Membrane bio-hybrid systems: A valuable tool for the study of neuronal activities

At present a great deal of attention is being directed towards the possibility of replacing or restoring the anatomical structural organization of damaged neuronal regions and consequently their functional capacities by developing artificial systems based on biomaterials, scaffolds and cells. Among the biomaterials applied in the field of neurobiotechnology, polymeric semipermeable membranes could provide the mechanical support required for the regulation of cell growth in bio-hybrid systems. The ultimate goal of this technique might be very well achieved by appropriate bio-interactions of desired cell responses (i.e. in vitro induction of a neural circuit, in vivo fabrication of a tissue structure). The great impact of membrane bio-hybrid systems in tissue engineering has allowed the designing of a physiological model such as neuronal elements. These may turn out to be a key approach for studying pathogenic states as well as, and more important, the development of appropriate bio-molecules for therapeutic purposes. In view of the widespread structural organization of all the brain regions, it is the aim of this study to focus our attention on the potential value of this biotechnological approach to a functionally key region such as the hippocampus. Indeed, the principal neurons of this brain region, i.e. pyramidal cells, are actively involved in many hippocampal-dependent neurophysiological functions, such as memory and learning. This makes them a valuable tool to investigate not only their synaptic plasticity properties, but also neurodegenerative events through the distribution and quantification of microtubule-associated protein type 2. In this work, the reconstruction of membrane bio-hybrid systems, constituted of isolated cells and membranes, appears to represent a crucial step for the success of these systems. Moreover, the optimization of transport, physico-chemical and structural properties of the membrane as well as fluid dynamics of cellular microenvironments tend to favor cell-membrane interactions and the functional maintenance of hippocampal cells. As a consequence the feasibility of developing a hippocampal cell membrane bio-hybrid system capable of regenerating a neuronal network could prove to be an important approach for studying the behavior of neuronal populations in some of most common neurodegenerative disease such as Alzheimer's disease.