Electrophoretic deposition of gentamicin and chitosan into titanium nanotubes to target periprosthetic joint infection

Abstract Periprosthetic joint infection (PJI) occurs in 1%–2% of primary total hip and knee arthroplasties; the rate can reach 20% in individuals at risk. Due to the low local bioavailability of systemic antibiotics and possible off‐target effects, localized drug delivery systems are of great importance. Our aim was the electrophoretic deposition (EPD) of gentamicin and chitosan in Titanium (Ti) nanotubes to establish a local, prolonged antibiotic delivery. Nanotubes were created on Ti wire with a two‐step anodization process. For drug deposition, EPD and the air‐dry methods were compared. For a prolonged drug release, gentamicin and crosslinked chitosan were deposited in a two‐step EPD process. Drug release was quantified by fractional volume sampling. The Ti wires were tested against Staphylococcus aureus by agar dilution and liquid culture methods. MC3T3‐E1 osteoblastic cell viability was determined with trypan blue. Nanotubes were characterized by a 100 nm diameter and 7 μm length. EPD allowed a higher amount of gentamicin deposited than the air‐dry method. Drug deposition was controllable by adjusting the voltage and duration of the EPD process. The crosslinked chitosan layer allowed diffusion‐driven release kinetics for up to 3 days. Gentamicin‐loaded Ti wires significantly inhibited bacterial growth and resulted in a larger inhibition zone compared to unloaded wires. Twenty‐four hours of incubation with loaded wires did not have a significant effect on osteoblast viability. Gentamicin‐loaded Ti nanotubes represent a promising approach for PJI prevention, as well as a valuable preclinical tool for the investigation of localized drug delivery systems created on Ti surface.