Design of Cefotaxime Sodium-Loaded Polydopamine Coatings with Controlled Surface Roughness for Titanium Implants

The success rate of dental implants is limited by peri-implant infection and insufficient osseointegration. Therefore, reducing the occurrence of peri-implantitis and promoting osseointegration are in demand. A roughened surface has commonly been applied to improve the osseointegration of implants, but it will accelerate the attachment of bacteria. We have developed novel antibiotic-decorated titanium (Ti) surfaces by the immobilization of dopamine and cefotaxime sodium (CS) simultaneously. Moreover, the surface roughness of the polydopamine (PDA)/CS coating was controlled by the changes in polymerization times as determined by atomic force microscopy. Then, all antibiotic-grafted Ti surfaces could effectively prevent the adhesion and proliferation of both Escherichia coli and Streptococcus mutans in comparison to the pristine control. For the culture and osteogenic differentiation of human umbilical mesenchymal stem cells (hUMSCs) on the substrate surface, PDA/CS coating with polymerization times less than 30 min showed acceptable biocompatibility, but the upregulation of marker genes and proteins was detected when the polymerization time was more than 30 min. Moreover, the best calcium deposition results were found in the 30 min PDA/CS group with or without the addition of osteogenic factors. Therefore, our PDA/CS coating with a polymerization time of 30 min holds great potential to design dental implants with dual bacteriostatic and osteogenic properties.