Development of a Polycaprolactone and Calcium Peroxide-based coating for Titanium substrates with ROS-generating properties

Bacterial infections are a leading cause of orthopaedic implant failure, and modifications to the implant surface represent an effective strategy to overcome this challenge. In this work, titanium substrates were functionalized with reactive oxygen species (ROS)-generating coatings based on calcium peroxide (CaO₂) embedded in polycaprolactone (PCL). The coatings were deposited by dip-coating and optimized to achieve uniformity, continuity, and reproducibility. Morphological and compositional analyses confirmed the homogeneous incorporation of CaO₂ within the polymeric matrix. Oxygen release studies demonstrated that PCL effectively modulates CaO₂ release, reducing the initial burst and promoting a more sustained oxygen delivery over time. Preliminary antibacterial tests against both Gram-negative and Gram-positive strains indicated an effective reduction in bacterial growth of the CaO₂-containing samples. Simultaneously, no cytotoxic effects were observed on eukaryotic cells, thereby demonstrating the favourable biocompatibility of the coatings. Overall, these findings suggest that PCL/CaO₂ coatings are a promising strategy to provide implant surfaces with antibacterial properties while supporting cellular viability.