Differentiation of induced pluripotent stem cells toward neurons in hydrogel biomaterials.

Regeneration of nerve tissue is one of the most significant challenges in contemporary surgical therapy for nervous system injury. This study presents the neuronal differentiation of induced pluripotent stem (iPS) cells in hydrogels comprising alginate and poly(γ-glutamic acid) (γ-PGA) with surface neuron growth factor (NGF). Differentiating iPS cells in NGF-grafted alginate/γ-PGA constructs were identified by immunochemical staining of anti-SSEA-1 and anti-β III tubulin. The results revealed that the pore diameter of hydrogels increased with an increasing weight ratio of alginate to γ-PGA. The porosity slightly decreased with an increasing weight ratio of alginate to hydrogel. In addition, an increase in the weight ratio of alginate to hydrogel raised the swelling ratio. Morphological images of differentiating iPS cells in NGF-grafted alginate/γ-PGA constructs exhibited neuronal characteristics. The surface NGF enhanced the intensity of β III tubulin and inhibited the intensity of SSEA-1 expressed by differentiating iPS cells in cultured constructs, indicating the differentiation of iPS cells toward neurons. NGF-grafted alginate/γ-PGA hydrogels can be efficient biomaterials in the production of neurons from iPS cells for animal study and preclinical trial.