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.

具有良好的防污和机械性能以及生物相容性的水凝胶在生物医学领域具有巨大的应用潜力。本文基于两性离子材料甲基丙烯酸磺基甜菜碱（SBMA）和天然多糖海藻酸钠（SA）制备了一种新的双网络（DN）水凝胶。PSBMA网络是共价交联的，而SA网络是通过Ca ^2+进行离子交联的。杂化交联双网络结构赋予DN水凝胶优异的机械性能（E = 0.19±0.01 MPa，σ = 0.73±0.03 MPa），快速的自恢复能力以及出色的抗疲劳性。此外，结果表明PSBMA / SA-Ca ²⁺DN水凝胶具有生物相容性，可抵抗非特异性蛋白质的吸收和微生物（如细胞和藻类）的粘附，具有出色的防污性能。PSBMA / SA-Ca ²⁺ DN水凝胶的这些独特特性使其成为生物医学应用（如人造结缔组织，可植入设备和水下设备）的有希望的候选者。