Boosting the Cell Harvesting Performance of Poly(di(ethylene glycol)methyl ether methacrylate) Cell Release Layers via Copolymerization of Photo- and Thermoresponsive Monomers.

The performance of the cell-selective thermoresponsive poly(di(ethylene glycol)methyl ether methacrylate) (PDEGMA) cell harvest system is shown to be drastically enhanced by exploiting the combination of photoresponsive spiropyran derivates and PDEGMA in copolymerized brushes. The analysis of copolymerized 1'-(2-methacryloxyethyl)-3',3'-dimethyl-6-nitrospiro(2H-1-benzopyran-2,2'-indoline) (SPMA) (DEMGA) di(ethylene glycol)methyl ether methacrylate brushes revealed that a minor adjustment of the SPMA/DEGMA ratios results in a significant alternation of wettability as well as protein adsorption, when switching the temperature from 37 to 22 °C and alternately irradiating using different light wavelengths (from 530 to 365 nm). Thin P(SPMA-co-DEGMA) layers supported pancreatic tumor PaTu 8988t cells with high cell viability. Copolymer layers with 2.5% SPMA/DEGMA led to the highest efficiency of enzyme-free cell release with very good cell viability. The release is induced by cooling the cell culture medium to 22 °C and irradiating the surface with 365 nm light. Compared to neat PDEGMA, the P(SPMA-co-DEGMA) layers showed a threefold increase in the speed of the change of cell morphology of the attached cells and a >5 times increased fraction of detached cells, which underlines the potential of these dual responsive PDEGMA systems for optimized performance in the facile capture, culture, and release of different cell lines.