Chiral coating-mediated interactions of bacteria with diverse biointerfaces

Bacteria, as living agents, have been widely used for microbial therapy due to their inherent ability to colonize different in vivo microenvironments, particularly in the gut and tumor. The interaction with diverse biointerfaces plays a critical role in bacterial colonization, and thereby determine the ultimate efficacy of microbial therapy. Although surface modification of bacteria with exogenous functional motifs can vary their interaction with surroundings, the effects of surface chirality of modified bacteria on mucous adhesion, tumor cell binding, and bacterial competition remain unknown. Here, we describe surface chirality-dependent selective interactions of bacteria to mucins, tumor cells, and pathogens. By coating bacteria with cationic polyethyleneimine modified with different chiral amino acids through electrostatic interaction, we find that bacteria coated with a D-chiral surface structure exhibit greatly increased adhesion to both mucins and tumor cells compared with those of L- and DL-structures. In addition, by adjusting the chirality of the coating, wrapped probiotic bacteria can selectively resist pathogenic bacteria, showing great potential to enhance colonization and positively modulate the gut and tumor microbiota. This work discloses surface chirality-dependent interaction of bacteria with different biointerfaces, showing a potential to tune the colonization and therapeutic effect of living bacterial agents for disease treatment.