Bioactive Nanocomposites for Dentinogenic Restoration.
- Restoration of bone after injury is essential. There are two current repair mechanisms, root canals and bioactive molecule implants, both of which can be costly and have inconsistent material properties with the target tissue. Therefore, novel bioactive chimeric proteins were developed containing a spider dragline silk domain for strength and stability and a domain containing either an R5 or A3 ... read moresilica precipitating sequence for biomineraliation. We hypothesized that the varying number of silk repeating sequences, in combination with each silica precipitating sequence, would differentially precipitate silica and affect the biomineralization capabilities of human mesenchymal stem cells (hMSCs) in vitro. The protein films precipitated silica particles on the surfaces. The particles ranged in size from 200-400nm and were separated (as opposed to agglomerated) on films treated with glycerol. hMSCs differentiated toward osteoblasts and deposited calcium phosphate, a hydroxyapatite precursor and major organic component of bone. The cells were viable and showed osteoinductive properties, but displayed inconclusive genetic expression of genetic bone markers (bone sialoprotein, BSP, alkaline phosphatase, ALP, and collagen type I, ColI). Overall, we achieved our specific aims of precipitating silica and characterizing the chimeric protein films based on their sequences and successfully differentiated hMSCs towards osteoblasts that achieved biomineralization.read less