Biomimetic cellulose/collagen/silk fibroin as a highly interconnected 3D hybrid matrix for bone tissue engineering

The limitations of the existing graft materials in the bone reconstruction practice will be met by the porous polymeric scaffolds with osteoconductive property. In this study, microcrystalline cellulose (CEL) and collagen (COL) along with the silk fibroin (SF) protein were fabricated into a porous hybrid matrix (CEL-COL-SF). The fabricated 3D hybrid matrix possesses interconnected porous architecture which helps in the cell adhesion, proliferation, migration and minerals deposition with excellent oxygen permeability. In addition, the CEL-COL-SF hybrid matrix showed excellent biocompatibility and cell proliferation when seeded with NIH 3T3 fibroblast cells and MG-63 osteoblast like cells. The osteogenic potential of the hybrid matrix was evaluated with MG-63 cells to reveal the sequence of events related to bone regeneration. The matrix exhibited increased alkaline phosphatase expression on day 7 as an initial event of bone regeneration process and paves way for the calci-fication process. As a result of the alizarin red activity, the calcium deposition on day 14 increases. Biominer-alization activity reveals the atomic ratio of calcium to phosphate in the hybrid matrix with 1.65, which mimics the atomic ratio of Ca/P of bone. Thus, results suggest that the hybrid matrix is a promising bone construct in bone tissue engineering.