title: Gene-modified cell detachment on photoresponsive hydrogels strengthened through hydrogen bonding.
abstract: Photoresponsive hydrogels are potentially useful as drug delivery and cell culture media, but there has been no report on manipulation of cell attachment/detachment and gene transfection simultaneously on the surface of this single gel. In the present study, strong light sensitive hydrogels were prepared mechanically by photoinitiated copolymerization of spiropyran-containing monomer, 2-vinyl-4,6-diamino-1,3,5-triazine, hydrogen bonding monomer, oligo(ethylene glycol) methacrylate and polyethylene glycol diacrylate (PEGDA, Mn=575). The multiple hydrogen bondings of diaminotriazine residues could contribute to the increase in compressive strengths of the photosensitive hydrogels up to 5.1MPa. UV (365nm) irradiation led to detachment of adhered cells as a result of the increased surface hydrophilicity caused by a switch from hydrophobic spiropyran to hydrophilic merocyanine form. Furthermore, selective detachment of cells could also be achieved by UV light illumination on the specified gel surface. Hydrogen bonding between diaminotriazines were shown to tightly anchor the PVDT/pDNA complex particles on the gel surface, where reverse gene transfection was achieved. Following up with UV irradiation triggered the unharmful detachment of gene-modified cells from the gel surface. It is envisioned that this photosensitive hydrogel holds potential as a versatile platform for operating gene delivery and controlled harvest of desired cells for tissue engineering.
authors.affiliation: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Sun
authors.affiliation: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China.
authors.forename: Pengyan
authors.initials: P
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072, China. Electronic address: wgliu@tju.edu.cn.
authors.forename: Wenguang
authors.initials: W
authors.lastname: Liu
mesh_terms: D002448:Cell Adhesion; D020100:Hydrogels; D006860:Hydrogen Bonding; D013056:Spectrophotometry, Ultraviolet
chemical_list: D020100:Hydrogels
keywords: Cell detachment; Diaminotriazine; Hydrogel; Reverse gene transfection; Spiropyran