title: Bioglass 45S5 stimulates osteoblast turnover and enhances bone formation In vitro: implications and applications for bone tissue engineering.
abstract: We investigated the concept of using bioactive substrates as templates for in vitro synthesis of bone tissue for transplantation by assessing the osteogenic potential of a melt-derived bioactive glass ceramic (Bioglass 45S5) in vitro. Bioactive glass ceramic and bioinert (plastic) substrates were seeded with human primary osteoblasts and evaluated after 2, 6, and 12 days. Flow cytometric analysis of the cell cycle suggested that the bioactive glass-ceramic substrate induced osteoblast proliferation, as indicated by increased cell populations in both S (DNA synthesis) and G2/M (mitosis) phases of the cell cycle. Biochemical analysis of the osteoblast differentiation markers alkaline phosphatase (ALP) and osteocalcin indicated that the bioactive glass-ceramic substrate augmented osteoblast commitment and selection of a mature osteoblastic phenotype. Scanning electron microscopic observations of discrete bone nodules over the surface of the bioactive material, from day 6 onward, further supported this notion. A combination of fluorescence, confocal, transmission electron microscopy, and X-ray microprobe (SEM-EDAX) examinations revealed that the nodules were made of cell aggregates which produced mineralized collagenous matrix. Control substrates did not exhibit mineralized nodule formation at any point studied up to 12 days. In conclusion, this study shows that Bioglass 45S5 has the ability to stimulate the growth and osteogenic differentiation of human primary osteoblasts. These findings have potential applications for tissue engineering where this bioactive glass substrate could be used as a template for the formation of bioengineered bone tissue.
authors.affiliation: Department of Histochemistry, Commonwealth Building, Imperial College School of Medicine, Hammersmith Campus, The Hammersmith Hospital, Ducane Rd, London W12 ONN, UK.
authors.forename: I D
authors.initials: ID
authors.lastname: Xynos
authors.forename: M V
authors.initials: MV
authors.lastname: Hukkanen
authors.forename: J J
authors.initials: JJ
authors.lastname: Batten
authors.forename: L D
authors.initials: LD
authors.lastname: Buttery
authors.forename: L L
authors.initials: LL
authors.lastname: Hench
authors.forename: J M
authors.initials: JM
authors.lastname: Polak
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001672:Biocompatible Materials; D001698:Biomedical Engineering / Q000379:methods*; D001846:Bone Development; D001842:Bone and Bones / Q000378:metabolism / Q000648:ultrastructure; D002455:Cell Division; D002478:Cells, Cultured; D002516:Ceramics; D004577:Electron Probe Microanalysis; D005434:Flow Cytometry; D006801:Humans; D008422:Materials Testing; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology*; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology*
chemical_list: D001672:Biocompatible Materials; C022107:Bioglass; D015675:Osteocalcin; D000469:Alkaline Phosphatase