has been used in medical applications, such as wound dressings, due to its ability to generate nano- and microscale structures with different levels of organization, with open pores to improve cell interaction and with a set of chemical and physical properties that can be tuned to ease the process of cell maturation.

In this work, the development of coaxial fibers using the wet-spinning method for potential applications in burn treatment is proposed. The fibers were processed from biocompatible polymers with a core–shell structure.

The outer layer was made of cellulose acetate (CA) and polycaprolactone (PCL) modified with grape extract endowed with halochromic properties for detecting the level of infection of a potential burn. The inner layer was formed by sodium alginate (SA) loaded with natural extract (e.g., cinnamaldehyde) to combat infections and to endow the system with antioxidant properties to stimulate the regeneration of damaged cell tissue.

A color change was observed when solutions with different pH values, between 3 (light pink) and 10 (dark blue), were applied to the grape extract-loaded coaxial fibers. The coaxial structure was confirmed by brightfield microscopy and the elements composing the fibers were identified by Fourier-transform infrared spectroscopy. Antibacterial tests proved the bioactive agents’ inhibitory action, above 70%, against the bacteria Escherichia coli and Staphylococcus aureus. Antioxidant examinations attested to their ability in reducing 2,2-diphenyl-1-picrylhydrazyl. Data demonstrated the effectiveness of the engineered coaxial fibers for potential applications in burn wound care.