Interactions between titanium dioxide and phosphatidyl serine-containing liposomes: formation and patterning of supported phospholipid bilayers on the surface of a medically relevant material.

Titanium is widely used in biomedical applications. Its mechanical properties and biocompatibility, conferred by a layer of oxide present on its surface, make titanium the material of choice for various implants (artificial hip and knee joints, dental prosthetics, vascular stents, heart valves). Furthermore, the high refractive index of titanium oxide is advantageous in biosensor applications based on optical detection methods. In both of the above fields of application, novel surface modification strategies leading to biointeractive interfaces (that trigger specific responses in biological systems) are continuously sought. In this report, we investigate the interactions between TiO2 and phosphatidyl serine-containing liposomes, present a novel approach for preparing supported phospholipid bilayers (SPBs) of various compositions on TiO2, and use the unique ability of liposomes to distinguish between different surfaces to create SPB corrals on SiO2/TiO2 structured substrates. These results represent an important first step toward the design of biointeractive interfaces on titanium oxide surfaces that are based on a cell membrane-like environment.