Development of multicomponent interpenetrating polymer network (IPN) hydrogel films based on 2-hydroxyethyl methacrylate (HEMA), acrylamide (AM), polyvinyl alcohol (PVA) and chitosan (CS) with enhanced mechanical strengths, water swelling and antibacterial properties

The novel poly(2-hydroxyethyl methacrylate-co-acrylamide)/polyvinyl alcohol/chitosan (P(HEMA-co-AM)/PVA/CS) interpenetrating polymer network (IPN-CS) hydrogel films were fabricated by two-step free radical polymerization, aiming to enhance the tensile strength, water swelling and antibacterial activity compared to P (HEMA-co-AM)/PVA hydrogel (IPN-0%CS). The different weight ratios of PVA and CS components were firstly crosslinked by glutaraldehyde. Then P(HEMA-co-AM) copolymers were interpenetrated into the primary networks of PVA/CS and crosslinked by ethylene glycol dimethacrylate to form the IPN-CS hydrogels. The functional group analysis confirmed that the IPN-CS hydrogels were successfully synthesized. The crystallinity, T-g and T-m, microporous and surface area of IPN-CS hydrogels tended to increase significantly with increasing CS content. The swelling equilibrium and surface area of IPN-CS hydrogel exhibited a linearly relationship with CS content. The swelling behavior of IPN-CS hydrogels was best described by the pseudo-first order kinetics and followed a non-Fickian diffusion mechanism. The IPN-5%CS hydrogel film exhibited the highest tensile strength (22.4 MPa) which was increased 2.7 folds of IPN-0%CS. All IPN-CS hydrogels demonstrated an excellent antibacterial activity against E. coli. These results suggest that the IPN-CS hydrogel films have promising potential used as wound dressings.