Neural interfacing biomaterials coated with the firmly tethered neuro-specific lipid bilayer

Abstract

The limitation of short-term usage of neural interfacing devices encouraged the development of neuro-specific biomaterials. Our hypothesis is that a biomaterial covered with the neuronal cell-derived membrane possess-ing neural cell adhesion molecule (L1CAM) can promote neuronal adhesion and activation and minimize im-mune responses at the condition of neural implantation. To demonstrate the hypothesis, we prepared the titanium surface-modified with a PC12 cell membrane-derived lipid bilayer, covalently tethered on the surface (PM-TLB). Anti-fouling studies informed us that PM-TLB was sufficiently resistant to the fouling of plasma proteins as well as the adhesion of blood components and bacteria. Cell studies demonstrated that PM-TLB is specific to neuronal cells and non-specific to astrocytes and macrophages, clearly shown in a normal condition and an inflammatory condition. The neuronal activation study supported that PM-TLB improves the outgrowth of neurites and activation stages more than the poly(L-lysine) polymer, which is the most used substrate for neuronal cells. These results conclude that PM-TLB is an efficient surface modification showing selective mod-ulation against neurons and the immune system, promoting neuronal interaction and suppressing neuro-inflammatory responses for applications to neuro-implantable devices.