Prophylactic antibiotic bone cements are extensively used in orthopaedics. However, the development of antimicrobial resistance to antibiotics, demonstrates a need to find alternative treatments. Herein, an antimicrobial honey (SurgihoneyRO-SHRO) has been successfully incorporated into a calcium sulphate (CS) based cement to produce a hard tissue scaffold with the ability to inhibit bacterial growth. Antimicrobial properties elicited from SHRO are predominantly owed to the water-initiated production of reactive oxygen species (ROS). As an alternative to initially loading CS cement with SHRO, in order to prevent premature activation, SHRO was added into the already developing cement matrix, locking available water into the CS crystal structure before SHRO addition. Promisingly, this methodology produced > 2.5 times (715.0 ± 147.3 μM/mL/g) more ROS over 24 h and exhibited a compressive strength (32.2 ± 5.8 MPa) comparable to trabecular bone after 3 weeks of immersion. In-vitro the SHRO loaded CS scaffolds were shown to inhibit growth of clinically relevant organisms, Staphylococcus aureus and Pseudomonas aeruginosa, with comparable potency to equivalent doses of gentamicin. Encouragingly, formulations did not inhibit wound healing or induce an inflammatory response from osteoblasts. Overall this study highlights the prophylactic potential of CS-SHRO cements as an alternative to traditional antibiotics.
Bibliographical noteFunding Information:
Thomas J. Hall and Erik A. B. Hughes are joint first authors of the manuscript. This study was funded by the EPSRC (Project number 1823302—novel antimicrobial delivery systems) undertaken in collaboration with Matoke Holdings Ltd, and also by the National Institute for Health Research (NIHR) Surgical Reconstruction and Microbiology Research Centre (SRMRC). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.