In situ fabrication of fully negatively-charged layer-by-layer nanofilms on a living cell surface.

Fully negatively-charged (FNC) layer-by-layer nanofilms were successfully assembled on a living cell surface for the first time using only poly(acrylic acid) (PAA) by introducing strain-promoted click chemistry to crosslink PAA layers. The resulting nanofilms retained their negative charges and showed higher adsorption of positively-charged molecules without affecting the cell viability.