Optimising 3D scaffold for otic neural progenitor differentiation

Hearing loss is a condition highly prevalent worldwide. It affects people of a broad age range since the causes and risk factors are varied. At present, some types of hearing impairments have a palliative treatment whereas some, especially for those where otic neurons are damaged, cannot be properly treated. Recent findings had shown it possible to use human embryonic stem cell-derived otic neural progenitors (ONPs) as a new mode of treating hearing loss caused by damage to the spiral ganglion neurons (SGNs). To improve the efficiency and overcome some limitations of this potential treatment, we have applied principles of tissue engineering which involves an interaction between cells and an extracellular matrix -mimicking scaffold. Here, we describe the influence of poly(l-lactic acid)(PLLA) aligned fibres on ONP cell morphology, proliferation, neuronal differentiation and establishment of neural polarity under both progenitor and neuralising conditions. The results show that most of ONPs on aligned fibres exhibited bipolar morphology and extended their neurites along the major fibre axis. Their proliferation was lower than those in 2D culture but the differentiation of ONPs on aligned fibres was significantly enhanced in both progenitor and neuralising conditions as indicated by the fluorescence intensity and number of cells that were positive for neuronal markers ({beta}-tubulin III and NF200) and the expression pattern of spiral ganglion molecular markers (MMP13, NPR2 and NTNG1). Moreover, axonal and dendritic markers (TAU and MAP2 respectively) were also induced after 14 days in culture.