Chitosan/β-1,3-glucan/hydroxyapatite bone scaffold enhances osteogenic differentiation through TNF-α-mediated mechanism.

The role of TNF-α in bone healing process is still unclear and controversial. Although it is commonly believed that TNF-α inhibits osteogenic differentiation, there are few reports that identified a crucial role of TNF-α in enhancing bone regeneration process. The aim of this study was to prove that novel chitosan/β-1,3-glucan/HA scaffold (chit/glu/HA) may promote osteogenic differentiation via TNF-α-mediated mechanism and an autocrine stimulation of osteoblasts. It was demonstrated that normal human fetal osteoblasts (hFOB 1.19) maintained in conditioned medium containing increased level of TNF-α and harvested from hFOB 1.19 cells cultured on the chit/glu/HA scaffold (CM-chit/glu/HA) were in more advanced phase of osteogenic differentiation compared to the osteoblasts cultured in non-conditioned osteogenic medium and conditioned medium harvested from hFOB 1.19 cells cultured on the polystyrene plate. Cells cultured in CM-chit/glu/HA produced significantly more Col I protein, revealed 2-fold higher bALP activity, deposited 3-fold more calcium phosphate, and formed mineralized nodules. Thus, it was demonstrated that novel chit/glu/HA scaffold is promising material for bone regeneration applications to stimulate accelerated new bone formation as it enhances osteogenic differentiation via increasing TNF-α production by osteoblasts.