Influence of membrane surface properties on the growth of neuronal cells isolated from hippocampus

Membraneshavebecomeofgreatinterestfortissueengineeringapplication,sincetheyoffertheadvantageof developing neuronal tissue that may be used in implantable orin vitrohybrid systems for the simulationof brain function. The behaviour of neurons isolated from the hippocampus on membranes with differentsurface properties was investigated.The different membranes used as substrates for cell adhesion consisted of polyester (PE), modifiedpolyetheretherketone (PEEK-WC), fluorocarbon (FC) and polyethersulfone (PES), all of which coated withpoly-l-lysine (PLL) in order to have the same functional groups interacting with cells. The membranesexhibited different morphological surface properties in terms of pore size, porosity and roughness.Hippocampal neurons exhibited a different morphology in response to varying the properties of themembrane surface. Indeed, cells grown on the smoother membranes and namely FC and PES membranesdisplayed a large number of neurites with consequent formation of bundles. As a consequence whilea very complex network was formed on these membranes, cells tend to, instead, form aggregates andmost of the processes are developed inside the pores of the membranes when rougher PEEK-WC surfaceswere used. In addition, the secretion of brain-derived neurotrophic factor (BDNF) was expressed at highlevels in neurons grown on FC membranes with respect to the other membranes. Taken together theseresults suggest the pivotal role played by membrane surface properties in the adhesion and growth of thehippocampal neurons, which must be considered in the development of tailored membranes for neuraltissue engineering.