title: In vitro response of human osteoblasts to multi-step sol-gel derived bioactive glass nanoparticles for bone tissue engineering.
abstract: A multi-step sol-gel process was employed to synthesize bioactive glass (BG) nanoparticles. Transmission electron microscopy (TEM) revealed that the BG nanoparticles were spherical and ranged from 30 to 60 nm in diameter. In vitro reactivity of the BG nanoparticles was tested in phosphate buffer saline (PBS), Tris-buffer (TRIS), simulated body fluid (SBF), and Dulbecco's modified Eagle's medium (DMEM), in comparison with similar sized hydroxyapatite (HA) and silicon substituted HA (SiHA) nanoparticles. Bioactivity of the BG nanoparticles was confirmed through Fourier transform infrared spectroscopy (FTIR) analysis. It was found that bone-like apatite was formed after immersion in SBF at 7 days. Solutions containing BG nanoparticles were slightly more alkaline than HA and SiHA, suggesting that a more rapid apatite formation on BG was related to solution-mediated dissolution. Primary human osteoblast (HOB) cell model was used to evaluate biological responses to BG nanoparticles. Lactate dehydrogenase (LDH) cytotoxicity assay showed that HOB cells were not adversely affected by the BG nanoparticles throughout the 7day test period. Interestingly, MTS assay results showed an enhancement in cell proliferation in the presence of BG when compared to HA and SiHA nanoparticles. Particularly, statistically significant (p<0.05) alkaline phosphatase (ALP) activity of HOB cells was found on the culture containing BG nanoparticles, suggesting that the cell differentiation might be promoted by BG. Real-time quantitative PCR analysis (qPCR) further confirmed this finding, as a significantly higher level of RUNX2 gene expression was recorded on the cells cultured in the presence of BG nanoparticles when compared to those with HA and SiHA.
authors.affiliation: Department of Mechanical Engineering, University College London, London WC1E 7JE, UK. Electronic address: jian.fan@ucl.ac.uk.
authors.forename: Jian Ping
authors.initials: JP
authors.lastname: Fan
authors.affiliation: Biomaterials, Tissue Engineering & Imaging, The Dental Institute, King's College London, Guy's Hospital, London SE1 9BT, UK.
authors.forename: Priya
authors.initials: P
authors.lastname: Kalia
authors.affiliation: Biomaterials, Tissue Engineering & Imaging, The Dental Institute, King's College London, Guy's Hospital, London SE1 9BT, UK.
authors.forename: Lucy
authors.initials: L
authors.lastname: Di Silvio
authors.affiliation: Department of Mechanical Engineering, University College London, London WC1E 7JE, UK.
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001842:Bone and Bones / Q000502:physiology*; D016923:Cell Death; D049109:Cell Proliferation; D048430:Cell Shape; D017886:Durapatite / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010006:Osteoblasts / Q000166:cytology* / Q000201:enzymology / Q000648:ultrastructure; D010012:Osteogenesis; D010316:Particle Size; D044367:Phase Transition; D060888:Real-Time Polymerase Chain Reaction; D012825:Silicon / Q000737:chemistry; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D023822:Tissue Engineering / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D012996:Solutions; D017886:Durapatite; D000469:Alkaline Phosphatase; D012825:Silicon
keywords: Bioactive glass; Hydroxyapatite; Nanoparticles; Osteoblast; Sol–gel; Tissue engineering