Medicine DentistryBone Substitute Gel
Composition: Gel contained in a syringe. Calcium phosphates 30% Water 70% Particle sizes: 100 to 200 nm Properties: a) Biocompatibility: Gels are perfectly tolerated and therefore biocompatible. Biomaterial: Bone regeneration material Our gel is pure phase synthetic hydroxyapatite with nano-particulate crystals in aqueous solution. Its chemical composition and crystalline structure match those of calcium phosphate in natural bone. Unlike other materials, the gel is not sintered and has an ideal surface area per unit weight that, combined with the size of its particles, makes it optimally resorbable. The gel is osteoconductive and so accelerates ossification. It assumes the support role of neoformed bone and during the healing process it is phagocytised, completely infiltrated and replaced by autogenous bone. Rapid: This type of product is revascularised early and bone regeneration occurs rapidly in a few months. Safe: The gel is free of any biological substance of animal or human origin, is aseptic and does not contain preservatives. It is possible to exclude immune reactions or disease transmission with complete confidence. In most of the studies radiological monitoring was used up to 6 months after implanting the bone substitute. The results of different tests in related studies have shown complete resorption of the product used. The time for complete resorption is estimated as 24 weeks. We tested biocompatibility of the hydroxyapatite gel during an animal study on rabbits over a period of 12 weeks. It was possible to see that the gel was in contact with the bone cortex on one side and disseminated in the medullary tissue on the other. The gel was perfectly integrated into the receiving tissues (cortical and medullary); there was no rejection and no inflammatory reaction, indicating perfect biocompatibility of the product. (Animal study reference 097/3/EA and histology analysis report 08-02TEKNIMED / Nanoparticules HAp lapins) b) Colonisation kinetics As opposed to bio-inert ceramics (alumina, zircon), they are bio-active and therefore have chemical exchanges with living tissues. After implantation, the material is the site of extracellular dissolution and cell-mediated degradation. These processes depend on the chemical (HAP, β-TCP, BCP) or physical (pores of the material) structure and the environment of the material. Biological fluids occupying the micropores are enriched in Ca, which finishes with the precipitation of apatite crystals similar to those in the neighbouring bone (process of calcification and not ossification). The process of osteoconduction may come into play, as well as subsequent Haversian bone remodelling. Calcium Phosphate gels are osteoconductive (but not osteoinductive), and require intimate contact with the receiving bone with no movement between bone and implant. The clinical outcome therefore depends on colonisation and resorption kinetics, which are affected by the chemical and physico-chemical natures of the implant; these criteria must therefore be fully controlled. During the animal study, 1 week after implantation, we observed the presence of a fine purple edging around some gel fragments disseminated in the medullary tissue. This edging was the beginning of bone mineralisation, evidence of bone neoformation. 4 weeks after implantation, we observed the presence of bone cells in the Nanogel. We could also detect bone formation and resorption activity, which were already well established at this stage. There was distinct mineralisation activity. 8 weeks after implantation, we observed distinct bone neoformation, even more pronounced than at the previous stage, with: trabeculae passing through the gel and forming a richly-vascularised bone structure. The gel is actually colonised by vessels promoting bone neoformation. There were large portions of bone tissue forming the boundary to areas of residual gel. 12 weeks after implantation, we found rare residual gel debris disseminated in areas of neoformed bone tissue, rich in blood vessels, evidence of bone regeneration and total integration. (Animal study reference 097/3/EA and histology analysis report 08-02TEKNIMED / Nanoparticules HAp lapins) c) Resorbability Resorption – osteogenesis phenomena are detected very early. In sections taken 8 weeks after implantation, the gel is completely fragmented and spanned by neoformed bone cells. We noted that these fragments contained blood vessels, evidence of significant regeneration activity. In sections taken 12 weeks after implantation, the gel is found more rarely (resorption), leaving space for richly-vascularised bone tissue. (Animal study reference 097/3/EA and histology analysis report n°08-02TEKNIMED / Nanoparticules HAp lapins) d) Mechanical properties: The disadvantage of calcium phosphate gels is their poor mechanical properties caused by their morphology. Their applications are often associated with the use of osteosynthesis devices.
NANOGEL® bone substitute comes in the form of an apatite gel designed to replace bone with an osteoconductive material. NANOGEL® is a material designed to fill bone defects that are not intrinsic to bone stability. It is simple to place NANOGEL® percutaneously, enabling the surgeon to use it in closed site filling indications. NANOGEL® is gradually resorbed and replaced by bone during the remodelling process.