Bone Regeneration with Wharton's Jelly-Bioceramic-Bioglass Composite

Abstract

The aim of this development is to optimize a bone substitute (BS) for use in tissue engineering. This is achieved through the combination of three phases in a biocomposite (BCO), in which each is reabsorbed in the site of implantation and replaced by autologous bone (patient's own). The inorganic phases are composed of irregular particles (150-300 microns) obtained by milling and sieving of a biphasic bioceramic (BC) of hydroxyapatite (HA of bovine origin) with 40% (wt.) β-tricalcium phosphate (β- TCP, obtained by chemical synthesis) and Bioglass type 45S5 (45SiO₂ -24,5CaO - 24,5Na2O - 6P2O5, in % wt.). Instead, the organic phase consists of collagen extracted from Wharton's jelly (part of the human embryonic tissue) from physical and chemical self-developed process. The BC is produced by mixture of HA and β-TCP (< 45 μm) and molding by gelcasting with albumin in aqueous solutions, drying and sintering at 1200 °C for 2 hours. The BG is obtained from the mixture of the oxides, melting at 1350 °C and cast onto metal. Each phase and BCO is subjected to studies by electron microscopy (SEM and EDS), X-ray diffraction (DRX) and infrared spectrometry (FT-IR). The biocompatibility is evaluated by in vivo studies using the laminar implant model in Wistar rats (n=40). Histological samples show high biocompatibility and ability to integrate with the bone tissue. 30 days after implantation, the material is completely reabsorbed and the bone regeneration process starts, the primary objective. The process developed allows the synthesis of a new BS with excellent biological properties for clinical use.