Thin‐layer photodegradable polyrotaxane gel‐immobilized surfaces for photoregulation of surface properties and cell adhesiveness.

Thin‐layer photodegradable polyrotaxane (PRX) gel‐immobilized surfaces were fabricated to investigate the photoregulation of surface properties. Photodegradable PRXs comprising α‐cyclodextrin as a cyclic molecule, poly(ethylene glycol) as a polymer axel, and bulky trithiocarbonate as a photolabile stopper molecule (PRX‐MTP) were utilized for the fabrication of thin‐layer gels. PRX‐MTP gels were prepared on the surface of the glasses, where the surfaces were treated with an isocyanate group‐containing silane coupling agent to allow the covalent immobilization of the PRX‐MTP gels. This PRX‐MTP gel layer was disappeared upon irradiation with ultraviolet (UV; 365 nm) or visible light (465 nm) for 2 h due to the photodegradation of PRX‐MTPs. The surface wettability and roughness were changed owing to the photodegradation of the PRX‐MTP gel layer. When cells were seeded on the PRX‐MTP gel surfaces, adhesion was not observed. However, visible light irradiation of the PRX‐MTP gel layer resulted in cell adhesion on the irradiated surfaces. Consequently, it was determined that the surface properties and cell adhesiveness of the PRX‐MTP gel surfaces could be regulated by visible light irradiation. The photodegradable PRX‐MTP gel surfaces could be utilized for research on cell patterning, cell function control, and advanced cell culture system. [ABSTRACT FROM AUTHOR]