Potential of Gene and Cell Therapy for Inner Ear Hair Cells

Figure 2

Differentiation of the inner ear organoid over time. The morphology and differentiation patterns of stem cells at different stages over time are shown. Differentiation is divided into three phases (maintenance, differentiation, and maturation) and can be followed by epifluorescence microscopy. The hanging drop technique was used for embryonic body (EB) formation. In the differentiation phase, BPM4 and TGFβi are administered on day 2 to induce nonneurodermal ectoderm as well as FGF2 and BPM4i on day 3 to induce preplacodal ectoderm. Day 6 marks the beginning of the maturation phase. The cells were fixed for microscopic analysis on day 18, at which time formation of the organoid structure was observed. These organoids contain several Myo7a-positive cells. ESCs, embryonic stem cells; EB embryonic body; DE, definitive ectoderm; OEPD, otic-epibranchial placode domain. White scale bars are 20 um. Black scale bars are 250 um.