title: Effects of strontium-doped bioactive glass on the differentiation of cultured osteogenic cells.
abstract: There is accumulating evidence that strontium-containing biomaterials have positive effects on bone tissue repair. We investigated the in vitro effect of a new Sr-doped bioactive glass manufactured by the sol-gel method on osteoblast viability and differentiation. Osteoblasts isolated from foetal mouse calvaria were cultured in the presence of bioactive glass particles; particles were undoped (B75) or Sr-doped with 1 wt.% (B75-Sr1) and 5 wt.% (B75-Sr5). Morphological analysis was carried out by contrast-phase microscopy and scanning electron microscopy (SEM). Cell viability was evaluated by the MTS assay at 24 h, 48 h and 72 h. At 24 h, day 6 and day 12, osteoblast differentiation was evaluated by assaying alkaline phosphatase (ALP) activity, osteocalcin (OC) secretion and gene expression of various bone markers, using Real-Time-PCR. Alizarin Red staining and ALP histoenzymatic localisation were performed on day 12. Microscopic observations and MTS showed an absence of cytotoxicity in the three investigated bioactive glasses. B75-Sr5 particles in cell cultures, in comparison with those of B75 and B75-Sr1, resulted in a significant up-regulation of Runx2, Osterix, Dlx5, collagen I, ALP, bone sialoprotein (BSP) and OC mRNA levels on day 12, which was associated with an increase of ALP activity on day 6 and OC secretion on day 12. In conclusion, osteoblast differentiation of foetal mouse calvarial cells was enhanced in the presence of bioactive glass particles containing 5 wt.% strontium. Thus, B75-Sr5 may represent a promising bone-grafting material for bone regeneration procedures.
authors.affiliation: Laboratoire de Physiopathologie Orale et Moléculaire, Centre de Recherche des Cordeliers, INSERM, UMRS 872, Equipe 5, 15-21 Rue de l'Ecole de Médecine, F-75270 Paris Cedex 06, France. isaacjuliane@yahoo.fr
authors.forename: J
authors.initials: J
authors.lastname: Isaac
authors.forename: J
authors.initials: J
authors.lastname: Nohra
authors.forename: J
authors.initials: J
authors.lastname: Lao
authors.forename: E
authors.initials: E
authors.lastname: Jallot
authors.forename: J M
authors.initials: JM
authors.lastname: Nedelec
authors.forename: A
authors.initials: A
authors.lastname: Berdal
authors.forename: J M
authors.initials: JM
authors.lastname: Sautier
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D001483:Base Sequence; D001672:Biocompatible Materials; D015415:Biomarkers; D001861:Bone Regeneration; D001842:Bone and Bones / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D015870:Gene Expression; D005898:Glass; D051379:Mice; D008853:Microscopy; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012886:Skull / Q000166:cytology / Q000196:embryology; D013324:Strontium
chemical_list: D001672:Biocompatible Materials; D015415:Biomarkers; D012333:RNA, Messenger; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D013324:Strontium