Topographical control of human neutrophil motility on micropatterned materials with various surface chemistry

Abstract

This chapter discusses topographical control of human neutrophil motility on micropatterned materials with various surface chemistry. Controlling cell responses to an implantable material is essential to tissue engineering. Both chemical and topographical properties of a material surface can play a crucial role because the surface is in direct contact with cells. The migratory behavior of live human neutrophils on the patterned surfaces is observed using a light microscope with transmitted light source. The height and the repeat spacing of the ridges are systematically changed to investigate the effect of microgeometry on neutrophil migration. Moreover, the effect of surface chemistry on neutrophil migration is studied by deposition of a thin layer of “inert”, biocompatible metal such as Au–Pd alloy and titanium on patterned substrates. More than 95% of neutrophils moved in the direction of the long axis of ridges/grooves regardless of the topographical geometry and chemistry, consistent with a phenomenon termed “contact guidance.” The rate of cell movement is strongly dependent on the topographical microgeometry of the ridges. The Au–Pd coating can not change neutrophil migratory behavior on patterned surfaces, whereas titanium decreased cell motility substantially. The results of this study suggest that optimization of both surface chemistry and topography may be important when designing biomaterials for tissue engineering. In addition, parallel ridges can be used to control the direction and rate of cell migration on the surface.