Bactericidal properties and biocompatibility of a gentamicin-loaded Fe3O4/carbonated hydroxyapatite coating

Postoperative implant-associated infection remains a serious complication in total joint arthroplasty (TJA) surgery. The addition of antibiotics to bone cement is used as an antimicrobial prophylaxis in cemented joint arthroplasty; however, in cementless arthroplasty, there are no comparable measures for the local delivery of antibiotics. In this study, a gentamicin-loaded Fe3O4/carbonated hydroxyapatite coating (Gent-MCHC) was fabricated according to the following steps: (i) deposition of Fe3O4/CaCO3 particles on Ti6Al4V substrates by electrophoretic deposition; (ii) conversions of MCHC from Fe3O4/CaCO3 coatings by chemical treatment; and (iii) formation of Gent-MCHC by loading gentamicin into MCHC. MCHC possessed mesoporous structure with a pore size of about 3.8 nm and magnetic property with the saturation magnetization strength of about 4.03 emu/g. Gent-MCHC had higher drug loading efficiency and drug release capacity, and superior biocompatibility and mitogenic activity than Ti6Al4V. Moreover, Gent-MCHC deterred bacterial adhesion and prevented biofilm formation. These results demonstrate that Gent-MCHC can be used as a local drug delivery system to prevent implant-associated infection in TJA surgery.