Polyhexamethylene biguanide (PHMB) is a broad-spectrum antiseptic which avoids many efficacy and toxicity problems associated with antimicrobials, in particular, it has a low risk of loss of susceptibility due to acquired antimicrobial resistance. Despite such advantages, PHMB is not widely used in wound care, suggesting more research is required to take full advantage of PHMB’s properties. We hypothesised that a nanofibre morphology would provide a gradual release of PHMB, prolonging the antimicrobial effects within the therapeutic window. PHMB:polyurethane (PU) electrospun nanofibre membranes were prepared with increasing PHMB concentrations, and the effects on antimicrobial activities, mechanical properties and host cell toxicity were compared. Overall, PHMB:PU membranes displayed a burst release of PHMB during the first hour following PBS immersion (50.5–95.9% of total released), followed by a gradual release over 120 h (≤25 wt % PHMB). The membranes were hydrophilic (83.7–53.3°), gradually gaining hydrophobicity as PHMB was released. They displayed superior antimicrobial activity, which extended past the initial release period, retained PU hyperelasticity regardless of PHMB concentration (collective tensile modulus of 5–35% PHMB:PU membranes, 3.56 ± 0.97 MPa; ultimate strain, >200%) and displayed minimal human cell toxicity (<25 wt % PHMB). With further development, PHMB:PU electrospun membranes may provide improved wound dressings.

Diabetic chronic wounds cause massive levels of patient suffering and economic problems worldwide. The state of chronic inflammation arises in response to a complex combination of diabetes mellitus-related pathophysiologies. Advanced treatment options are available; however, many wounds still fail to heal, exacerbating morbidity and mortality. This review describes the chronic inflammation pathophysiologies in diabetic ulcers and treatment options that may help address this dysfunction either directly or indirectly. We suggest that treatments to reduce inflammation within these complex wounds may help trigger healing.chronic wounds, diabetes, diabetic ulcers, inflammation, wound healing Key Messages• treatments that aim to reduce inflammation may help trigger healing in chronic diabetic wounds. | INTRODUCTIONDiabetes mellitus is a chronic metabolic condition of insulin resistance, reduced insulin production, and chronically elevated blood glucose levels. The global prevalence of diabetes has trebled in the last two decades, particularly in countries with developing economies, and is predicted to affect 1 in 10 people worldwide by 2045. 1 Diabetic foot ulceration is one of the major complications of diabetes. It is a serious, highly morbid condition, which has been shown to be independently associated with increased mortality. 2 Patients with diabetes mellitus are especially prone to developing foot ulceration due to peripheral neuropathy, which leads to biomechanical changes to the foot and loss of protective reflexes and sensation to injury. [3][4][5] The presence of peripheral vascular disease and a predilection to polymicrobial infection are also contributing factors. As many as one in three patients with diabetes mellitus will develop a diabetic foot ulcer during their lifetime. 3,4,6,7 The prognosis for patients suffering from diabetic foot ulceration is bleak. Thirty three percent of diabetic ulcers do not heal and remain as chronic wounds. 8 Of those ulcers that do achieve 'healing', 65% will experience re-Work carried out in the above institutions (1, 2).