Comparative study of superhydrophilic and superhydrophobic TiO2/epoxy coatings on AISI 316L stainless steeel : surface properties and biocompatibility

Kocijan A, Conradi M, Hońćevar M, Drobne D
[ site ] Materiali in tehnologije, 2018

TiO2/epoxy coatings were successfully applied to the surface of AISI 316L stainless steel to change the wetting properties, with the aim being to improve the biocompatibility of the superhydrophobic/superhydrophilic surfaces. Contact-angle measurements were used to evaluate the wetting properties of the non-coated, epoxy-coated, as-received TiO2/epoxy-coated and fluoroalkylsilane (FAS)-TiO2/epoxy-coated substrates. The as-received TiO2/epoxy coating and FAS-TiO2/epoxy coating showed superhydrophilic and superhydrophobic characteristics, respectively. The average surface roughness (Sa) of the superhydrophobic surface was higher compared to the superhydrophilic surface due to the formation of agglomerates. The biocompatibility evaluated by cell attachment showed that AISI 316L stainless steel with a hydrophilic nature and low Sa is the most favourable surface for bone osteosarcoma cells (MG-63) growth. On the other hand, the two limiting cases of surfaces, superhydrophilic and superhydrophobic coatings with increased roughness compared to AISI 316L, showed lower biocompatibility