Local application of a gentamicin-loaded thermo-responsive hydrogel allows for fracture healing upon clearance of a high Staphylococcus aureus load in a rabbit model

Abstract

Antibiotic-loaded biomaterials (ALBs) have emerged as a potentially useful adjunctive antimicrobial measure for the prevention of infection in open fracture care. A biodegradable thermo-responsive poly(Nisopropylacrylamide) grafted hyaluronic acid (HApN) hydrogel loaded with gentamicin has recently been shown to prevent implant-related infection in a rabbit osteosynthesis model. The primary aim of this study was to determine the influence of this HApN hydrogel on bone healing at an early stage (4 weeks). A rabbit humeral osteotomy model with plating osteosynthesis was used to compare fracture healing in rabbits receiving the hydrogel as compared with control animals. The secondary aim was to observe fracture healing in groups treated with and without antibiotic-loaded hydrogel in the presence of bacterial contamination. In all groups, outcome measures were mechanical stability and histological score, with additional quantitative bacteriology in the inoculated groups.