Parylene coatings on stainless steel 316L surface for medical applications — Mechanical and protective properties

The mechanical and protective properties of parylene N and C coatings (2–20 μm) on stainless steel 316L implant materials were investigated. The coatings were characterized by scanning electron and confocal microscopes, microindentation and scratch tests, whereas their protective properties were evaluated in terms of quenching metal ion release from stainless steel to simulated body fluid (Hanks solution). The obtained results revealed that for parylene C coatings, the critical load for initial cracks is 3–5 times higher and the total metal ions release is reduced 3 times more efficiently compared to parylene N. It was thus concluded that parylene C exhibits superior mechanical and protective properties for application as a micrometer coating material for stainless steel implants.

► Parylene biocompatible coating was applied for steel implant surfaces by CVD method.
► Mechanical and protective properties of polymer layers were determined.
► Rival discrimination between parylene N and C on steel 316L was performed.
► Total metal ions release was reduced more efficiently by parylene C coating.
► Critical load for initial cracks was 3–5 times higher for parylene C coating.