Inflammatory-Driven Angiogenesis in Bone Augmentation with Bovine Hydroxyapatite, B-Tricalcium Phosphate, and Bioglasses: A Comparative Study

Abstract

Introduction The clinical use of bioactive materials for bone augmentation has remained a challenge because of predictability and effectiveness concerns, as well as increased costs. The purpose of this study was to analyse the ability to integrate bone substitutes by evaluating the immunohistochemical expression of the platelet endothelial cell adhesion molecules, vascular endothelial growth factor, collagen IV, laminin, and osteonectin, in the vicinity of bone grafts, enabling tissue revascularization and appearance of bone lamellae. There is a lack of in vivo studies of inflammatory-driven angiogenesis in bone engineering using various grafts. Methods The study was performed in animal experimental model on the standardized monocortical defects in the tibia of 20 New Zealand rabbits. The defects were augmented with three types of bone substituents. The used bone substituents were beta-tricalcium phosphate, bovine hydroxyapatite, and bioactive glasses. After a period of 6 months, bone fragments were harvested for histopathologic examination. Endothelial cell analysis was done by analysing vascularization with PECAM/CD31 and VEGF and fibrosis with collagen IV, laminin, and osteonectin stains. Statistical analysis was realized by descriptive analysis which was completed with the kurtosis and skewness as well as the Kruskal-Wallis and Mann-Whitney statistical tests. Results The discoveries show that the amount of bone that is formed around beta-tricalcium phosphate and bovine hydroxyapatite is clearly superior to the bioactive glasses. Both the lumen diameter and the number of vessels were slightly increased in favor of beta-tricalcium phosphate. Conclusion We can conclude that bone substitutes as bovine bone and beta-tricalcium phosphate have significant increased angiogenesis (and subsequent improved osteogenesis) compared to the bioactive glass. In our study, significant angiogenesis is linked with a greater tissue formation, indicating that in bone engineering with the allografts we used, inflammation has more benefic effects, the catabolic action being exceeded by the tissue formation.

Current Application of Beta-Tricalcium Phosphate in Bone Repair and Its Mechanism to Regulate Osteogenesis

“…Given the critical role of Ca 2+ in angiogenesis, it is not surprising that β-TCP can effectively induce neovascularization. In a rabbit tibial defect model, significantly increased angiogenesis measured by average number of blood vessels, was observed in the β-TCP group (4.47 ± 0.2) compared with the bioactive glass group (1.58 ± 0.246) (Anghelescu et al, 2018). In clinical practice, similar results were observed when using β-TCPbased dental implants (Dautova et al, 2018).…”

Histomorphometric, Immunohistochemical, Ultrastructural Characterization of a Nano-Hydroxyapatite/Beta-Tricalcium Phosphate Composite and a Bone Xenograft in Sub-Critical Size Bone Defect in Rat Calvaria

“…A comparative biomaterial study conducted by Anghelescu et al, albeit in rat tibial bone, demonstrated that xenogenic HA (Bio Oss™) and β-TCP exhibited higher platelet endothelial cell adhesion molecule (PECAM 1) and vascular endothelial growth factor (VEGF) immunolabeling than other types of bioactive glasses [ 27 ].…”

Morphological Characteristics of the Osteoplastic Potential of Synthetic CaSiO3/HAp Powder Biocomposite

“…Further, the pericytes in bone tissue are capable of transformation into osteoblasts [ 37 ], and this fact can be interpreted as an osteoinductive phenomenon for a disperse CaSiO 3 /HAp biocomposite as a structural powder. Ions of calcium and phosphate are osteoinductive factors for mesenchymal cells that stimulate their transformation into osteoblasts and contribute to the genesis of new bone tissue [ 38 ]. The graft acted as a component of a regenerative process of bone tissue.…”

“…Additionally, in the paper mentioned it was experimentally proved that a biological composite with a macroporous structure has a higher mechanical strength. The rate of its resorption and osseointegration is higher in comparison with that of pure HAp [38], which is similar to the comparison of materials based on tricalcium phosphate (TCP) and their composite forms [39]. Thus, it should be noted that for the targeted tissue engineering of the alveolar bone branches, the mentioned biocomposite may represent a promising perspective, since it is able to provide a long duration of resorption, integration into the bone matrix, the stimulation of the activation of mesenchymal stem cells into osteoblasts, the stimulation of vascular growth, and low toxicity.…”