Deciphering Mechanism of Assembly of Keratin within Nanofibrous Matrix: Expanding the Horizon of Electrospun Polymer/Protein Composites

摘要

Keratin is unique due to its high cysteine content. This renders it with exceptional structural stability in native form, whereas in extracted form it makes them highly reactive. Hence keratin possesses higher capacity to assemble without stimulus, thus necessitating the study. The choice of extraction was limited to sulphitolysis and beta-mercaptoethanol (M-KH) based procedures, as these extracts exist in different structural levels evidenced through Circular Dichroic studies. Thermally induced irreversible structural transition of M-KH from alpha-helix to beta-sheet has resulted in lowering moisture loss peak of beta-mercaptoethanol extract based mat (PVA-M-T) to 80.4 degrees C compared to 120.6 degrees C of neat PVA fibers and 92 degrees C of sulphitloysis extract based mat. This signals presence of increased free water content in PVA-M-T after crosslinking. This helped PVA-M-T retain sufficient elongation at break values (similar to 31 ) without compromising its strength (similar to 8.5 MPa). Also PVA-M-T with increased beta-sheet content along with cell binding sequences (RGD, LDV and EDS) resulted in better protein-protein recognition and association thus favouring increased bioactivity.