Efficacy of antibacterial-loaded coating in an in vivo model of acutely highly contaminated implant

Abstract

PurposeThe purpose of this study was to test the ability of DAC®, a fast resorbable, antibacterial-loaded hydrogel coating, to prevent acute bacterial colonization in an in vivo model of an intra-operatively highly contaminated implant.MethodsA histocompatibility study was performed in 10 adult New Zealand rabbits. Then, methicillin-resistant Staph. aureus were inoculated in the femur of 30 adult New Zealand rabbits at the time of intra-medullary nailing; vancomycin-loaded DAC® coated nails were compared to controls regarding local and systemic infection development.ResultsHistocompatibility study showed no detrimental effect of DAC® hydrogel on bone tissue after 12 weeks from implant. After seven days from implant, none of the rabbits receiving vancomycin-loaded DAC® nail showed positive blood cultures, compared to all the controls; vancomycin-loaded DAC® coating was associated with local bacterial load reduction ranging from 72 to 99 %, compared to controls.ConclusionsVancomycin-loaded DAC® coating is able to significantly reduce bacterial colonization in an animal model of an intra-operatively highly contaminated implant, without local or general side effect.

Fast-resorbable antibiotic-loaded hydrogel coating to reduce postsurgical infection after internal osteosynthesis: A multicenter randomized controlled trial

“…This finding is in agreement with earlier in vivo studies [26,27] and with a recently published multicenter clinical trial on the use of DAC coating in total hip and knee cementless or hybrid total joint replacement [34]. It is also the first clinical demonstration that short-term local prophylaxis may significantly reduce post-surgical septic complications in internal osteosynthesis for closed fractures.…”

“…According to previous studies showing the ability of the hydrogel to resist press-fit insertion [25][26][27], the hydrogel was directly spread onto the implant surface prior to its insertion into the body, a few minutes after reconstitution. Further hydrogel was eventually applied on the synthesis after its positioning on the bone and at the bone-synthesis interface, in order to achieve complete coverage of the implant surface.…”

“…Assuming an average expected rate of SSI after osteosynthesis of 6.0% in the control group [8,9,13] and an SSI rate of 0.1% in the treated group, a sample size of 122 patients in each arm is sufficient to detect a clinically important difference between the two groups with 80% power and 5% level of significance, as calculated using a two-tailed z test of proportions [33]. This significant expected effect size is based upon the rate of post-surgical infection previously investigated in animal models of implant-related infection, using the DAC device [26]. The sample size of 256 patients takes into account an expected drop-out rate of *9%.…”

“…This novel fast-resorbable hydrogel coating (Defensive Antibacterial Coating, DAC Ò ; Novagenit Srl, Mezzolombardo, Italy) is composed of covalently linked hyaluronan and poly-D,L-lactide and is designed to undergo complete hydrolytic degradation in vivo within 48-72 h as well as being able to completely release a variety of different antibacterials at concentrations ranging from 2-10%. The hydrogel showed synergistic antibacterial and antibiofilm activity with various antibiotics and antibiofilm agents in vitro [25], while in vivo it has been proven effective in a rabbit model of highly contaminated implant both with [26] and without systemic prophylaxis, without interfering with bone growth [27]. Following previous brief reports [28,29], we present the clinical results of a multicenter European trial comparing the SSI rate between patients treated with DAC hydrogel-coated osteosynthesis implants and patients treated with noncoated implants.…”

A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

“…The animal study had a limited, but sufficient power to yield statistically significant conclusions and support the findings of our in vitro methods, as currently the use of large numbers of animals in vivo is becoming increasingly troublesome (Richmond, 2002). Although there are several published studies that investigate the in vivo efficacy of antibiotic releasing coatings for the prevention of infection (Giavaresi et al, 2014), relatively fewer studies employ HA-coatings to do so. Alt et al (2006) reported on the efficacy of two different gentamicin-HA-coatings on steel K-wires in the prevention of infection.…”