Papers by Author: Borhane H. Fellah

Abstract: This study aims at evaluating bone growth in critical-sized femoral defects of rats filled with macro micro porous biphasic calcium phosphate ceramic (MBCP) cylinders surrounded or not by a resorbable collagen membrane. Femoral defects left empty (control) exhibited partial bone ingrowths after 3 and 6 weeks and were completely healed at 12 weeks. The defects filled with the collagen membranes appeared partially healed suggesting that the membranes constraint bone ingrowth. Bone formation occurred around the collagen membrane which partially degraded over time. In the MBCP/membrane group, bone has grown inside the macro pores of the MBCP cylinders. Bone ingrowth was more rapid and abundant in the defects filled with MBCP alone. The combination MBCP/collagen membrane may be beneficial for the reconstruction of large bone defects without using repetitive surgeries and autologous bone grafting.

Abstract: Porous Titanium Scaffolds were produced by using a rapid prototyping technique. These scaffolds were either coated or not with a calcium phosphate coating via an eletrodeposition method. Rat bone marrow mesenchymal stem cells were cultured on the scaffolds at a density of 106 cells/scaffold for a period of 3 days. Cell proliferation was measured by using the Alamar Blue assay. The scaffolds were observed by SEM and polarized light microscopy. Constructs were then implanted subcutaneously for 4 weeks in syngenic rats. Cells proliferated well after seeding. After subcutaneous implantation, histology and SEM revealed the presence of uniform coatings as well as Ca and P deposits in the non-coated scaffolds suggesting mineralization.

Abstract: The purpose of this study ass to investigate the addition of round 80-200m granules shape radiopaque agents (RA) to synthetic Injectable Bone Substitute to improve contrast performance for minimal invasive surgery MIS. Composites were obtained by mixing BaSO4, Bi2O3, Lu2O3 or GdPO4 with calcium deficient apatite CDA which decompose during sintering process in BCP (60% HA, 40% β-TCP). Each composite was characterized: by XRD, FTIR. Biocompatibility was tested in vitro and in vivo in bony site (3 weeks implantation in rats). Primary results show that the suitable radiopaque BCP/RA composite (radiopacity intensity, biological responses) appeared to be BCP/Ba. Next works will complete the current studies on biological performance in association with different kind of resorbable injectable bone substitute as suspension, gel or calcium phosphate cements.

Abstract: Autologous bone chips are widely used in orthopedic surgery to fill large defects due to osteoinductive property but are limited in quantity. Several groups have reported the formation of mineralized bone after implantation of bioceramics in ectopic sites of different animals. However, osteoinduction by bioceramics has not yet proved to be equivalent to those of autologous bone. In this study, we compare the bone inducing capability of autologous bone chips and synthetic biphasic calcium phosphate (BCP) ceramics granules sintered at various temperatures. Both materials were implanted in muscles and femurs of goats inside hollow containers for 6, 12 and 24 weeks and analyzed by histology. This study showed that bone tissue formed in contact with micro porous ceramics sintered at low temperature as well as autologous bone chips both in ectopic and intrafemoral sites of goats.