The effect of combined photobiomodulation and metformin on open skin wound healing in a non-genetic model of type II diabetes

Abstract

© 2017 Elsevier B.V. This study intended to examine the combined influences of photobiomodulation (PBM) and metformin on the microbial flora and biomechanical parameters of wounds in a non-genetic model of type II diabetes mellitus (TII DM). We induced a non-genetic model of TII DM in 20 rats by feeding them a 10% fructose solution for 2 weeks followed by an injection of streptozotocin (STZ, 40 mg/kg). After 21 days from the injection of STZ, we induced one full-thickness skin wound in each of the diabetic rats. We randomly divided the rats into four groups: i) placebo; ii) pulsed wave laser (890 nm, 80 Hz, 0.324 J/cm 2 ); iii) metformin; and iv) laser + metformin. Rats received daily intraperitoneal injections of metformin (50 mg/kg). On days 7and 15 we inspected the microbial flora of each wound. On day 15 we obtained a standard sample from each healing wound for biomechanical analyses. PBM significantly decreased colony-forming units (CFUs) 7 days after wound infliction compared to the placebo group (LSD test, p = 0.012). Metformin significantly enhanced the biomechanical property (stress high load) of the wounds compared to the placebo group (LSD test, p = 0.028). We observed the same significant result for PBM compared to the placebo group (LSD test, p = 0.047). PBM significantly accelerated the wound healing process and significantly reduced CFUs of bacteria in a non-genetic rat model of TII DM.