A bilayered tissue engineered in vitro model simulating the tooth periodontium

Due to the complexity of the structure of the tooth periodontium, regeneration of the full tooth attachment is not a trivial task. There is also a gap in models that can represent human tooth attachment in vitro and in vivo.
Aim of the study: to develop a bilayered in vitro construct that simulates the tooth periodontium, for the purpose of tissue regeneration and investigation of physiologic and orthodontic loading.
Methods: Two types of materials were used to develop this construct: Sol-Gel 60S10Mg scaffold (University of Erlangen) representing the hard tissue component of the and commercially available Geistlich Bio-Gide® collagen membrane representing the soft tissue component of the tooth attachment. Each scaffold was dynamically seeded with periodontal ligament cells. The seeded scaffolds were either cultured separately, or combined in a bilayered construct, for 2 weeks. Characterization of the individual scaffolds and the bilayered constructs included biological characterization: (cell viability, SEM imaging to confirm cell attachment and viability qRT-PCR expression for periodontium regeneration markers), and mechanical characterisation of scaffolds and constructs.
Results: HPDLCs enjoyed a biocompatible 3D environment within the bi-layered construct components as demonstrated by live/dead images and LDH assay. Gene expression showed variation between individual scaffolds and constructs detached from the bilayer. Most genes showed a drop in expression in the construct except for markers of angiogenesis which showed their highest expression in Bio-Gide® detached constructs.
Conclusion and clinical significance: the development of this model is important for physiologic simulation invitro and for tissue regeneration purposes of the tooth periodontium.