Evaluation of tissue in repair with natural latex and / or hyaluronic acid in surgical bone defects.

This study evaluated the bone repair in surgical defects of rats treated with hyaluronic acid (HA) associated or not with Hevea brasiliensis fraction protein (F-1). Bone defect were created in 15 albino Wistar rats divided into 3 groups (n=5): Control group (1) - blood clot; HA group (2) - 0.5% hyaluronic acid; HAF1 group (3) - 0.1% F-1 protein fraction dissolved in 0.5% hyaluronic acid. After 4 weeks, the animals were euthanized and the bone repair was evaluated through histomorphometric analysis, zymography and immunohistochemistry. The neoformed bone area did not show a significant difference (p = 0.757), but there was a tendency for bone trabeculation to increase in the groups HA and HAF1. For immunohistochemically analysis, there was a difference in vascular endothelial growth factor (VEGF) labeling (p = 0.023), being higher in the groups HA and HAF1 than the control group. No significant difference in bone sialoprotein (BSP) (p = 0.681), osteocalcin (p = 0.954), however, significant difference in platelet endothelial cell adhesion molecule-1 (CD-31) (p = 0.040), with HAF1 group being significantly lower than the control. For zymographic analysis, there was no significant difference for metalloproteinase-2 (MMP-2) (p = 0.068), but there was a tendency to increase MMP-2 in the HA group. Despite the influence on angiogenic factors and the apparent tendency for greater trabeculation in the HA and HAF1 groups, there was no significant difference in the area of ​​newly formed bone tissue in the analyzed period.

Evaluation of tissue in repair with natural latex and / or hyaluronic acid in surgical bone defects

Abstract This study evaluated the bone repair in surgical defects of rats treated with hyaluronic acid (HA) associated or not with Hevea brasiliensis fraction protein (F-1). Bone defect were created in 15 albino Wistar rats divided into 3 groups (n=5): Control group (1) - blood clot; HA group (2) - 0.5% hyaluronic acid; HAF1 group (3) - 0.1% F-1 protein fraction dissolved in 0.5% hyaluronic acid. After 4 weeks, the animals were euthanized and the bone repair was evaluated through histomorphometric analysis, zymography and immunohistochemistry. The neoformed bone area did not show a significant difference (p = 0.757), but there was a tendency for bone trabeculation to increase in the groups HA and HAF1. For immunohistochemically analysis, there was a difference in vascular endothelial growth factor (VEGF) labeling (p = 0.023), being higher in the groups HA and HAF1 than the control group. No significant difference in bone sialoprotein (BSP) (p = 0.681), osteocalcin (p = 0.954), however, significant difference in platelet endothelial cell adhesion molecule-1 (CD-31) (p = 0.040), with HAF1 group being significantly lower than the control. For zymographic analysis, there was no significant difference for metalloproteinase-2 (MMP-2) (p = 0.068), but there was a tendency to increase MMP-2 in the HA group. Despite the influence on angiogenic factors and the apparent tendency for greater trabeculation in the HA and HAF1 groups, there was no significant difference in the area of ​​newly formed bone tissue in the analyzed period.

Resumo Este estudo avaliou o reparo ósseo em defeitos cirúrgicos de ratos tratados com ácido hialurônico (AH) associado ou não à fração proteica de Hevea brasiliensis (F-1). Foram criados defeitos ósseos em 15 ratos albinos Wistar divididos em 3 grupos (n = 5): Grupo controle (1) - coágulo sanguíneo; Grupo HA (2) - ácido hialurônico 0,5%; Grupo HAF1 (3) - fração proteica F-1 0,1% dissolvida em ácido hialurônico a 0,5%. Após 4 semanas, os animais foram submetidos à eutanásia e o reparo ósseo avaliado por meio de análise histomorfométrica, zimografia e imunohistoquímica. A área óssea neoformada não apresentou diferença significativa (p = 0,757), mas houve tendência de aumento da trabeculação óssea nos grupos HA e HAF1. Para a análise imunoistoquímica, houve diferença na marcação do fator de crescimento endotelial vascular (VEGF) (p = 0,023), sendo maior nos grupos HA e HAF1 do que no grupo controle. Nenhuma diferença significativa na sialoproteína óssea (BSP) (p = 0,681), osteocalcina (p = 0,954), no entanto, diferenças significativas foram encontradas para a molécula de adesão de células endoteliais plaquetárias-1 (CD-31) (p = 0,040), com o grupo HAF1 sendo significativamente inferior ao controle. Para a análise zimográfica, não houve diferença significativa para metaloproteinase-2 (MMP-2) (p = 0,068), mas houve tendência de aumento da MMP-2 no grupo HA. Apesar da influência sobre os fatores angiogênicos e da aparente tendência de maior trabeculação nos grupos HA e HAF1, não houve diferença significativa na área de tecido ósseo neoformado no período analisado.

Effectiveness of rhBMP-2 association to autogenous, allogeneic, and heterologous bone grafts.

Proteins with osteoinductive potential, especially recombinant human bone morphogenetic protein (rhBMP)-2, have large effects on cell growth and their differentiation. The aim of this study was to assess repair of bone defects in rat calvaria with different types of grafts associated with rhBMP-2, through immunohistochemistry and micro computed tomography (CT) analyses. A total of 35 male Wistar rats were selected, each weighing ~250 g, with a waiting period of 6 weeks from the creation of the defect to the sacrifice, and divided into five groups (n = 7): autograft plus 5 µg rhBMP-2 (AuG/BMP-2); allograft plus 5 µg rhBMP-2 (AlG/BMP-2); xenograft (heterologous) plus 5 µg rhBMP-2 (XeG/BMP-2); 5 µg rhBMP-2 (BMP-2) and the control group (n = 7). The micro CT reveal that all groups associating different bone grafts with BMP-2 showed increased bone formation compared to the control. The immunostaining show that osteocalcin and bone sialoprotein were higher in groups with BMP-2 than control group; BMP was high expressed in AuG/BMP-2, AlG/BMP-2, and BMP-2; vascular endothelial growth factor (VEGF) was more expressed in groups with BMP-2; VEGF-R2 was low to moderate in AuG/BMP-2, XeG/BMP-2, and BMP-2, predominantly moderate in AlG/BMP-2 and low in the control; CD-31 was predominantly moderate in AuG/BMP-2, AlG/BMP-2, and XeG/BMP-2, low to moderate in BMP-2 and low in the control. The results revealed that rhBMP-2 improved bone repair when administered alone, or when associated with different bone grafts.

Bone repair of critical-sized defects in Wistar rats treated with autogenic, allogenic or xenogenic bone grafts alone or in combination with natural latex fraction F1.

Bone grafts are used in the medical-surgical field for anatomical and functional reconstruction of lost bone areas, aiding the bone repair process by osteogenesis, osteinduction and osteoconduction. New materials such as F1 (fraction 1) protein extracted from the rubber tree Hevea brasiliensis have been investigated and currently present important properties for tissue repair, and are associated with neoangiogenesis, promoting cell adhesion and extracellular matrix formation. The main objective of this study was to investigate the association of F1 protein to different bone grafts in the repair of critical bone defects in the calvaria of Wistar rats. A total of 112 Wistar rats were divided as follows: autograft (AuG), allograft (AlG), xenograft (XeG), autograft/F1 (AuG-F1), allograft/F1 (AlG-F1), xenograft/F1 (XeG-F1), F1 (F1), control (CTL), with a waiting period of 4 and 6 weeks (w). The stereological AuG, AlG, AuG-F1 and AlG-F1 results had greater bone neoformation (p < 0.05). For immunohistochemistry, the angiogenic and osteogenic factors were higher for AuG-F1 and AlG-F1. TRAP-positive cells were higher in XeG-F1 and AlG (37 ± 9.53, 13.3 ± 4.16) (4 w) and XeG, AlG-F1 and XeG-F1 (20.33 ± 7.37; 15.25 ± 6.02, 19.33 ± 3.21) (6 w). For zymography, F1 showed increased gelatinolytic activity of MMP-2 and -9. It was concluded that the bone graft associated or not with F1 increases the angiogenic and osteogenic, biochemical and stereological factors.

Effect of treatment with simvastatin on bone microarchitecture of the femoral head in an osteoporosis animal model.

The objective of this study was to evaluate the microarchitecture and trabecular bone strength at the distal region of the femur, and its biomechanical properties with simvastatin administration with two different doses in ovariectomized (OVX) rats. Ninety rats were divided into six groups to evaluate treatment with the simvastatin drug (n = 15): SH (Sham surgery), SH-5 (5 mg simvastatin), SH-20 (20 mg simvastatin), OVX, OVX-5, and OVX-20. Euthanasia was performed at three different times, five animals per period: 7, 14, and 28 days. The effectiveness of the treatments was evaluated by mechanical testing and histomorphometric analysis of the femurs. The results of analysis by the linear model of mixed effects showed 20 mg of simvastatin results in increased trabecular bone after 14 days (P = 0.039) of ingestion in ovariectomized animals. However, ingestion of 5 mg of simvastatin is able to sensitize the trabecular bone only at 28 days (P = 0.005) of ingestion. In the mechanical tests stiffness improves within 28 days (P = 0.003). Regarding maximum strength, no statistical differences were observed. According to these results, it can be concluded that for a decrease in oral intake, longer treatment times are required. Microsc. Res. Tech. 79:684-690, 2016. © 2016 Wiley Periodicals, Inc.