Antimicrobial peptides on calcium phosphate-coated titanium for the prevention of implant-associated infections

作者：Kazemzadeh Narbat Mehdi; Kindrachuk Jason; Duan Ke; Jenssen Havard; Hancock Robert E W; Wang Rizhi^*

来源：Biomaterials, 2010, 31(36): 9519-9526.

DOI：10.1016/j.biomaterials.2010.08.035

• Calcium phosphate coating
• Electrolytic deposition
• Antimicrobial peptide
• Titanium
• Infection
• Orthopaedic implants

Prevention of implant-associated infections has been one of the main challenges in orthopaedic surgery This challenge is further complicated by the concern over the development of antibiotic resistance as a result of using traditional antibiotics for infection prophylaxis The objective of this study was to develop a technique that enables the loading and local delivery of a unique group of cationic antimicrobial peptides (AMP) through implant surfaces A thin layer of micro-porous calcium phosphate (CaP) coating was processed by electrolytic deposition onto the surface of titanium as the drug carrier The broad spectrum AMP Tet213 (KRWWKWWRRC) was selected and loaded onto the CaP coating SEM XRD and FTIR analyses confirmed the CaP coating to be micro-porous octacalcium phosphate By using a luminescence spectrometer technique it was demonstrated that a 7 mu m thick porous CaP coating could load up to 9 mu g of AMP/cm(2) using a simple soaking technique The drug-loaded CaP coating (CaP-Tet213) was not cytotoxic for MG-63 osteoblast-like cells The CaP-Tet213 implants had antimicrobial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria with 10(6)-fold reductions of both bacterial strains within 30 min as assessed by measuring colony-forming units (CFU) Repeated CFU assays on the same CaP-Tet213 specimen demonstrated retention of antimicrobial activity by the CaP-Tet213 surfaces through four test cycles The susceptibility of bacteria to the CaP-Tet213 surfaces was also evaluated by assessing the inhibition of luminescence of P aeruginosa containing a luxCDABE cassette at 4 h and 24 h with similar to 92% and similar to 77% inhibition of luminescence respectively It was demonstrated that CaP-Tet213 was a more efficient antimicrobial coating than CaP-MX226 CaP-hLF1-11 or CaP-tobramycin following incubation of CaP implants with equimolar concentrations of Tet213 the commercially developed antimicrobial pepti

• 出版日期2010-12