title: Photo-induced in situ crosslinking of polymer brushes with dimethyl maleimide moieties for dynamically stimulating stem cell differentiation.
abstract: We designed photo-crosslinkable polymer brushes with dimethylmaleimide moieties, in order to demonstrate dynamic stimulation of cell differentiation in mesenchymal stem cells (MSCs). The polymer brushes were synthesized by surface-initiated reversible addition fragmentation chain transfer polymerization using dimethylmaleimide ethyl methacrylate and methyl methacrylate on a chain transfer agent-immobilized glass surface. The polymer brushes were crosslinked by photodimerization of the dimethylmaleimide moieties within polymer chains with stem cells present on the surface. In order to evaluate the effects of in situ photo-induced crosslinking of the polymer brushes on gene expression of stem cells, human bone marrow MSCs were cultured under static and dynamic culture conditions for 7 days. Expression of the osteocalcin (Ocn) gene in MSCs was used as an indicator of osteoblast differentiation under dynamic culture conditions. Structural conversion from non-crosslinked polymer brushes to crosslinked polymer brushes increased the expression of Ocn by 1.4-fold in the presence of adhered cells, compared with non-crosslinked polymer brushes under static culture conditions. These results suggest that MSCs recognized surface conversion from non-crosslinked to crosslinked structures, which resulted in altered differentiation lineages. Therefore, photo-crosslinkable surfaces with dimethyl maleimide moieties are potential novel materials for dynamically stimulating MSC differentiation.
authors.affiliation: a Department of Life Science and Medical Bioscience , School of Advanced Science and Engineering, Waseda University (TWIns) , Tokyo , Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Arisaka
authors.affiliation: a Department of Life Science and Medical Bioscience , School of Advanced Science and Engineering, Waseda University (TWIns) , Tokyo , Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Nishijima
authors.affiliation: b Department of Materials Science and Chemistry , University of Hyogo , Himeji , Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Yusa
authors.affiliation: a Department of Life Science and Medical Bioscience , School of Advanced Science and Engineering, Waseda University (TWIns) , Tokyo , Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Takeda
mesh_terms: D002448:Cell Adhesion; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D049109:Cell Proliferation; D003432:Cross-Linking Reagents / Q000737:chemistry*; D006801:Humans; D008027:Light; D008301:Maleimides / Q000737:chemistry*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008689:Methacrylates / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods
chemical_list: D003432:Cross-Linking Reagents; D008301:Maleimides; D008689:Methacrylates; D011108:Polymers
keywords: Photo-induced crosslinking; dimethyl maleimide; dynamic differentiation; mesenchymal stem cell; polymer brush