Plasma-Assisted Deposition of Silk Fibroin on Different Surfaces

The development of simple and versatile methods for the deposition of biocompatible coatings to protect or functionalize a range of materials with different shapes is an important challenge. In this study, a versatile, room-temperature process is presented for the deposition of silk fibroin on different materials viz., glass, polyethylene terephthalate, Ti alloy, and poly(dimethylsiloxane). Coating with thin fibroin films is achieved using an atmospheric plasma torch, wherein a silk-fibroin aerosol solution is used as the working gas. The method consists of two sequential processes: plasma modification of the surface, followed by plasma-assisted deposition. This allows enhanced adhesion of the protein to the underlying surfaces, and the deposition even on non-planar and flexible substrates. The deposited films are characterized by optical microscopy, atomic force microscopy, and scanning electron microscopy. Primary and secondary structures of the surface-attached fibroin films are investigated by Fourier transform infrared spectroscopy. The proposed approach offers a tunable and controllable strategy for the controlled deposition of proteins on complex surfaces, for a wide range of biomedical and technological applications, including dentistry and bioelectronics.