Minocycline-Loaded Agarose Hydrogel Mitigates Burn Wound Progression and Controls Infection in the Management of Deep...

Severe burns present significant challenges in military and civilian settings, especially in austere environments where care may be delayed. This study presents a multifunctional, deployable hydrogel dressing composed of agarose and minocycline (8 mg/mL) designed to prevent burn progression, control infection and promote healing. Agarose hydrogel formulations containing between 0.5% and 1.25% agarose were characterised by rheology, and their drug-release kinetics were measured. Based on rheological characterisation (Pa · s) and minocycline release rates, hydrogels containing 1% agarose were used in subsequent studies. In vitro studies measured the rate of minocycline diffusion through burnt porcine skin (1.5 μg/h), and the minocycline hydrogel effectively inhibited growth of S. aureus, P. aeruginosa and A. baumannii in wound tissue, as measured by colony-forming units (CFU). In porcine deep partial-thickness burns, the minocycline hydrogel reduced inflammation compared to silver sulfadiazine (SSD) and gauze controls, as indicated by lower levels of interleukin (IL)-1β and IL-6 (pg/ml) in wound tissue, and mitigated burn progression, resulting in significantly shallower burns by Day 4 compared with blank hydrogel, SSD and gauze controls. By Day 14, re-epithelialization reached 70% ± 12% for burns treated with the minocycline hydrogel, compared to 51%-58% for controls. Bacterial load was significantly reduced in infected burns treated with the minocycline hydrogel compared with blank hydrogel on Day 4, compared with all control groups on Day 7, and compared with blank hydrogel on Day 14. These results demonstrate that minocycline agarose hydrogel provides mitigation of burn wound progression, and effective infection control, representing a promising strategy for burn care, particularly in settings with limited or delayed access to specialised treatment.