Preparation of Silk Fibroin Nanoparticles and Enzyme-Entrapped Silk Fibroin Nanoparticles

After silk fiber is degummed in boiling 0.2% Na₂CO₃ solution, the degummed fibroin fiber could be dissolved in highly concentrated neutral salts such as CaCl₂. The partially degraded polypeptides of silk fibroin, commonly called as regenerated liquid silk, could be obtained via water dialysis. The silk fibroin nanoparticles (SFNs) or enzyme-entrapped SFNs are prepared rapidly from the liquid silk by using acetone. The globular particles with a range of 35-125 nm in diameter, are water-insoluble but well dispersed and stable in aqueous solution. The nanoparticles are potentially useful in biomaterials such as cosmetics, anti-UV skincare products, and surface improving materials, especially in enzyme/drug delivery system as vehicle. Here, a detailed protocol for SFNs and enzyme-entrapped SFNs preparation is described.