Regulating Bacterial Culture through Tailored Silk Inverse Opal Scaffolds

Controlling the growth of microbial consortia is of great significance in the biomedical field. Selective bacterial growth is achieved by fabricating silk inverse opal (SIO) scaffolds with varying pore sizes ranging from 0.3 to 4.5 µm. Pore size significantly influences the growth dynamics of bacteria in both single and mixed-strain cultures. Specially, the SIO-4.5 µm scaffold is observed to be more favorable for cultivating S. aureus, whereas the SIO-0.3 µm scaffold is more suitable for cultivating E. coli and P. aeruginosa. By adjusting the secondary conformation of silk fibroin, the stiffness of the SIO substrate will be altered, which results in the increase of bacteria on the SIO by 16 times compared with that on the silk fibroin film. Manipulating the pore size allows for the adjustment of the S. aureus to P. aeruginosa ratio from 0.8 to 9.3, highlighting the potential of this approach in regulating bacterial culture.