TiO₂ nanotubular surface functionalization with rosmarinic acid and chitosan: a comparative study of immersion and electrodeposition methods

From the second half of the twentieth century, titanium (Ti) and its alloys have been extensively used in biomedical applications, especially in dental implants. Furthermore, the modification of titanium surfaces to form TiO₂ nanotubular structures has been shown to accelerate osseointegration by increasing surface area and enhancing cell adhesion. Despite these advantages, titanium implants alone can not prevent peri-implantitis, an inflammatory condition of the oral mucosa associated with bacterial colonization during the postoperative period. This inflammation may lead to bone loss and eventual implant failure, highlighting the need for bioactive surface coatings with antibacterial and anti-inflammatory properties. In this context, rosmarinic acid (RA) and chitosan emerge as promising candidates due to their well-known biological activities. Among the techniques available for functionalizing TiO₂ nanotubular surfaces, immersion and electrodeposition are widely used methods that can result in different levels of bioactive compound adsorption. Therefore, the aim of this study was to evaluate which of these methods is more suitable for functionalizing TiO₂ nanotubular surfaces with RA and chitosan, considering the amount of adsorbed material and potential application in dental implants. The methodology involved the synthesis of TiO₂ nanotubes, surface functionalization using both methods, and physicochemical and morphological characterization. Scanning Electron Microscopy (SEM) results demonstrated higher adsorption of RA and chitosan on surfaces functionalized by immersion, indicating that this method is more effective than electrodeposition for coating TiO₂ nanotubular surfaces.