Implantation of silicon dioxide-based nanocrystalline hydroxyapatite and pure phase beta-tricalciumphosphate bone substitute granules in caprine muscle tissue does not induce new bone formation

Abstract

BackgroundOsteoinductive bone substitutes are defined by their ability to induce new bone formation even at heterotopic implantation sites. The present study was designed to analyze the potential osteoinductivity of two different bone substitute materials in caprine muscle tissue.Materials and methodsOne gram each of either a porous beta-tricalcium phosphate (β-TCP) or an hydroxyapatite/silicon dioxide (HA/SiO2)-based nanocrystalline bone substitute material was implanted in several muscle pouches of goats. The biomaterials were explanted at 29, 91 and 181 days after implantation. Conventional histology and special histochemical stains were performed to detect osteoblast precursor cells as well as mineralized and unmineralized bone matrix.ResultsBoth materials underwent cellular degradation in which tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells and TRAP-negative multinucleated giant cells were involved. The ß-TCP was completely resorbed within the observation period, whereas some granules of the HA-groups were still detectable after 180 days. Neither osteoblasts, osteoblast precursor cells nor extracellular bone matrix were found within the implantation bed of any of the analyzed biomaterials at any of the observed time points.ConclusionsThis study showed that ß-TCP underwent a faster degradation than the HA-based material. The lack of osteoinductivity for both materials might be due to their granular shape, as osteoinductivity in goat muscle has been mainly attributed to cylindrical or disc-shaped bone substitute materials. This hypothesis however requires further investigation to systematically analyze various materials with comparable characteristics in the same experimental setting.

Synthetic bone substitute material comparable with xenogeneic material for bone tissue regeneration in oral cancer patients: First and preliminary histological, histomorphometrical and clinical results

“…A standard access through crestal incision was performed by the surgeon to develop a vestibular-based mucoperiosteal flap according to previously described methods. [56] Using the Piezosurgery ® device (Mectron, Carasco, Italy), antrostomy was performed to expose the Schneiderian membrane. No perforation of the sinus membrane occurred and no sinus pathology was observed.…”

“…All biopsies were analyzed histologically as previously described. [4567] All biopsies were harvested 6 months after implantation, simultaneously with the placement of the implants. The explants were then fixed in 4% neutral buffered formalin for 24 h and decalcified in 10% Tris-buffered ethylenediaminetetraacetic acid (Carl Roth, Karlsruhe, Germany) at 37°C for 10 days.…”

“…Recently, our workgroup has thoroughly investigated the tissue reactions and clinical outcome of a fully synthetic nanocrystalline hydroxyapatite (HA) bone substitute material (NanoBone ® [NB], Artoss, Germany) embedded in a matrix of structured silica gel in numerous studies in animals and humans. [4567] In an animal experimental trial, NB was implanted subcutaneously in Wistar rats to assess the vascularization and biodegradation of the biomaterial histologically and histomorphometrically. Although, there was no sign of new bone formation in this ectopic tissue, the graft material showed lower vessel density and vascularization than other synthetic bone substitute materials.…”

“…The absence of osteoinductivity and the above mentioned inflammatory cell response pattern, i.e., the primary role of multi-nucleated giant cells in the degradation of the materials, were also observed in muscle tissue of larger animals, like goats. [5]…”

Porous SiO2/HAp Coatings on Cp-Titanium Grade 1 Surfaces Produced by Electrophoretic Deposition

“…Many studies reported the importance of silica in bioactive materials for the bonding of bone [9,10]. Silica has three functions: (i) metabolic -to partake in cellular development and gene expression, (ii) chemical -as the nature of bonding to bone of bioglasses relates to the in vivo solubility of these glasses that in turn is a function of its silica content, (iii) mechanical -silica particles improve the strength of a hydroxyapatite coatings [9].…”