Selective Osteoblastic Cell Micro-Arrays on Diamond Films

Abstract

Unique combination of chemical and biocompatible properties with semiconducting properties makes diamond an attractive material for merging solid state and biological systems. Microscopic chemical patterning of diamond films by hydrogen and oxygen surface atoms is used for self-assembly of human osteoblastic cells into micro-arrays. The cell adhesion and assembly on the diamond is further controlled and optimized by cell and protein (fetal bovine serum-FBS) concentration. The cells are characterized by fluorescence microscopy of actin fibers and nuclei. The protein adsorption is studied by atomic force microscopy (AFM). The cells are arranged into arrays on O-terminated patterns. The best cell selectivity is achieved for the lowest cell concentrations of 2500 cells/cm 2. Higher cell concentrations enable to colonize unfavorable H-terminated regions due to mutual cell communication. Based on AFM, the proteins are present on both Hand O-terminated surfaces, however, pronounced differences in the thickness, surface roughness, morphology, and phase images indicate different conformation of the proteins and hence the cell selectivity. There is no cell selectivity when no protein is supplemented in the medium. These results may be applicable in tissue engineering, implants, bio-electronics, and biotechnology in general.