Tracing immunological interaction in trimethylamine N-oxide hydrogel-derived zwitterionic microenvironment during promoted diabetic wound regeneration

The diabetic wound healing is challenging due to the sabotaged delicate balance of immune regulation via an undetermined pathophysiological mechanism, so it is crucial to decipher multicellular signatures underlying diabetic wound healing and seek therapeutic strategies. Here, we develop a strategy using novel trimethylamine N-oxide (TMAO)-derived zwitterionic hydrogel to promote diabetic wound healing, and explore the multi-cellular ecosystem around zwitterionic hydrogel, mapping out an overview of different cells in the zwitterionic microenvironment using single-cell RNA sequencing. The diverse cellular heterogeneity has been revealed, highlighting the critical role of macrophage and neutrophils in managing diabetic wound healing. It is found that zwitterionic hydrogel can upregulate chemokine-secreted macrophages and downregulate extracellular traps (NETs)-neutrophils and facilitate their interactions compared with polyanionic and polycationic hydrogels, validating the underlying effect of zwitterionic microenvironment on the activation of adaptive immune system. These findings expand our horizons of the sophisticated orchestration of immune systems in zwitterion-directed diabetic wound repair and uncover new strategies of novel immunoregulatory biomaterials.