Double functionalization of chitosan based nanofibers towards biomaterials for wound healing

The paper reports the preparation and characterization of a series of functionalized chitosan nanofibers designed for tissue engineering. Their functionalization was done by imination with two aldehydes with complementary bioactivity, one possessing antimicrobial activity and the other one having potential to enhance it by improving the cell permeability. The degree of imination of the fibers and the dynamic character of the imine units were investigated by FTIR, 1H NMR and UV-vis spectroscopy, while their morphology was assessed by scanning electron microscopy and polarized light microscopy. The swelling ability and biodegradation were determined in conditions mimicking the physiological environment, i.e. saline buffer and lysozyme medium at 37 degrees C. Preliminary biocompatibility and antimicrobial properties were evaluated by MTS assay on normal human dermal fibroblasts, and by disk diffusion method against relevant bacterial and fungal reference strains. The fibers showed fast swelling, biodegradation in the presence of lysozyme, biocompatibility and antimicrobial activity. It was concluded that the imination of chitosan nanofibers with two different aldehydes is a promising route towards biomaterials with improved properties for tissue engineering.