Avaliação do potencial osteogênico de células-tronco da polpa dentária em associação com biomateriais. Estudo In Vitro e In Vivo

Abstract

Although the bone tissue has a good regenerative capacity, there are defects which need bone grafting in order to properly recover the damaged tissue. Autogenous bone graft, the “gold standard” procedure, requires a second operation, with increased complexity and morbidity. In this study we investigated the osteogenic potential of stem cells obtained from the pulp of deciduous teeth (DSC) associated with biomaterials. We evaluated the effects of three biomaterials [Bone Ceramic (BC), Bonefill and a polyurethane derived from Ricinus communis (RC)] on in vitro cultures of DSC on cell proliferation, osteogenic differentiation (after staining with alizarin red), and cell morphology (by optical microscopy) and the three biomaterials were analyzed by scanning electron microscopy (SEM), and chemical composition [by electron dispersive spectroscopy (EDS)]. The DSC were easily obtained and showed good proliferative capacity. The BC stimulated cell proliferation and none of the biomaterials inhibited osteogenic differentiation. In the in vivo study, rats were divided into three groups and bone defects were prepared in the calvaria. The control group was filled with clot and the others were filled with the RC or the RC+DSC. After 15, 30 and 60 days they were sacrificed and the defect area was analyzed by digital radiography, optical microscopy, SEM, and EDS. There was no spontaneous regeneration of the defect. The group RC+DSC showed highest radiopacity at 15 days. The biomaterial worked as a mechanic filling and showed biocompatibility, evidence of osseointegration and no particles re-absorption. Only sparse ossified areas were identified which in the group RC+DSC were larger and more mature. Although the osteoinductive or osteogenic potential of RC+DSC was not clearly demonstrated, the association of cell therapy with biomaterials is promising and should be further investigated.