The loss of teeth due to the progressive destruction of the tooth attachment is one of the major health problems in America and it is now becoming even more pronounced as the population ages. Cementum is a tissue uniquely and specifically adapted to facilitate anchoring collagenous fibers in an environment where repetitive forces are applied. The ultimate goal of this research is to develop a treatment strategy, based on bioengineering principles, that would augment the regeneration of cementum and restoration of functional tooth attachment. We propose to test the hypothesis that immobilizing integrin ligands on the mineralized tooth surface can be accomplished via the polyglutamate mineral-binding motif and that such enrichment in adhesive ligands would increase the recruitment and survival of cementoblastic precursors and accelerate their differentiation into cementoblasts. To test this hypothesis, we propose the following specific aims: 1. to evaluate the efficiency of the polyglutamate-mediated immobilization of bioactive synthetic peptides (integrin-binding ligands) to mineralized human dentin in vitro; 2. to evaluate the putative effects of integrin-binding synthetic ligands immobilized to mineralized human dentin on the pace of deposition, quantity and quality of human cementum formation employing an in vivo approach. To accomplish this, we will use the combined in vitro/in vivo model of human cementogenesis recently developed in our laboratory, since this system allows to study mechanisms of human cementogenesis on the cellular level in a direct and controlled manner.
In specific aim 1 we will test whether mineralized dentin is a good target for immobilizing biologically active adhesive peptides via the mineral-binding polyglutamate domain.
In aim 2, synthetic peptides composed of the integrin-binding and the mineral-binding polyglutamate motifs derived from bone sialoprotein (a relatively mineralized tissue-specific molecule, also abundant in cementum and dentin) will be attached to the mineralized human dentin carrier and human cementoblastic cells with a proven cementogenic potential in vivo will be loaded onto carrier, transplanted into immunodeficient mice and the formation of cementum as a function of carrier modifications will be evaluated by several qualitative and quantitative methods.
| Grzesik, Wojciech J; Narayanan, A S (2002) Cementum and periodontal wound healing and regeneration. Crit Rev Oral Biol Med 13:474-84 |
