Spatially controlling neuronal adhesion on CVD diamond

The mechanical and chemical properties of CVD diamond films make them very suitable materials for improving the long-term performance of invasive electrode systems used in brain-computer interfaces (BCIs). We have performed in vitro testing to demonstrate methods for spatially directing neural cell growth and limiting the detrimental attachment of cells involved in the foreign-body response on boron-doped diamond.Laser micro-machining techniques were used to control neuronal adhesion and to modify inflammatory-cell attachment. Laser micromachining was used to etch 100 μm × 1000 μm patterns into poly-D-lysine-coated B-doped diamond. Rat cortical neurons grew well across the coated areas and neuritic outgrowth largely avoided crossing over the etched areas. This avoidance made the etched pattern visible upon staining of the cells and their processes.This work demonstrates that patterns etched into diamond form a spatially defined substrate for organizing neural cell growth. Although preliminary, this work could have further applications in neural-network research and nerve and brain repair scaffolds.

► Growth of neurons on different types of diamond surfaces are compared.
► Oxidised diamond surfaces are excellent for growth of neurons.
► Laser patterning is a novel method to pattern diamond surfaces to control the adhesion of neurons.
► Neurons grow along laser etched pathways in diamond.