Scaffold-free cell sheet engineering is a promising technique used in tissue engineering to regenerate damaged tissue such as cornea, heart, liver, etc. Typically, cell sheets can be harvested noninvasively by thermo-sensitive poly(N-isopropylacrylamine) immobilized culture dishes when temperature decrease because the surface changes from hydrophobic to hydrophilic. The detached cell sheets form cell-cell junctions and ECM and contain various growth factors. Polyrotaxanes (PRXs) have attracted considerable attention because of their dynamic properties resulting from the molecular mobility of the threaded cyclic molecules along with the axle polymer. Previously, we reported on acetylated PRXs (Ac-PRXs), which are composed of 36% acetylated α-CDs, poly(ethylene glycol) (PEG; Mn=10,000), and adamantyl groups, and their solubility and temperature-responsive properties in aqueous solutions were investigated. Herein, we designed novel Ac-PRX with temperature-responsive properties for cell sheet engineering. It is consisted by 36% acetylated α-CDs and PEG-b-poly(benzyl methacrylate) triblock copolymer. The Ac-PRX immobilized surfaces were successfully prepared. We confirmed that NIH/3T3 cells adhered and proliferated on the Ac-PRX immobilized surface at 37 °C, but the cell sheets were separated from the surface at 10 °C. Therefore, Ac-PRX immobilized surfaces with temperature-responsive properties are considered a new type of material for cell sheet engineering.
This work was supported by the material, parts technology development project (package type) (20013651, Development of an aseptic sterilizer for producing biopharmaceuticals by control pressure 0.01Mpa 1.0 precision based on AL Fuzzy) funded by the Ministry of Trade, industry & Energy (MOTIE, Korea).