Synthesis and characterization of zwitterionic peptides derived from natural amino acids and their resistance to protein adsorption

Abstract

Various functional groups can be easily introduced onto the poly(α,β-L-aspartic acid) by using different reagents to open the succinimide ring in polysuccinimide (PSI). In this work, two natural basic amino acids, L-histidine and L-lysine were used as the ring opening reagents to react with PSI. As a result, both positively and negatively charged moieties were introduced onto the same side chain simultaneously, which provides a nano-scale homogenous mixture of balanced charges. The chemical structures of the obtained polymers were confirmed by FT-IR and ¹H NMR spectroscopy. Zeta potential and turbidity measurements were applied to investigate the zwitterionic property of the polymers. Substrates pre-coated with the zwitterionic polymers exhibited good hydrophilicity and anti-protein-adsorption ability. What's more, the in vitro cytotoxicity test suggested that these peptide-based zwitterionic materials had good biocompatibility, indicating their good potential as non-fouling materials in the biomedical applications.