Oligodendrocytes are recognised for their capacity to ensheath neuronal axons with tightly packed, multi-layered cell membranes, forming the myelin sheath. This myelin sheath plays a pivotal role as an insulating layer surrounding neuronal axons. It effectively segregates the conductive environments inside and outside neuronal axons, thereby preventing ion leakage and minimising signal loss. The loss of the myelin sheath can lead to physical and mental health issues, including disabilities and depression. Consequently, there is a pressing need for in-vitro models to investigate oligodendrocyte ensheathment behaviour.

Current models often employ engineered nano- or micro-fibres to simulate neuronal axons but frequently lack electrical conductivity. To address this gap, this thesis introduces novel conductive fibres made from Poly(3,4-ethylenedioxythiophene):Poly(Styrene Sulfonate) (PEDOT:PSS). These biocompatible fibres possess electrical conductivity and mechanical stiffness, mimicking the diameter of axons while facilitating electrical stimulation and real-time impedance measurements.

Examination of Scanning Electron Microscopy (SEM) images reveals that oligodendrocytes adhere to these fibres, extend their cell membranes, and ensheath the fibres. Immunofluorescence images further indicate that the oligodendrocyte expresses Myelin Basic Protein (MBP), which is a characteristic of myelinating oligodendrocytes and has the ability to compact multiple cell membrane layers. Additionally, the author has derived an equivalent circuit to interpret device-level impedance results.