Characterisation of impaired wound healing in a preclinical model of induced diabetes using wide‐field imaging and conventional immunohistochemistry assays

Abstract

Major complications of diabetes lead to inflammation and oxidative stress, delayed wound healing, and persistent ulcers. The high morbidity, mortality rate, and associated costs of management suggest a need for non‐invasive methods that will enable the early detection of at‐risk tissue. We have compared the wound‐healing process that occurs in streptozotocin (STZ)‐treated diabetic rats with non‐diabetic controls using contrast changes in colour photography (ie, Weber Contrast) and the non‐invasive optical method Spatial Frequency Domain Imaging (SFDI). This technology can be used to quantify the structural and metabolic properties of in‐vivo tissue by measuring oxyhaemoglobin concentration (HbO2), deoxyhaemoglobin concentration (Hb), and oxygen saturation (StO2) within the visible boundaries of each wound. We also evaluated the changes in inducible nitric oxide synthase (iNOS) in the dermis using immunohistochemistry. Contrast changes in colour photographs showed that diabetic rats healed at a slower rate in comparison with non‐diabetic control, with the most significant change occurring at 7 days after the punch biopsy. We observed lower HbO2, StO2, and elevated Hb concentrations in the diabetic wounds. The iNOS level was higher in the dermis of the diabetic rats compared with the non‐diabetic rats. Our results showed that, in diabetes, there is higher level of iNOS that can lead to an observed reduction in HbO2 levels. iNOS is linked to increased inflammation, leading to prolonged wound healing. Our results suggest that SFDI has potential as a non‐invasive assessment of markers of wound‐healing impairment.

Evaluation of keratin biomaterial containing silver nanoparticles as a potential wound dressing in full‐thickness skin wound model in diabetic mice

“…Among the most interesting and promising applications of keratin, biomaterials are used in nerve regeneration or wound healing dressing of acute or chronic wounds. Impaired wound healing is a hallmark in patients with diabetes mellitus (Saidian et al, ). Moreover, diabetic wounds are highly prone to secondary infections.…”

IDE Degrades Nociceptin/Orphanin FQ through an Insulin Regulated Mechanism

“…Two major diabetes types can develop (not considering gestational diabetes): type 1 and type 2, characterized by a lack of insulin (Ins) production and by Ins resistance, respectively. Common symptoms and problems of untreated diabetes are excessive thirst and hunger, visual disturbances, frequent urination (from urinary tract infections or kidney problems), weight loss or gain, fatigue, risk of heart disease and infections, irritability, slow-healing wounds, damaged blood vessels, and nerve damage [2,3,4]. Moreover, diabetic patients have a high pain threshold [5,6], whereas Ins has an antinociceptive effect, widely reported in the literature [7].…”

Evaluation of Hemodynamics in a Murine Hindlimb Ischemia Model Using Spatial Frequency Domain Imaging

“…It has been applied to study the effects of renal arterial occlusion in a porcine model that simulates renal‐ischemic reperfusion injury typically observed in partial nephrectomy procedures [36]. Other clinical studies show that SFDI can be used to assess perfusion in the lower extremities of diabetic and nondiabetic patients [22], particularly in the wound [37] and burn imaging [38] in which SFDI can assess where a loss in tissue oxygenation may lead to poor circulation and thus poor healing, provoking the formation of ulcers that are common among patients with diabetes [37].…”