title: Effect of transforming growth factor-beta on osteoblast cells cultured on 3 different hydroxyapatite surfaces.
abstract: In this study, the specific objective was to investigate the combined effect of different treatments of transforming growth factor-beta (TGF-beta) and hydroxyapatite (HA) on osteoblast response in vitro. Since the nature of bone cell responses in vitro is influenced by the properties of HA ceramics, this study was divided into 2 components: a chemical and crystallographic characterization of the HA ceramics, and an in vitro cell culture study. Sintered HA samples were observed to have the highest crystallite size, compared to as-received HA and calcined HA samples. No differences in surface roughness and chemical composition were observed between the sintered, calcined, and as-received HA surfaces. In concurrence with the x-ray diffraction, high-resolution x-ray photoelectron spectroscopy of Ca 2p also indicated a higher crystallinity on sintered HA samples compared to calcined and as-received HA samples. Protein production by osteoblast cells was not statistically different on the 3 HA surfaces in the absence of TGF-beta. However, there was a dose-dependent increase in TGF-beta-stimulated protein production on the 3 different HA surfaces. As indicated by increased alkaline phosphatase-specific activity, as well as 1,25 (OH2) vitamin D3-stimulated osteocalcin production, a more differentiated osteoblastlike phenotype was observed on the sintered HA surfaces compared to the as-received HA and calcined HA surfaces. An increased osteoblast-like cell activity on sintered HA surfaces in the presence of different TGF-beta dosage suggested that sintering of HA surfaces may play an important role in governing cellular response.
authors.affiliation: University of Texas Health Science Center at San Antonio, Department of Restorative Materials 78284, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Ong
authors.forename: D L
authors.initials: DL
authors.lastname: Carnes
authors.forename: A
authors.initials: A
authors.lastname: Sogal
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000704:Analysis of Variance; D002117:Calcitriol / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D017886:Durapatite / Q000737:chemistry*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D006358:Hot Temperature; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D015675:Osteocalcin / Q000096:biosynthesis; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014961:X-Ray Diffraction
chemical_list: D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta; D015675:Osteocalcin; D017886:Durapatite; D000469:Alkaline Phosphatase; D002117:Calcitriol