Bioinspired hybrid mesoporous silica-gelatin sandwich construct for bone tissue engineering

Mesoporous materials possessing pore sizes in the range 2-50 nm and surface reactive functionalities have elicited immense interest due to their exciting prospects in bone tissue engineering. Fabricating these mesoporous materials as continuous fibers adds an additional feature, which can be exploited for biomedical applications especially in tissue engineering. Though there are several factors involved in the remodeling of a damaged tissue, the design of scaffold plays an important role in tissue remodeling. The present work reports the fabrication of a bioinspired 3-D sandwich construct of mesoporous silica fibers and gelatin for bone tissue engineering. The silica nanofiber mesh and the gelatin gel mimic the collagen network and the glycosaminoglycan gel in the native extracellular matrix. Tetraethyl orthosilicate, polyvinyl pyrrolidone (PVP) and the tri-block copolymer P-123 were electrospun to fabricate continuous ordered mesoporous silica nanofibers by optimizing solution and process parameters. The 3-D scaffolds offered a suitable microenvironment for cell infiltration and tissue in-growth. The bioactivity of mesoporous silica fiber along with 2-D gelatin film was found to promote viability of human osteoblast-like cells (MG63) and alkaline phosphatase activity. Gene expression profiles of collagen I, alkaline phosphatase, osteocalcin, osteopontin and bone sialoprotein indicated good osteoblast proliferation, maturation and infiltration on the sandwich constructs. This novel silica gelatin 3-D scaffold possesses promising characteristics for enhanced bone tissue regeneration. (C) 2013 Elsevier Inc. All rights reserved.