Multifunctional poly (lactic acid)/vanillin coatings on drug loaded titanium nanotube arrays for improved biocompatibility, corrosion resistance, and antibacterial characteristics

Developing novel and effective methods for producing multifunctional polymeric bioactive coatings with controlled drug release has become a top priority for the scientific community. In the current study, a novel controlled drug delivery system was developed on the surface of a Ti alloy implant using a biodegradable polymer matrix composed of synthetic polymer (Polylactic acid (PLA)), biodegradable polymer (Vanillin (Van)), and antibiotic drug (Gentamycin (GM)) loaded Ti nanotubes (TNT). The chemical structure, microstructure, and surface properties of the TNT and coated surfaces were investigated using SEM/EDS, TEM, XRD, FT-IR, and water contact angle measurements. The obtained results revealed that the PLA/1Van/GM/TNT coatings released GM from the PLA/Van matrix at a linear rate and with a releasing profile over 168 h. The PLA/1Van/GM/TNT coating improved corrosion protection in the simulated body fluid by lowering the passive current density by two orders of magnitude over the bare substrate. After 24 h, the antibacterial efficiency of the PLA/1Van/GM/TNT coating was 94% against Gram + Ve and 95% against Gram-Ve. After 5 days of culturing in MG63 cell lines, the cell proliferation of PLA/1Van/GM/TNT coating was significantly higher than the pure PLA and bare substrate. Furthermore, after 7 days of culture, the number of cells on the PLA/1Van/GM/TNT coating increased significantly, whereas the bare substrate and pure PLA had a slower proliferation rate. The developed biocompatible PLA/Van coatings showed remarkable corrosion-resistant and antibacterial properties, making them potential for biomedical applications.