Differentiation potential of SHEDs using biomimetic periosteum containing dexamethasone.

Mimicking the architecture of the natural environment in vivo is an effective strategy for tissue engineering. The periosteum has an important function in bone regeneration. However, the harvesting of autogenous periosteum has the disadvantages of donor site morbidity and limited donor sources. This study uses an innovative artificial periosteum that forms dexamethasone (DEX)-containing polyvinyl alcohol (PVA) nanofiber obtained from skin fibrous scaffold. The aim was to evaluate the effect on bone healing of osteogenic differentiation in stems originating from human exfoliated deciduous teeth (SHEDs) in vitro. The microstructure of fabricated periosteum was observed through SEM, and results showed the apparent homogenous distribution of porous structures. DEX was also found to be continuously released into the culture medium from the periosteum for 28 days. MTT results further revealed that fabricated periosteum was cytocompatible and non-toxic to SHEDs. After 21 days of induced culture, the expression of alkaline phosphatase activity and calcium mineralization notably increased. Osteogenic results showed high early and late osteoblast gene expression by RT-PCR analysis, such as collagen type I, Runx2, OPN, and OCN. The osteoblastic protein expression of BMP-2 and OCN was clearly observed as well under fluorescence microscopy. The results, which could be applied to bone regeneration, demonstrated that skin fibrous scaffold provided an osteoinductive environment for stem cells to differentiate and that PVA nanofiber was a suitable reservoir for osteogenic factors with controlled release profile.