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

ANDRES OZOLS,

Busan

Congreso; BITs 8th Annual World Congress of Regenerative Medicine & Stem Cell 2015; 2015

Yonsei University College of Medicine/Stem Cell Research Center for Drug Development, South Korea

The aim of this development is to optimize a bone substitute 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 (BCC) of hydroxyapatite (HA of bovine origin) with 40 % (wt.) -tricalcium phosphate (- TCP, obtained by wet chemical synthesis) and Bioglass (BG) (45SiO2-24,5CaO- 24,5Na2O-6P2O5, in % wt.). Instead, the biological matrix consists mainly of collagen extracted from Wharton's jelly (WJ), obtained from human umbilical cords, subject to proprietary physical and chemical processes. The BC is produced by mixture of HA and -TCP (< 45μm) 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 an energy dispersive energy, X-ray diffraction and infrared spectrometry. The histological chrono-dynamics of tissue response to BCO is evaluated, using the experimental model of laminar implant (Cabrini et al., 1993) in Wistar rats (n = 40) from the time of implantation up to 60 days. The BCO shaped as micro-implants (1 x 6 x 0.5 mm3), was implanted in both tibias. Euthanasia of animals was performed by overdose of anesthesia at T0, T1h, T24h, T7D, T14d, T30d and T60d of post- implementation times. The tibias were resected and fixed in 10% formalin, were radiographed, and demineralised, obtaining histological sections stained with HE. BCO provided an adequate biocompatibility at different evaluated times. From the first hour (T1h-T24h) good hydrophilic, surrounded with abundant erythrocytes, and the subsequent clot formation at the site of implantation were observed. At 7 days (T7D) formation of granulation tissue with abundant fibroblasts was observed. From T14d bone tissue formation around BCC and BG particles, interconnected through bone bridges, and was identified. Bone tissue was reticular after 14 days (T14) and laminar like after 30 days (T30 and T60). The new BCO synthesized and characterized, used as scaffold for bone tissue engineering is highly biocompatible. It allows the formation of laminar bone interconnecting BV and BCC particles, making it suitable for potential clinical application in implant and maxillofacial surgeries, which have begun.