Polymethylmethacrylatebased antibacterial coating in vitro and in vivo

Abstract

Nowadays, the infection recurrence rate in osteomyelitis is still high. New hardware not only allowing one to stabilize bone fragments, but also having antibacterial activity seems to be an extremely useful and promising task. The goal of the study was to assess the effectiveness of use of an antibacterial coating based on polymethylmethacrylate cement in experiment and in infected nonunions of long tubular bones of the lower limbs. Bone cement-based coatings impregnated with antibiotics were formed on titanium plates. A plate rinse was carried out; antibiotic concentrations in the rinsed solutions were estimated by a serial broth microdilution method. The antibacterial activity of control and rinsed samples against the antibiotic-sensitive and multiple-antibiotic-resistant Staphylococcus aureus and Pseudomonas aeruginosa strains was estimated by a bilayer agar method. Clinical part. The study included 70 patients divided into 2 groups: osteosynthesis with antibacterial-coated interlocking nail (40 patients, main group) and osteosynthesis with an external fixation device (30 patients, control group) comparable in age, sex and disease duration. The effectiveness of the antibacterial coating was analyzed by the duration of systemic use of antibiotics and infection recurrence rate. The concentrations of meropenem and phosphomycin in the rinsed solutions obtained at one-fold and two-fold treatments were sufficient to suppress the growth of control strains. Vancomycin-containing samples possessed sufficient antibacterial activity against both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) S. aureus strains, double rinse of the samples eliminated their bactericidal properties. The duration of systemic antibacterial therapy in the main group was statistically significantly lower than in the control group (U = 77.5, p < 0.001), and in the main group the infection recurrence rate was lower than 32.5 % vs. 86.7 % (χ2 = 20.39, p < 0.001). The PMMA-based coating impregnated with phosphomycin, meropenem or vancomycin possesses sufficient and long-lasting antibacterial activity, mainly against antibiotic-sensitive strains. An adequate use of such a coating in clinical practice allows one to obtain the desired result of treatment.