A novel in vitro co-culture system allows the concurrent analysis of mature biofilm and planktonic bacteria with human lung epithelia

•In vitro method examines epithelial growth with a mature biofilm of P.aeruginosa.•Biofilm does not cause epithelial cell damage as compared to planktonic bacteria.•Biofilm and planktonic adhere equally to cells; planktonic is internalized more.•Biofilm stimulates metabolism and IL-8 release by cells.•Novel co-culture method may help simulate chronic biofilm infections.

Pseudomonas aeruginosa establishes chronic infections by forming biofilms; however studies of the virulence have focused on the planktonic form. Few in vitro co-culture models exist to study biofilm infections. We present a novel in vitro co-culture method examining the interactions between mature P. aeruginosa biofilms and human lung epithelial cells.