Influence of sterilisations on silk protein-based materials

The authors investigated the influence of sterilisations on silk protein-based materials using the sericin gel films (SS-GFs) made from the Sericin Hope cocoons and the hornet silk cast films (HS-CFs) made from hornet cocoons. These two kinds of silk films seem to have a great potential as biomaterials for cornea engineering because they are transparent, have mechanical properties withstanding a surgical handling and have flexibility. These silk films inspired the authors to develop a novel artificial cornea, utilising the advantageous properties. An autoclave, an ethyleneoxide gas, an autoclave followed by an ethylene oxide gas, an ethanol solution and dry heat treatments were performed on the silk films. These sterilisation methods have different influences on cell adhesion in both of the SS-GFs and HS-CFs. The authors must consider the influence of denaturation while applying silk materials in biological evaluation or clinical use as a biomaterial. Although cell compatibility of SS-GFs and HS-CFs was affected by sterilisation processes, the sterilised films managed to retain transparency after any sterilisation process. In view of these points, SS-GFs and HS-CFs have a potential as a substitute for the corneal stroma.