Implant-associated
infections in orthopaedic surgeries are very critical as they may hinder bone healing, cause implant failure and even progress to
osteomyelitis. Drug-eluting implants for local delivery of
antibiotics at surgical sites are thought to be promising in preventing
infections. Herein, the
antibiotic vancomycin was encapsulated in a poly(
ethylene glycol) (PEG)-based
hydrogel film that was covalently bound to Ti implants and subsequently covered by a PEG-poly(lactic-co-
caprolactone) (PEG-PLC) membrane. Additionally, crosslinked
starch (CSt) was mixed with the
hydrogel because its porous microstructure is able to inhibit
hydrogel swelling and thus slow down drug release. The release behavior could be regulated by the drug loading and the coating thickness. The
vancomycin-loaded Ti implants showed no initial burst release, offering a sustained drug release for nearly 3 weeks in vitro and more than 4 weeks in vivo. In a rabbit model of S. aureus
infection, the implants with a 4 mg
vancomycin loading significantly reduced the inflammatory reaction and exhibited a good antimicrobial capability. The immobilization of the
antibiotic-loaded polymeric coatings on orthopaedic implants can offer a sustainable drug release with no initial burst release and maintain an effective concentration for a longer time, so it is expected to be an effective strategy to treat and prevent local bone
infections.