Self-healable hyaluronic acid/chitosan polyelectrolyte complex hydrogels and multilayers

In this work, polyelectrolyte complexes (PEC) were obtained in form of nanometric polyelectrolyte multilayers (PEMs) and macroscopic hydrogels by electrostatic interactions between two natural polysaccharides: hyaluronic acid (HA) and chitosan (CHI). PEM was developed onto poly(ethylene terephthalate) (PET) surface by layer-by-layer approach. The characterization of both systems was carried out simultaneously by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission and scanning electronic microscopy (TEM and SEM). The rheological properties of PEC hydrogels were also analysed. The formation of the complexes was demonstrated due to electrostatic interactions, which in turn resulted being responsible for intrinsic self-healing ability. This is a highly demanded property in reducing replacements costs. Both, PEC hydrogels and multilayers showed self-healing properties within few minutes, this fact proves the versatility of HA/CHI complexes to easily obtain different forms of self-healable materials interesting as functional biomedical supports and coatings.