Avaliação dos efeitos dos fatores de crescimento TGF-1 e BMP-4, carreados por meio de lipossomas, no reparo ósseo de alvéolos dentários em ratos

Abstract

The process of bone repair is mediated by a cascade of molecular events, attended several growth factors and their receptors. Knowledge of signaling molecules during the dynamic healing and remodeling of periodontal tissues, can make treatment faster and allow, through the biological modulation, the scope of clinical, aesthetic and functional objectives, with higher quality and lower tissue involved damage. In this work we evaluate BMP-4 and TGF-1 potential induction bone formation adduced by liposomes molecules alone or associates during alveolar repair process followed extraction of second molar maxillary rats. 112 male Wistar animals weighing between 250-300g were used. Histomorphometric and histological analyzes evaluated blood vessels and bone formation during alveolar bone repair. The results revealed a higher vascular proliferation and an increase percentage of trabecular bone in sockets treated with BMP-4 or TGF-1, adduced by liposomes, administered isolated or in association when compared with those filled with blood clot or treated with L-(empty liposome), P (PBS), BP (BMP-4 adduced in PBS) and TP (TGF-1 adduced in PBS). Furthermore, the expression of two indicators of bone repair, fibronectin and type III collagen, was evaluated in the early stages of healing alveolar by immunohistochemistry. An increase in expression of both molecules detected at 3 days was observed, followed by a peak expression at 7 days. Lower levels of immunoreactivity were observed in cavities filled with blood clot and treated with L, P, BP and TP when compared to sockets treated with BL (BMP 4/lipossome), TL (TGF-1/lipossome) and BTL (BMP-4 and TGF-1 in liposome administered in the same well). In conclusion, the present study showed the efficacy of growth factors TGF-1 and BMP-4 as accelerators in the process of tooth socket bone healing when administered via liposomes.