title: Control over the gradient differentiation of rat BMSCs on a PCL membrane with surface-immobilized alendronate gradient.
abstract: Gradient biomaterials can offer progressively changing signals to specific tissue interface, and thereby modulate the conjunction between different tissues. A linear density gradient of alendronate (Aln), a molecule that is capable of promoting osteogenic differentiation of bone mesenchymal stem cells (BMSCs), was created on an aminolyzed poly(ε-caprolactone) (PCL) membrane. X-ray photoelectron spectroscopy and quartz crystal microbalance with dissipation revealed the linear increase of the Aln amount as a function of the position on the PCL membrane. By contrast, the surface wettability and energy were kept unchanged. The surface-grafted Aln showed a stronger ability to induce the osteogenic differentiation of rat BMSCs than its counterpart in culture medium of the same amount, and the osteo-inductive culture medium. On the Aln-grafted gradient surface, the BMSCs showed gradient osteogenic differentiation as a function of membrane position in terms of cell morphology, alkaline phosphatase activity, calcium deposition, and the expression of osteogenesis marker proteins including collagen type I (COL I), Runt-related transcription factor 2 (Runx2), and osteocalcin (OCN).
authors.affiliation: MOE of Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhu
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Mao
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
mesh_terms: D019386:Alendronate / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D002118:Calcium / Q000737:chemistry; D002448:Cell Adhesion; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D015675:Osteocalcin / Q000096:biosynthesis; D010012:Osteogenesis / Q000187:drug effects*; D056951:Photoelectron Spectroscopy; D011091:Polyesters / Q000737:chemistry; D051381:Rats
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D011091:Polyesters; C493717:Runx2 protein, rat; D015675:Osteocalcin; C016240:polycaprolactone; D000469:Alkaline Phosphatase; D002118:Calcium; D019386:Alendronate