Carbon Nanofiber Reinforced Nonmulberry Silk Protein Fibroin Nanobiocomposite for Tissue Engineering Applications

Natural silk protein fibroin based biomaterial are exploited extensively in tissue engineering due to their aqueous preparation, slow biodegradability, mechanical stability, low immunogenicity, dielectric properties, tunable properties, sufficient and easy availability. Carbon nanofibers are reported for their conductivity, mechanical strength and as delivery vehicle of small molecules. Limited evidence about their cytocompatibility and their poor dispersibility are the key issues for them to be used as successful biomaterials. In this study, carbon nanofiber is functionalized and dispersed using the green aqueous-based method within the regenerated nonmulberry (tropical tasar: Antheraea mylitta) silk fibroin (AmF), which contains inherent – R-G-D- sequences. Carbon nanofiber (CNF) reinforced silk films are fabricated using solvent evaporation technique. Different biophysical characterizations and cytocompatibility of the composite matrices are assessed. The investigations show that the presence of the nanofiber greatly influence the property of the composite films in terms of excellent conductivity (up to 6.4 × 10^–6 Mho cm, which is 3 orders of magnitude of pure AmF matrix), and superior tensile modulus (up to 1423 MPa, which is 12.5 times more elastic than AmF matrix). The composite matrices (composed of up to 1 mg of CNF per mL of 2% AmF) also support better fibroblast cell growth and proliferation. The fibroin-carbon nanofiber matrices can lead to a novel multifunctional biomaterial platform, which will support conductive as well as load bearing tissue (such as, muscle, bone, and nerve tissue) regenerations.