The Doping of a Carbon Coating with Phosphorus as a Potential Way of Improving the Biological Properties of Diamond-like Carbon

The potential of diamond-like carbon coatings in medicine can be increased by doping them with various elements. Such modifications especially affect the biological properties of the synthetized films. In the following research, phosphorus was introduced into the carbon matrix by means of the chemical vapor deposition technique and using an organic precursor. With the addition of about 1.6 and 4.3 at% of dopant, not only was the surface roughness increased, but significant changes in both the mechanical and biological properties were also observed. The presence of phosphorus reduced the hardness of DLC coatings but still improved this parameter in comparison to the substrate material-AISI316LVM. A biological examination revealed the bacteriostatic potential of doped coatings regardless of their chemical composition. Increasing the amount of phosphorus improved the proliferation of osteoblasts (<i>Saos-2</i> cell), but the opposite effect was achieved for the endothelial cell line (<i>EA.hy926).</i> Another important aspect is the reduction in platelet activation, especially for low amounts of dopant.