The effect of composition of calcium phosphate composite scaffolds on the formation of tooth tissue from human dental pulp stem cells

Different approaches towards making 3-dimensional (3-D) bioengineered tooth for future replacement therapy have been developed including scaffold-based tooth regeneration. However, selection of optimal scaffold for future clinical application remains a challenge. In the present study, we tested biocompatibility of four different types of 3-D scaffolds for tooth-tissue regeneration, including a pure poly(lactide-co-glycolide) (PLGA) (70/30, mol/mol) scaffold and three types of calcium phosphate contained composites scaffolds that were 50 wt% of PLGA combined with 50 wt% of hydroxyapatite (HA), tricalcium phosphate (TCP) or calcium carbonate hydroxyapatite (CDHA) respectively. These scaffolds were fabricated by the particle leaching in combination with phase separation technology. Surface modification of these scaffolds was further performed by an ammonia plasma treatment and anchorage of collagen technology. Effect of composition of the composite scaffolds on proliferation of human dental pulp stem cells (DPSCs) was accessed using in vitro MTT assay and in vivo BrdU labeling. Differentiation capability of the DPSCs in the scaffolds was analyzed by measurement of the levels of calcified tissue formation and ALP activity. Our results showed that while the calcium phosphate contained compound is able to support regeneration of tooth tissue effectively, the PLGA/TCP scaffold is more appropriate for the proliferation and differentiation of DPSCs. Furthermore, seeding of dissociated 4-dpn rat tooth bud cells on the PLGA/TCP scaffold generated dentin- and pulp-like tissues. Our results demonstrate that the PLGA/TCP scaffold is superior to the other three scaffolds for tooth-tissue regeneration, especially for dentin formation.