Culture of mouse embryonic stem cells on photoimmobilized polymers

Mouse embryonic stem (ES) cells were cultured on four types of polymer with different surface properties. The polymers were poly(acrylic acid), polyallylamine, gelatin, and poly(2-methacryloyloxyethyl phosphorylcholine-co-methacrylic acid) (PMAc50), and were coupled with azidophenyl groups and photoimmobilized on conventional polystyrene cell-culture dishes. Mouse ES cells were cultured on the immobilized polymer surfaces, and cell morphology, cell growth, staining for alkaline phosphatase, activation of the transcription factor stat3, and expression of the octamer-binding protein 3/4 (Oct3/4) transcription factor and the zinc finger-containing transcription factor (GATA4) were observed. Morphology and growth rate were significantly affected by the polymer surface properties. The ES cells attached to gelatin or polyallylamine surfaces; however, colonies formed on the former but not the latter. In addition, significant enhancement of growth was observed on the gelatin surface. In contrast, ES cells aggregated to form an embryoid body on the photoimmobilized poly(acrylic acid) surface and the PMAc50 surface, although cell growth was reduced. Significant enhancement of aggregation of ES cells on the PMAc50 surface was observed in morphology and gene expression analyses.