Background: Bone defects can be severely debilitating and reduce quality of life. Osteoregeneration
can alleviate some of the complications in bony defects. For therapeutic use in future, a
single factor that can cause potent bone regeneration is highly preferred as it will be more costeffective,
any off-target effects will be more easily monitored and potentially managed, and for ease of
administration which would lead to better patient compliance and satisfaction.
Objective: We demonstrate that pigment epithelium-derived factor (PEDF), one such factor that is known
to be potent against angiogenesis, promotes osteoblastogenesis in mesenchymal stem cells in vitro, but
does not need co-encapsulation of cells in alginate bead scaffolds for osteogeneration in vivo.
Results: Osteogenic differentiation by PEDF in vitro was confirmed with immunoblotting and immunocytochemical
staining for bone markers (alkaline phosphatase, osteocalcin, osteopontin, collagen I),
calcified mineral deposition, and assay for alkaline phosphatase activity. PEDF-mediated bone formation
in a muscle pocket in vivo model was confirmed by microcomputed tomography (microCT), histology
(haematoxylin and eosin, Alcian blue staining), immunostaining for bone markers and for collagen
I-processing proteins (heat shock protein 47 and membrane type I matrix metalloproteinase).
Conclusion: PEDF therefore presents itself as a promising biological for osteogeneration.