Highly antifouling double network hydrogel based on poly(sulfobetaine methacrylate) and sodium alginate with great toughness

Hydrogels with good antifouling and mechanical properties as well as biocompatibility have great application potential in the field of biomedicine. In this paper, a newly double network (DN) hydrogel was prepared based on zwitterionic material sulfobetaine methacrylate (SBMA) and natural polysaccharide, sodium alginate (SA). The PSBMA network is covalently crosslinked while the SA network is ionically crosslinked by Ca2+. The hybrid crosslinked double network structure endows the DN hydrogel with excellent mechanical properties (E = 0.19 ± 0.01 MPa, σ = 0.73 ± 0.03 MPa), fast self-recovery ability as well as excellent fatigue resistance. Moreover, the results show that the PSBMA/SA-Ca2+ DN hydrogel is biocompatible and resists the absorption of non-specific proteins and adhesion of microorganisms, such as cells and algae, exhibiting outstanding antifouling properties. These unique characteristics of PSBMA/SA-Ca2+ DN hydrogel make it a promising candidate for biomedical application, such as artificial connective tissues, implantable devices, and underwater equipment.