Osteoconductivity of strontium-doped bioactive glass particles

A.A.GORUSTOVICH, J.M.PORTO L¨®PEZ, M.B.GUGLIELMOTTI, R.L.CABRINI

Buenos Aires

Jornada; XXIV Reuni¨®n anual de la Asociaci¨®n Argentina de Osteolog¨ªa y Metabolismo Mineral; 2007

Asociaci¨®n Argentina de Osteolog¨ªa y Metabolismo Mineral

OSTEOCONDUCTIVITY OF STRONTIUM-DOPED BIOACTIVE GLASS PARTICLES Gorustovich Alejandro,1,2 Steimetz Tammy,3 Cabrini R¨®mulo L,3 Porto L¨®pez Jos¨¦ M2,4 1 Res Laboratory, National Atomic Energy Commission. CNEA Reg. Noroeste, Salta1,2 Steimetz Tammy,3 Cabrini R¨®mulo L,3 Porto L¨®pez Jos¨¦ M2,4 1 Res Laboratory, National Atomic Energy Commission. CNEA Reg. Noroeste, SaltaRes Laboratory, National Atomic Energy Commission. CNEA Reg. Noroeste, Salta 2CONICETCONICET 3 Dept of Oral Pathology, School of Dentistry, University of Buenos AiresDept of Oral Pathology, School of Dentistry, University of Buenos Aires 4 Ceramics Division, Res Institute for Materials Science and Technology, Mar del Plata There is accumulating evidence that strontium (Sr) has positive effects on bone formation. Thus, it is reasonable to expect that its presence in biomaterials can enhance the osteoconductivity leading to osseointegration. The aim of the present study was to evaluate the osteoconductivity of Sr-doped bioactive glass (BG) particles implanted in rat tibia bone marrow. Melt-derived BGs were prepared from a base 45S5 BG (45% SiO2, 24.5% CaO, 24.5% Na2O,6% P2O5 in wt%). Sr-doped glass was prepared using 6 wt% SrO as a substitute for the CaO in 45S5 BG (45S5.6Sr). Twenty Wistar rats were used throughout. Under anesthesia, 45S5 BG particles (300-350 ¦Ìm) were placed inside the medullary compartment of the tibia (control), while 45S5.6Sr BG particles were implanted in the contralateral tibia (experimental). The animals were sacrificed at 30d post-implantation. The tibiae were resected, fixed in formalin solution, radiographed and processed for embedding in methyl-methacrylate resin. Undecalcified ground sections were stained with toluidine blue and analyzed using light microscopy. The percentage of bone-implant contact (affinity index) of the BGs was evaluated quantitatively. Histologically, new lamellar bone had formed along the surface of both 45S5 and 45S5.6Sr BG particles within 4 weeks. At 30 days postimplantation, 45S5 and 45S5.6Sr BGs had almost identical affinity indices (%) (88¡À7 and 87¡À9; p>0.05). These results indicate that 45S5.6Sr BG particles are osteoconductive when implanted inside the intramedullary canal of rat tibiae.Ceramics Division, Res Institute for Materials Science and Technology, Mar del Plata There is accumulating evidence that strontium (Sr) has positive effects on bone formation. Thus, it is reasonable to expect that its presence in biomaterials can enhance the osteoconductivity leading to osseointegration. The aim of the present study was to evaluate the osteoconductivity of Sr-doped bioactive glass (BG) particles implanted in rat tibia bone marrow. Melt-derived BGs were prepared from a base 45S5 BG (45% SiO2, 24.5% CaO, 24.5% Na2O,6% P2O5 in wt%). Sr-doped glass was prepared using 6 wt% SrO as a substitute for the CaO in 45S5 BG (45S5.6Sr). Twenty Wistar rats were used throughout. Under anesthesia, 45S5 BG particles (300-350 ¦Ìm) were placed inside the medullary compartment of the tibia (control), while 45S5.6Sr BG particles were implanted in the contralateral tibia (experimental). The animals were sacrificed at 30d post-implantation. The tibiae were resected, fixed in formalin solution, radiographed and processed for embedding in methyl-methacrylate resin. Undecalcified ground sections were stained with toluidine blue and analyzed using light microscopy. The percentage of bone-implant contact (affinity index) of the BGs was evaluated quantitatively. Histologically, new lamellar bone had formed along the surface of both 45S5 and 45S5.6Sr BG particles within 4 weeks. At 30 days postimplantation, 45S5 and 45S5.6Sr BGs had almost identical affinity indices (%) (88¡À7 and 87¡À9; p>0.05). These results indicate that 45S5.6Sr BG particles are osteoconductive when implanted inside the intramedullary canal of rat tibiae.2, 24.5% CaO, 24.5% Na2O,6% P2O5 in wt%). Sr-doped glass was prepared using 6 wt% SrO as a substitute for the CaO in 45S5 BG (45S5.6Sr). Twenty Wistar rats were used throughout. Under anesthesia, 45S5 BG particles (300-350 ¦Ìm) were placed inside the medullary compartment of the tibia (control), while 45S5.6Sr BG particles were implanted in the contralateral tibia (experimental). The animals were sacrificed at 30d post-implantation. The tibiae were resected, fixed in formalin solution, radiographed and processed for embedding in methyl-methacrylate resin. Undecalcified ground sections were stained with toluidine blue and analyzed using light microscopy. The percentage of bone-implant contact (affinity index) of the BGs was evaluated quantitatively. Histologically, new lamellar bone had formed along the surface of both 45S5 and 45S5.6Sr BG particles within 4 weeks. At 30 days postimplantation, 45S5 and 45S5.6Sr BGs had almost identical affinity indices (%) (88¡À7 and 87¡À9; p>0.05). These results indicate that 45S5.6Sr BG particles are osteoconductive when implanted inside the intramedullary canal of rat tibiae.p>0.05). These results indicate that 45S5.6Sr BG particles are osteoconductive when implanted inside the intramedullary canal of rat tibiae.