In the field of implantable
titanium-based
biomaterials,
infections and
inflammations are the most common forms of postoperative complications. The controlled local delivery of
therapeutics from implants through
polyelectrolyte multilayers (
PEMs) has recently emerged as a versatile technique that has shown great promise in the transformation of a classical medical implant into a drug delivery system. Herein, we report the design and the elaboration of new biodegradable multidrug-eluting
titanium platforms based on a
polyelectrolyte multilayer bioactive coating that target
infections. These systems were built up in mild conditions according to the layer-by-layer (L-b-L) assembly and incorporate two biocompatible
polysaccharides held together through electrostatic interactions. A synthetic, negatively charged β-
cyclodextrin-based
polymer (PCD), well-known for forming stable and reversible complexes with hydrophobic therapeutic agents, was exploited as a multidrug reservoir, and
chitosan (CHT), a naturally occurring, positively charged
polyelectrolyte, was used as a barrier for controlling the
drug delivery rate. These
polyelectrolyte multilayer films were strongly attached to the
titanium surface through a bioinspired
polydopamine (PDA) film acting as an adhesive first layer and promoting the robust anchorage of
PEMs onto the
biomaterials. Prior to the multilayer film deposition, the interactions between both oppositely charged
polyelectrolytes, as well the multilayer growth, were monitored by employing surface plasmon resonance (SPR). Several
PEMs integrating 5, 10, and 15 bilayers were engineered using the dip coating strategy, and the
polyelectrolyte surface densities were estimated by colorimetric titrations and gravimetric analyses. The morphologies of these multilayer systems, as well as their naturally occurring degradation in a physiological medium, were investigated by scanning electron microscopy (SEM), and their thicknesses were measured by means of profilometry and ellipsometry studies. Finally, the ability of the coated
titanium multilayer devices to act as a
drug-eluting system and to treat
infections was validated with
gentamicin, a relevant water-soluble
antibiotic commonly used in medicine due to its broad bactericidal spectrum.