Anti-adhesive bioactive glasses via oligosiloxane deposition and plasma treatment

The development of antimicrobial and anti-adhesive surfaces presents a significant challenge in the advancement of biomaterials, particularly in the context of bioactive materials for bone substitution. This research focuses on the deposition of an anti-adhesive coating using an atmospheric dielectric barrier discharge plasma technology for the surface of two bioactive glasses, SBA2 and S53P4. The obtained materials were characterized from a morphological-compositional point of view, evidencing a uniform coating with a pillar structure. The surface properties, investigated through wettability, roughness, and zeta potential analyses, showed an increased hydrophobicity and the exposition of -NH2 groups. Moreover, since the presence of the coating and plasma treatment can interfere with the bioactivity mechanism, in vitro bioactivity test was performed, highlighting an increased bioactivity kinetics. The surface adhesion behavior of a Multidrug-resistant bacterial strain, Staphylococcus aureus, was estimated by exploiting a preliminary test after 90 min of incubation. The results showed a significant decrease in the colonies attached to the surfaces for both treated glasses compared to the pristine samples. This decrement in bacterial attachment is attributed to the conferment of hydrophobic properties, with a possible role also played by the obtained roughness. This study presents an innovative approach that integrates atmospheric plasma surface modification with bioactive glass technology to develop bone substitute materials that both prevent bacterial colonization and maintain their regenerative capabilities.