Biocompatible double network poly(acrylamide-co-acrylic acid)-Al3+/poly(vinyl alcohol)/graphene oxide nanocomposite hydrogels with excellent mechanical properties, self-recovery and self-healing ability
In this study, we have fabricated poly(acrylamide-co-acrylic acid)-Al3+/poly(vinyl alcohol)/graphene oxide (PAmAA-Al3+/PVA/GO) double network nanocomposite hydrogels by free-radical polymerization and freeze-thaw cycle in the presence of graphene oxide and aluminum ions. The pH-sensitivity, surface morphology and mechanical properties can be tuned by adjusting the contents of GO, PVA and Al3+. The resulting hydrogels have significant pH-sensitivity and an interconnected pore channel. The PAmAA-Al3+/PVA/GO hydrogels also exhibit high tensile strength, a large elongation at break and high toughness, which is due to the introduction of GO and formation of dynamic reversible bonds. The dynamic reversible bonds existed in the synthesized double network nanocomposite hydrogels could efficiently dissipate energy and recover the three-dimensional network. The combination of nanoparticles, dynamical reversible bonds and double network structure significantly improve physicochemical properties of hydrogels. Finally, subcutaneous implantation of the synthesized nanocomposite hydrogels in mice showed no local inflammatory response, indicating a good biocompatibility in vivo. In conclusion, the PAmAA-Al3+/PVA/GO double network nanocomposite hydrogels with tunable three-dimensional network structure, mechanical properties, good pH-sensitivity, self-healing ability and biocompatibility, are a promising biomaterial for tissue engineering.