Silk Films (Step 24, Options G and H)
Films provide a way to screen materials for in vitro or in vivo testing, pattern cells, embed molecules of interest, and test degradation and release. Here we present protocols to make both patterned (Step 24, Option G) and non-patterned silk films (Step 24, Option H) from aqueous solutions (Fig 6). Since the processing is water based, these techniques offer the flexibility to incorporate bioactive molecules. In order to sterilize, silk films can be incubated in 70 v/v% ethanol overnight and then rinsed in sterile phosphate buffered saline (PBS) or water. Film thickness and morphology can be assessed by either manually measuring it with a micrometer or by visually measuring it with an SEM.