Correlative microscopic characterization of biomechanical and biomimetic advanced CVD coatings on a PEEK substrate

Direct oesteointegration between a polymeric implant made of a polymer such as a PEEK and host tissues involves direct connection via surface energy, which can be increased by plasma surface modification. Thin coatings are preferably produced by deposition from the gaseous phase (CVD - chemical vapour deposition). In the frame of this research study, PEEK substrates were modified by the PTFE + SiO2/organic silicone multilayer structures that were designed via a biomimetic concept based on algae shell structures. The coatings exhibited mechanical wear resistance and ensured adequate human fibroblast cell proliferation. The proliferation was characterized using confocal microscopy. The analysis together with detailed microstructural characterization with transmission electron microscopy techniques (TEM) established a complex correlative microscopy characterization and allowed the determination of the mechanical and biological features of the coatings. High-resolution TEM (HRTEM) observations revealed possibilities of gas circulation in between the substrate material and the outside environment without making direct contact.