Highly hemo-compatible, mechanically strong, and conductive dual cross-linked polymer hydrogels

A new class of hydrogels distinguished by electro-conductivity and high hemo-compatibility, which resemble biological tissues, are promising candidates for a plethora of biomedical applications. This work describes the design of highly elastic and biocompatible hydrogels using polypyrrole (PPy) as the conductivity media. The bio-inspired design of heparin-mimicking sodium alginate (HMSA) combined with tough alginate/polyacrylamide (PAM) is selected to form chemical and physical cross-linked binary hydrogel networks, while the incorporation of interfacial polymerized PPy endows the hydrogels with electro-conductivity. The resulting hydrogels exhibit a mesh-like hierarchical structure with excellent mechanical strength; moreover, the hydrogels show greatly enhanced electro-conductivity (up to 0.63 S m^-1). In addition, due to the presence of the unique heparin-mimicking structure, the hydrogels possess a desirable anticoagulant ability and biocompatibility demonstrated via antithrombotic evaluations together with cell culture observations. The facile synthesis of HMSA/PAM/PPy hydrogels and their robust physical, chemical and biological performance make them attractive components for the future generation of biosensors and bioelectrodes.