Zwitterionic polyaspartamides based on L-lysine side-chain moieties: Synthesis, nonfouling properties and direct/indirect nanogel preparation

•Synthesis of zwitterionic polyaspartamides based on L-lysine side chains was done.•Zwitterionic polyaspartamides indicate nonfouling properties and biocompatibility.•Preparation of zwitterionic polyaspartamide nanogels was performed.•The strategy of zwitterionic nanogel preparation could influence the morphology.