Hierarchical mesoporous silica nanofibers as multifunctional scaffolds for bone tissue regeneration

Mesoporous materials with pore sizes between 2 and 50 nm have elicited widespread interest in catalysis, separation, adsorption, sensors, and drug delivery applications due to its highly ordered pore size along with high hydrothermal stability and easily modifiable surface functionalities. Fabricating these mesoporous materials as continuous fibers offers exciting vistas for biomedical applications especially in tissue engineering. The aim of the present study was to fabricate, characterize, and evaluate the cellular and gene expression of mesoporous silica with a long ordered fibrous morphology to support regeneration of bone tissue. Tetraethyl orthosilicate, polyvinyl pyrrolidone, and the tri-block copolymer P-123 were subjected to electrospinning to fabricate continuous ordered mesoporous silica nanofibers by optimizing solution and operation parameters. Mesoporous silica fibers with an average diameter of 470 nm and mesopores of dimension 5.97 nm were obtained. The combination of micropores, mesopores, macropores, and the nanofibrous morphology imparted excellent bioactivity to the mesoporous silica fibrous scaffolds as demonstrated by the proliferation of human osteoblast-like cells (MG63) and by the maintenance of its phenotype. The upregulation of collagen I, alkaline phosphatase, osteocalcin, osteopontin, and bone sialoprotein signifies the maturation of MG63 cells on the silica scaffold. Hence, these novel scaffolds are promising new biomaterials for orthopaedic applications.