The effect of medical grade honey on tensile strength, strain, and Young's modulus of synthetic absorbable suture material used in equine surgery

Background: Medical grade honey (MGH) has been introduced as a protective measure against surgical site infections in equine surgery, but the effect on suture material has not been investigated. Objective: To evaluate the effect of MGH on the tensile properties of three synthetic absorbable suture materials. Study Design: In vitro experiments. Methods: Ten strands of Polydioxanone USP 2 (PD2), Polyglactin 910 USP 2 (PG2) and Polyglecaprone USP 2-0 (PC2-0) were incubated 1, 7, 14, 21 and 28 days in MGH, phosphate-buffered saline (PBS), equine plasma (EP) and MGH mixed with equine plasma (HP). Mechanical testing was performed recording maximum load at failure (N), strain at failure and Young's modulus (N/mm2). The results were reported from a Welch or regular ANOVA. Results: PD2 in MGH had a significantly higher tensile strength compared to PD2 in EP (p < 0.05, mean difference (md) = 16.95 N, CI95% (9.19–24.70 N)) and PBS (p < 0.05, md = 14.48 N CI95% (6.73–22.23 N)) on day 7 and the remaining time points. PG2 incubated in MGH had a significantly higher tensile strength compared to EP (p < 0.05, md = 69.28 N CI95% (64.16–74.40 N)) and PBS (p < 0.05, md = 56.90 N CI95% (51.78–62.02 N)) until day 28. PC2-0 incubated in MGH had a significantly higher tensile strength compared to EP (p < 0.05 md = 12.40 N CI95% (4.59 N–20.20 N)) and PBS (p < 0.05 md = 11.23 CI95% (3.42–19.03 N)) on day 7 and the remaining time points. Main Limitations: The sutures were unloaded during incubation and a single cycle to failure test was only performed, which does not reflect the in vivo environment where shear forces are present. Conclusions: MGH did not negatively affect the tensile strength of the suture material and can safely be applied in contact with suture materials commonly used in equine surgery.