Titanium Implant Modified With Zinc‐Doped Carbon Dot Layer as an Innovative Coating for the Development of Local Drug Delivery System for Ciprofloxacin

This study presents a new innovative drug delivery system for ciprofloxacin, which is based on the formation of a zinc-doped carbon dots layer on the surface of a titanium alloy (TiAl4V6). In the study, the effectiveness of the synthesis method of a zinc-doped carbon dots layer was determined. The distribution of the layer of carbon dots on the surface of the titanium alloy was investigated using the FT-IR mapping technique, which confirmed the efficiency of the synthesis. The effective synthesis of carbon dots and the coordination of zinc ions on their surface opens the possibility of sorption of ciprofloxacin, which results in a high application potential of the obtained biomaterial. The introduction of zinc cations on the surface of the carbon dots layer resulted in high sorption results of the active substance (40 μg of drug per 1 cm² of implant). The release profile of ciprofloxacin from the modified surface of the titanium alloy indicates that this active substance can be released for up to 4 h. The biomaterial obtained in this work is also hydrophilic (about 40°), which was shown by the contact angle tests. This is an important feature and indicates a high application potential of the performed modification. The resulting layer has antibacterial properties. Growth inhibition for microorganisms such as Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Candida albicans ranged from 74% to 96%. The creation of such a layer on the titanium alloy may reduce the risk of infection during the implantation procedure.