Participação das células osteoprogenitoras e da matriz extracelular na regeneração de defeitos ósseos com aplicação de enxertos xenógeno e alógeno

Abstract

The bone defect can be caused by facial trauma, alveolar bone atrophy, alveolar bone resorption, cancers and tumors that lead to discomfort and changes in functions. Several materials are proposed for bone grafting, but they have limitations regarding the properties required for osteogenesis. The reconstruction of these defects is a challenge for tissue engineering. The industry has innovated by offering biomaterials with more than one phase in order to combine the properties of different materials to lead to osteoconduction and osteoinduction. In addition, they invest in nanotechnology, which also offers biomaterials with characteristics capable of mimicking bone structure. The aim of this study was to compare a xeno-biomaterial based on hydroxyapatite (HA) micrometer, with an allogeneic biomaterial based on HA and β-calcium triphosphate, nanometers. After creating a critical bone defect in Wistar rats calvaria, xenomaterial was inserted in the BO group, allogeneic material in the REG group and another CRTL group, without insertion of material, just clot. For general evaluation of the structures, staining for HE was performed. In addition, Goldner’s Trichrome staining were performed to assess the ossified areas and VEGF immunostaining to observe blood vessel formation. Staining was performed for HE by regressive method and staining for Goldner’s Trichrome, Weigert’s iron hematoxilin, Ponceau Acid Fuchsin dye, phosphomolybdic acid orange G and light-green solution were used. In immunostaining, antigen retrieval was performed. In immunostaining for OPN, the primary anti-Osteopontin antibody (Santa Cruz, sc-21742), diluted in PBS/BSA at 1% (1:1200) was used and for VEGF the primary anti-VEGF antibody (Santa Cruz, sc-1876), diluted in PBS/BSA at 1% (1:100) was used both were incubated with streptavidin VECTASTAIN® Universal Quick HRP Kit. Data were analyzed using one-way ANOVA, followed by the non-parametric Kruskal-Wallis test (p < 0.05) and Dunn´s post-test. The outcome of the histological analysis with HE and Goldner’s Trichrome and immunostaining with OPN and VEGF showed only collagen fibers in the CTRL group, in the BO Group and REG showed biomaterial associated with connective tissue and ossified areas. Histomorphometric analysis was statistically significant when comparing the REG and CTRL group with OPN, VEGF and Goldner's Trichrome. The mean of stained areas with Goldner's Trichrome, OPN and VEGF was expressively higher in the REG group. The conclusion was that the nanometric biomaterial is perfectly suitable for use in bone tissue reconstruction; the production of VEGF, which favors angiogenesis, and of OPN, which indicates ossification, was greater in the group with synthetic biomaterial, and the maintenance of only the clot does not favor osteogenesis.