title: Synergistic influence of collagen I and BMP 2 drives osteogenic differentiation of mesenchymal stem cells: A cell microarray analysis.
abstract: Cell microarrays are a novel platform for the high throughput discovery of new biomaterials. By re-creating a multitude of cell microenvironments on a single slide, this approach can identify the optimal surface composition to drive a desired cell response. To systematically study the effects of molecular microenvironments on stem cell fate, we designed a cell microarray based on parallel exposure of mesenchymal stem cells (MSCs) to surface-immobilised collagen I (Coll I) and bone morphogenetic protein 2 (BMP 2). This was achieved by means of a reactive coating on a slide surface, enabling the covalent anchoring of Coll I and BMP 2 as microscale spots printed by a robotic contact printer. The surface between the printed protein spots was passivated using poly (ethylene glycol) bisamine 10,000Da (A-PEG). MSCs were then captured and cultured on array spots composed of binary mixtures of Coll I and BMP 2, followed by automated image acquisition and quantitative, multi-parameter analysis of cellular responses. Surface compositions that gave the highest osteogenic differentiation were determined using Runx2 expression and calcium deposition. Quantitative single cell analysis revealed subtle concentration-dependent effects of surface-immobilised proteins on the extent of osteogenic differentiation obscured using conventional analysis. In particular, the synergistic interaction of Coll I and BMP 2 in supporting osteogenic differentiation was confirmed. Our studies demonstrate the value of cell microarray platforms to decipher the combinatorial interactions at play in stem cell niche microenvironments.
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Mawson Institute, University of South Australia, South Australia, Australia. Electronic address: soraya.rasi_ghaemi@mymail.unisa.edu.au.
authors.forename: Soraya
authors.initials: S
authors.lastname: Rasi Ghaemi
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Mawson Institute, University of South Australia, South Australia, Australia. Electronic address: Bahman.Delalat@unisa.edu.au.
authors.forename: Bahman
authors.initials: B
authors.lastname: Delalat
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Mawson Institute, University of South Australia, South Australia, Australia. Electronic address: Xavier.CetoAlseda@unisa.edu.au.
authors.forename: Xavier
authors.initials: X
authors.lastname: Cetó
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Mawson Institute, University of South Australia, South Australia, Australia. Electronic address: Fran.Harding@unisa.edu.au.
authors.forename: Frances J
authors.initials: FJ
authors.lastname: Harding
authors.affiliation: School of Mathematical Sciences, University of Adelaide, South Australia, Australia. Electronic address: simon.tuke@adelaide.edu.au.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Tuke
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Mawson Institute, University of South Australia, South Australia, Australia. Electronic address: Nico.Voelcker@unisa.edu.au.
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Voelcker
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000494:pharmacology*; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D046228:Microarray Analysis / Q000379:methods*; D010012:Osteogenesis / Q000187:drug effects*; D025341:Principal Component Analysis; D040081:Protein Array Analysis; D017208:Rats, Wistar; D018629:Spectrometry, Mass, Secondary Ion
chemical_list: D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; C020243:calcium phosphate
keywords: Bone morphogenetic protein 2; Collagen I; High throughput screening; MSC differentiation; Osteogenesis