Attachment and growth of cultured fibroblast cells on silk protein matrices

Abstract The attachment and growth of L‐929 cells on films made of Bombyx mori silk proteins—fibroin and sericin and their mixtures—was studied by a cell culture method. Both cell attachment and growth were dependent on a minimum of around 90% sericin in the mixture. The results from electron micrography as well as from the DSC measurements supported the notion that the mixture of the two proteins fibroin and sericin has a phase‐separated structure in the solid state. The observed minimum of sericin in the cell attachment and growth is thought to be a result of this phase‐separated structure. Films of pure component proteins (i.e., 100% fibroin or sericin) exhibited as high a cell attachment and growth as collagen, a widely used mammalian cell culture substrate. However, a morphological study of the attached cells revealed that the cells attached to silk fibroin were extended and had a spindle shape, just like the cells attached to collagen, while the cells attached to the silk sericin had a different shape. It is concluded, therefore, that the attachment condition on silk fibroin is ideal for the viability, growth and function of the cells. © 1995 John Wiley & Sons, Inc.