Micro and nano-patterned silk substrates for antifouling applications

A major problem of current biomedical implants is due to bacterial colonization and subsequent biofilm formation, which seriously affects their functioning and can lead to serious post-surgical complications. Intensive efforts have been directed towards the development of novel technologies that can prevent bacterial colonization while requiring minimal antibiotics doses. To this end, biocompatible materials with intrinsic antifouling capabilities are in high demand. Silk fibroin, widely employed in biotechnology, represents an interesting candidate. Here, we employ a soft-lithography approach to realize micro- and nano-structured silk fibroin substrates, with different geometries. We show that patterned silk film substrates support mammal cells (HEK-293) adhesion and proliferation, and at the same time they intrinsically display remarkable antifouling properties. We employ Escherichia coli as representative gram-negative bacteria and we observe a up to 66% decrease in the number of bacteria that adhere t...