Textured Surface of Self-Assembled Particles as a Scaffold for Selective Cell Adhesion and Growth

SiO 2 particles (φ 1 μm) self-assemble into hexagonal arrangements on a glass substrate. Dip-coating is also used to produce linear patterns of particles several tens of micrometers in width on substrates patterned with octadecyltrichlorosilane (OTS). Some particles are coated with specific proteins via electrochemical adsorption and structured on a glass substrate. The upper surfaces of self-assembled particles have specifically-ordered asperities that can be called textures. These textured surfaces are applied to a cell scaffold. PC12 and HeLa cells adhere to the textured surfaces of particles more often than they adhere to flat (smooth) surfaces. The cells are located on approximately 50-μm-width of self-assembled particles. Thus, it is found that the textured surface of particles functions as a template for autonomous cell patterning. An in-situ observation shows that the selective adhesion of cells is achieved by their extensions and migrations from the flat region to the particles. Coating particles with proteins enhances cell adhesiveness in such a way that isolated cells adhere to the linear patterns of particles in straight lines. The textured surfaces of particles also affect cell growth. As cell growth is restricted on the textured surfaces of particles, a confluent state of aggregated cells is achieved on only a linear pattern of particles.