MOLECULAR STUDIES ON THE RESPONSE OF PERIODONTAL LIGAMENT CELLS TO MECHANICAL STRAIN IN VITRO

Abstract

Periodontal Ligament functions in a mechanically active environment. Most in-vitro studies used the traditional 2-D culture systems limiting the knowledge about the cells behaviour in-vivo. To overcome this limitation, we have engineered and characterized 3-dimensional constructs of the PDL by seeding cells into hydrogel matrices capable of being mechanically-deformed. Subjecting these constructs to biaxial cyclic strain of 12% did not have a significant effect on the viability of cells. Twelve of 18 extracellular genes analysed were expressed and upregulated at some experimental time point as was the synthesis of MMPs and TIMP-1. Cyclic compressive strain of 0.5lbs significantly increased the number of non-viable cells. Twelve of the twenty extracellular matrix genes analysed and fifteen apoptotic genes were expressed with significant synthesis of matrix proteins. These 3-dimensional culture systems are suitable as transitional in-vitro model for studying cell-cell and cell-matrix interactions in tooth support and investigating the pathogenesis of periodontal diseases.