title: Titanium phosphate glass microcarriers induce enhanced osteogenic cell proliferation and human mesenchymal stem cell protein expression.
abstract: In this study, we have developed 50- to 100-µm-sized titanium phosphate glass microcarriers (denoted as Ti5) that show enhanced proliferation of human mesenchymal stem cells and MG63 osteosarcoma cells, as well as enhanced human mesenchymal stem cell expression of bone differentiation markers, in comparison with commercially available glass microspheres at all time points. We also demonstrate that these microcarriers provide superior human mesenchymal stem cell proliferation with conventional Dulbecco's Modified Eagle medium than with a specially developed commercial stem cell medium. The microcarrier proliferative capacity is revealed by a 24-fold increase in MG63 cell numbers in spinner flask bioreactor studies performed over a 7-day period, versus only a 6-fold increase in control microspheres under the same conditions; the corresponding values of Ti5 and control microspheres under static culture are 8-fold and 7-fold, respectively. The capability of guided osteogenic differentiation is confirmed by ELISAs for bone morphogenetic protein-2 and osteopontin, which reveal significantly greater expression of these markers, especially osteopontin, by human mesenchymal stem cells on the Ti5 microspheres than on the control. Scanning electron microscopy and confocal laser scanning microscopy images reveal favorable MG63 and human mesenchymal stem cell adhesion on the Ti5 microsphere surfaces. Thus, the results demonstrate the suitability of the developed microspheres for use as microcarriers in bone tissue engineering applications.
authors.affiliation: Department of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK.
authors.forename: Nilay J
authors.initials: NJ
authors.lastname: Lakhkar
authors.affiliation: UCL Division of Medicine, University College London, London, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: M Day
authors.affiliation: Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, Republic of Korea ; Institute of Tissue Regeneration Engineering, Dankook University, Cheonan, Republic of Korea ; Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
authors.forename: Hae-Won
authors.initials: HW
authors.lastname: Kim
authors.affiliation: UCL Medical School, University College London, London, UK.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Ludka
authors.affiliation: Department of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK.
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Mordan
authors.affiliation: Department of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK ; Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: Vehid
authors.initials: V
authors.lastname: Salih
authors.affiliation: Department of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK ; Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, Republic of Korea.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Knowles
keywords: Titanium; bone cells; mesenchymal stem cells; microspheres; phosphate glasses