Cooperative Calcium Phosphate Deposition on Collagen-Inspired Short Peptide Nanofibers for Application in Bone Tissue Engineering.

In recent years, immense attention has been devoted over the production of osteoinductive materials. To this direction, collagen has a dominant role in developing hard tissues and plays a crucial role in the biomineralization of these tissues. Here, we demonstrated for the first time the potential of the shortest molecular pentapeptide domain inspired from collagen toward mineralizing hydroxyapatite on peptide fibers to develop bone-filling material. Our simplistic approach adapted the easy and facile route of introducing the metal ions onto the peptide nanofibers, displaying adsorbed glutamate onto the surface. This negatively charged surface further induces the nucleation of the crystalline growth of hydroxyapatite. Interestingly, nucleation and growth of the hydroxyapatite crystals lead to the formation of a self-supporting hydrogel to construct a suitable interface for cellular interactions. Furthermore, microscopic and spectroscopic investigations revealed the crystalline growth of the hydroxyapatite onto peptide fibers. The physical properties were also influenced by this crystalline deposition, as evident from the hierarchical organization leading to hydrogels with enhanced mechanical stiffness and improved thermal stability of the scaffold. Furthermore, the mineralized peptide fibers were highly compatible with osteoblast cells and showed increased cellular biomarkers production, which further reinforced the potential application toward effectively fabricating the grafts for bone tissue engineering.