The impact of structure on elasticity, switchability, stability and functionality of an all-in-one carboxybetaine elastomer

In this work, we designed and synthesized an all-in-one zwitterionic material (poly2-((2-hydroxyethyl)(2-methacrylamidoethyl)(methyl)ammonio)acetate (pCBMAA-1)) bearing elasticity, switchable antimicrobial/antifouling properties, and stability. Zwitterionic materials have drawn special attention due to their outstanding antifouling properties; however, conventional zwitterionic materials lack tunable elasticity, stability and antimicrobial properties. We addressed these challenges by integrating all desired properties into a single zwitterionic molecule through rational design. pCBMAA-1 hydrogel showed typical elastomeric stress–strain curves with low Young's modulus and high yield strain, in both tensile and compression tests. About 65% tensile strain and 85% compressive strain were achieved. pCBMAA-1 hydrogel can switch between cationic antimicrobial form and zwitterionic antifouling form. In its cationic ring form, pCBMAA-1 hydrogel killed 99.5% of attached bacterial cells and then released 95% of killed cells. pCBMAA-1 surfaces highly resisted the protein adsorption from 100% blood plasma and serum. The amount of adsorbed protein was below the detection limit (0.3 ng cm−2) of the SPR sensor. Compared to existing zwitterionic materials, this material showed the dramatically improved stability in both basic and acidic conditions. We believe that this all-in-one material will broaden the application spectrum of zwitterionic materials to a great extent.