TGF-β Loaded Onto β-TCP Scaffold to Enhance Bone Regeneration

Objectives: Transforming Growth Factor-β (TGF-β) belongs to the TGF beta superfamily. It plays a pivotal role in osteogenesis by enhancing Mesenchymal Stem Cells (MSC) differentiation into osteoblasts. The aim of the study is to enhance bone regeneration in rat calvaria model by combining TGF-β loaded onto β-Tri Calcium Phosphate (β-TCP) synthetic scaffold.
Methods: The release kinetics of TGF-β (10, 20, 40 and 100ng/ml) from β-TCP was monitored by ELISA after 0, 1, 3, 6 and 9 hours. In-vitro biological effect of TGF-β (10, 40ng/ml) on MSC was determined by adhesion and proliferation assays using Alamar Blue. Evaluation of bone augmentation in-vivo following transplantation of TGF-β loaded on β-TCP was performed in a rat Guided Bone Regeneration (GBR) calvaria model. 14 sprague-dawley rats were divided into two groups: GBR+β-TCP (control), GBR+TGF-β (40ng/ml) + β-TCP (test). Following exposure and perforation of the calvaria a gold dome (7mm diameter, 5mm height) was filled with β-TCP with or without TGF-β, and fixed to the calvaria bone by fixation screws. Surgical flaps were repositioned and sutured.
Results: Release kinetics of TGF-β from scaffold correlated with the initial concentration of TGF-β: a larger amount of TGF-β was released in the concentration of 40ng/ml compared to other tested concentrations. Approximately 26% of initial TGF-β concentration was released in the first hour and remained relatively constant after two hours until the ninth hour. TGF-β encouraged cell adherence in the first two hours at 10ng/ml but higher concentrations showed opposing results indicating a suppression of cell adherence at 40ng/ml. Furthermore, strong suppression effect of TGF-β on the proliferation of MSC was observed in both concentrations after 24 and 48 hours.


Conclusions: The rapid release in the first hour of TGF-β from the scaffold may stimulate chemotaxis and improve the biochemical attraction of osteoblast-like cells, that may enhance bone regeneration.