Figure 1.

Schematic outline of the preparation of protein nanoparticles and its biomedical applications. In this layout, silk is shown as a representative protein. Silks are mainly obtained from the lepidopteron insects of the family Bombycidae (e.g. Bombyx mori) and Saturniidae (e.g. Antheraea mylitta). Silk proteins can be isolated from the cocoons and mature 5th instar larvae. Silk proteins are of two types: the fibrous protein fibroin and the glue protein sericin. The isolated silk proteins are further processed and engineered to obtain the regenerated silk protein solution. The regenerated silk solutions are then further subjected to processes like desolvation, coacervation, emulsification and electrospraying to obtain the silk-based nanoparticles. These silk-based nanoparticles are further utilized in such biomedical applications as drug delivery, enzyme immobilization, growth factors delivery, in vivo bioimaging, gene delivery, etc [67].