title: Glass reinforced hydroxyapatite for hard tissue surgery--part II: in vitro evaluation of bone cell growth and function.
abstract: Hydroxyapatite (HA)-based materials are considered to be potentially useful as bone implant materials, particularly those reinforced with glass to improve mechanical strength. However, the precise effects of glass-reinforced HA on the growth and functions of bone cells are still unclear. The present study has therefore examined the response of human osteoblast-like cells to HA and HA reinforced with two different proportions of glass, namely 2.5% and 5%. All materials enabled the cells to attach and proliferate during 7 days in culture and, although the growth was less than on control plastic surfaces, there was no deleterious effect of the 5% glass composite compared with HA alone. Flow cytometry analysis showed that there was no effect on cell size and granularity, but there were marked and highly selective changes in the expression of certain connective tissue proteins. Thus, while bone sialoprotein and osteonectin were down-regulated on HA alone, the expression of these antigens was relatively enhanced on the composite materials, and collagen type I was also up-regulated on the glass-reinforced HA. Thus, modulation of the glass composition of HA materials could be used to produce not only improved mechanical strength, but also enhanced biocompatibility.
authors.affiliation: Department of Biomaterials, Eastman Dental Institute, University College London, UK.
authors.forename: V
authors.initials: V
authors.lastname: Salih
authors.forename: G
authors.initials: G
authors.lastname: Georgiou
authors.forename: J C
authors.initials: JC
authors.lastname: Knowles
authors.forename: I
authors.initials: I
authors.lastname: Olsen
mesh_terms: D001672:Biocompatible Materials; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism / Q000601:surgery*; D002455:Cell Division; D048429:Cell Size; D017886:Durapatite; D005434:Flow Cytometry; D005898:Glass; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D015676:Osteonectin / Q000378:metabolism; D012795:Sialoglycoproteins / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D015676:Osteonectin; D012795:Sialoglycoproteins; D017886:Durapatite