High strength and antibacterial polyelectrolyte complex CS/HS hydrogel films for wound healing.

We report a simple and facile self-assembly approach to fabricate polyelectrolyte complex (PEC) hydrogel films with positively charged chitosan (CS) and negatively charged heparin sodium (HS) by combining hydrogen bonding and electrostatic interactions. The CS/HS hydrogel films exhibited excellent tensile strength and toughness, good self-recovery ability, superior water absorbency, and pH-dependent surface charge characteristics. The gelation mechanism was investigated by zeta potential measurements. The CS/HS hydrogel films exhibited high antibacterial efficacy against E. coli at selected pHs or when coordinated with various metal ions and a significant effect on accelerating wound healing. The self-assembly approach presented in this work may serve as a generic strategy for the fabrication of novel multi-functional PEC hydrogels for broad biomedical applications.