Co-assembling living material as an in vitro lung epithelial infection model

Biofilms are robust living 3D materials that play key roles in nature but also cause major problems, such as tolerance to antibiotic treatment. Recreation of these living structures in vitro is critical to understand their biology and develop solutions to the problems they cause. However, growing 3D biofilms in vitro is difficult primarily because of the limitations in developing matrices that mimic the inherent structural and compositional complexity of their extracellular milieu. Here, we report a living material based on the co-assembly of artificial sputum medium with bioactive peptide amphiphiles. We demonstrate its capacity to support the growth of 3D polymicrobial biofilms and build an interkingdom infected lung epithelial model to study the impact of the antibiotic ciprofloxacin. Our study offers a living material capable of growing functional 3D biofilms that simulate in vitro the nutritional and mechanical properties of these systems in vivo.