Immunostaining results from F3-effluc cells encapsulated within the hydrogel matrix. (a) Hematoxylin and eosin staining on day 21 showed a homogenous distribution in the cell-only group (left upper panel). A small quantity of the host cells was infiltrated into each hydrogel (upper middle and right panel). A partially colonized cell mass (lower two panels) in the hydrogel was found in the soft GPT 1.8 K and the stiff GPT 5.8 K groups. (b) Each section acquired from the resected cell mass was stained using different antibodies. The proliferated F3-effluc cells from all groups did not show any Tuj1 (early neuronal marker) expression. In contrast, implanted cells within the hydrogels were highly stained (red color) with the proliferative marker, Ki-67, compared to the cell-only group. The nucleus was counterstained with DAPI (blue color).