Kuo-Hui Chiu (Aachen, DE), Mert Karpat (Aachen, DE), Johannes Hahn (Aachen, DE), Dr. Sanja Aveic (Aachen, DE), Prof. Dr. Horst Fischer (Aachen, DE)
Abstract text (incl. figure legends and references)
Introduction
The periodontal ligament (PDL) is a connective tissue that supports and surrounds the teeth and is vital for their proper function and movement. Orthodontic tooth movement (OTM) applies mechanical forces to the PDL, resulting in tissue remodeling. However, the intracellular signaling mechanisms involved in PDL regeneration in response to mechanical stimuli are not well understood due to a lack of suitable in vitro models.
Objectives
We developed a custom bioreactor for 3D dynamic cultivation of PDL-derived fibroblast (PDLF) to mimic native periodontal tissue during OTM. This 3D in vitro PDL model exposed to cyclic mechanical loading is a potential tool for investigating mechanotransduction effect and may provide insights into the molecular mechanisms underlying tissue remodeling during OTM.
Methods
Using a customized bioreactor, we provided cyclic stretching to PDLF cells embedded in a collagen-based hydrogel. Cell proliferation, morphology, and behavior were investigated and compared between static and dynamic conditions.
Results
We examined hydrogel stability, permeability, and biocompatibility to establish a proper PDLF cultivation model. We optimized stretching conditions using our dynamic bioreactor and observed increased cell proliferation (1.2-fold) and Periostin expression (3-fold). Glycosaminoglycan production analysis revealed extensive ECM remodeling, as evidenced by Collagen type I and Collagen type III expression. The dynamic cultivation period also increased hydrogel stiffness due to collagen fiber orientation and ECM remodeling.
Conclusion
With our customized bioreactor, we are able to apply mechanical stretching on PDLF cells embedded in collagen-based hydrogels. Therefore, the introduced dynamic bioreactor system is a highly effective device to investigate mechanobiological cues induced in the PDL during OTM.