Robust MeO2MA/vinyl-4,6-diamino-1,3,5-triazine copolymer hydrogels-mediated reverse gene transfection and thermo-induced cell detachment

We have fabricated a robust temperature sensitive hydrogel by photoinitiated copolymerization of 2-(2-methoxyethoxy)ethyl methacrylate (MeO(2)MA), 2-vinyl-4,6-diamino-1,3,5-triazine (VDT) and crosslinker polyethylene glycol diacrylate (PEGDA). It was shown that self-hydrogen bonding; of VDT moieties in the bulk considerably strengthened the mechanical properties of gels, which was dependent on the weight ratio of MeO2/VDT and the initial monomer concentration; the VDT motifs on the surface could efficiently bind DNA for reverse gene transfection. On this soft-wet platform, gene expression lasted 7 days and the re-treated gels could be reused for new cycle of transfection. The gene modified cells could be detached by thermo-triggered switchable surface hydrophilicity of PMEO(2)MA in hydrogel. MU assay showed low cytotoxicity of hydrogels. The results suggested that this type of mechanically strong H-bonded and thermoresponsive hydrogels hold a great potential as an integrated functional soft-wet platform for the unharmful harvest of gene modified seed cells for tissue engineering or as implantable scaffold for gene therapy and regenerative medicine applications. (C) 2010 Elsevier Ltd. All rights reserved.