The innovation engine for new materials

Brenda Doherty


Trinity College Dublin




Dr. Xavier Banquy

Faculty Sponsor(s): 

Professor Jacob Israelachvili

Faculty Sponsor's Department: 

Chemical Engineering

Project Title: 

Chasing nanodomains in model myelin membranes

Project Description: 

Demyelination of lipid bilayers comprising the Myelin Sheath results from auto immune diseases such as Multiple Sclerosis, the cause of which is unknown, as is the cure.  The aim of this investigation was to characterise lipid nanodomain variation in fabricated myelin bilayers with the objective to further understand domain role in the demyelination process.  Previous work has indicated strong connection between the varying lipid concentration, and composition, in myelin aqueous layers and bilayer adhesion.  At present there has been relatively little outside focus on lipid domain variation in relation to membrane defects.  In this experiment lipid bilayers were deposited by Langmuir-Blodgett Technique on mica substrate in an attempt to more accurately model myelin bilayers on an axon.  The concentration of the outer lipid leaflet varied as one of Control Cytoplasmic (CYT) / extracellular (EXT) or Experimental Allergic Encephalomyelitis (EAE) CYT / EXT, as desired.  Domains were imaged using Fluorescence and Atomic Microscopy with Texas Red fluorescent marker.  Larger domains were evident in EXT samples with greater density of liquid-ordered phase (Lo) in the sequence: EAE EXT > control EXT > EAE CYT > control CYT.  Domains displayed enhanced size and distribution uniformity in control samples compared to diseased EAE where phase transition was particularly evident in EXT images.  Domains within domains were frequently encountered in EAE samples - the significance of which is still under investigation.  Further data acquisition along with imaging of timed domain evolution is required in this study in addition to observation of domain behaviour under applied potential (mimicking nerve signal conduction).  We anticipate a correlation between signal transfer efficiency and bilayer domain variation.  Evidence of such a relationship could contribute to progress in demyelination retardation or repair in affected biological membranes.