title: The osteogenic response of mesenchymal stromal cells to strontium-substituted bioactive glasses.
abstract: Bioactive glasses are known to stimulate bone healing, and the incorporation of strontium has the potential to increase their potency. In this study, calcium oxide in the 45S5 bioactive glass composition was partially (50%, Sr50) or fully (100%, Sr100) substituted with strontium oxide on a molar basis. The effects of the substitution on bioactive glass properties were studied, including density, solubility, and in vitro cytotoxicity. Stimulation of osteogenic differentiation was investigated using mesenchymal stromal cells obtained from rat bone marrow. Strontium substitution resulted in altered physical properties including increased solubility. Statistically significant reductions in cell viability were observed with the addition of bioactive glass powders to culture medium. Specifically, addition of ≥ 13.3 mg/ml of 45S5 bioactive glass or Sr50, or ≥ 6.7 mg/ml of Sr100, resulted in significant inhibition. Real-time PCR analyses detected the upregulation of genes associated with osteoblastic differentiation in the presence of all bioactive glass compositions. Some genes, including Alpl and Bglap, were further stimulated in the presence of Sr50 and Sr100. It was concluded that strontium-substituted bioactive glasses promoted osteogenesis in a differentiating bone cell culture model and, therefore, have considerable potential for use as improved bioactive glasses for bone tissue regeneration.
authors.affiliation: School of Clinical Dentistry, University of Sheffield, UK.
authors.forename: Martin E
authors.initials: ME
authors.lastname: Santocildes-Romero
authors.forename: Aileen
authors.initials: A
authors.lastname: Crawford
authors.forename: Paul V
authors.initials: PV
authors.lastname: Hatton
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Goodchild
authors.forename: Ian M
authors.initials: IM
authors.lastname: Reaney
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Miller
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000473:pathology; D017610:Calcium Compounds / Q000737:chemistry; D002454:Cell Differentiation; D002470:Cell Survival; D002516:Ceramics / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis / Q000502:physiology*; D010087:Oxides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D012038:Regeneration; D044968:Regenerative Medicine / Q000379:methods; D012995:Solubility; D013324:Strontium / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D017610:Calcium Compounds; D010087:Oxides; C425330:bioactive glass 45S5; C016538:lime; D010100:Oxygen; D013324:Strontium
keywords: bioactive glass; mesenchymal stromal cells; osteogenic differentiation; real-time PCR; strontium