Detachment of cells adhered on the photoreactive phospholipid polymer surface by photoirradiation and their functionality

Regulating the detachment of adhered living cells from a surface is a key technological requirement to obtain specific cells in the field of cellular engineering. Here, we describe dynamic control of cell adhesion and detachment at a photoreactive and cytocompatible phospholipid polymer surface. The surface was prepared using the amphiphilic and water-insoluble substance poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) bearing 4-[4-(1-hydroxyethyl)-2-methoxy-5-nitrophenoxy]butyric acid (PL) groups in its side chain (PMB-PL). On this prepared surface, the photoinduced control of human epidermoid carcinoma cancer cells (A431 cells) and primary murine embryonic fibroblast (PMEF) cells was examined. The PMB-PL surface allowed successful control of living cells adhesion with photoreactivity. The efficiency of cell detachment obtained was approximately 50% of the initial number of adhered cells. The PL groups at the surface provide adhesion points for cells, as evidenced by the fact that after photoreaction of PL groups by photoirradiation, the number of adhered cells on the surface considerably decreased. Additionally, when the polymer surface was re-used after the first photoirradiation, cells did not adhere to it, and low detachment was observed. The functionalities of the cells detached by photoreaction were evaluated. The proliferation rate and morphological changes of cells were as the same as those of cells detached by conventional enzymatic digestion. Moreover, the extracellular expression levels of transmembrane proteins on cells detached by photoirradiation showed no significant difference with those seen on normal cells. From these results, we conclude that the PMB-PL surface is a suitable platform to regulate cell adhesion and detachment via photochemical reaction.