Effect of the enzyme-containing polymeric nanoparticles on mmp-2 activity during burn wound healing in rats with streptozotocin-induced diabetes

Relevance. Diabetic foot syndrome is a common complication that is characterized by the development of chronic ulcers. Among the mechanisms of impaired wound healing, the leading role is played by disturbance of extracellular matrix homeostasis: chronic hyperglycemia, on the one hand, promotes the formation of so-called advanced glycation end products (AGEs), which mediate pro-inflammatory activation of immune cells, and on the other hand, inhibits fibroblasts proliferation and collagen production, disrupts the migration of keratinocytes and endothelial cells. Therefore, the elimination of AGEs is a pathogenetic approach in diabetic wound treatment. For this purpose, a composite consisting of polyspecific microbial proteinases fixed on polymeric porous nanoparticles was developed. The activity of matrix metalloproteinase-2 (MMP-2) was chosen as a prognostic indicator of chronic wound healing. Objective: to study the activity of MMP-2 in the tissues of the burn wound of rats with simulated diabetes mellitus under the influence of enzyme-containing nanoparticles. Materials and methods. N = 48 Wistar rats were used in the experiment. Diabetes mellitus was induced by administration of 50 mg/kg of streptozotocin. To model the wound in rats, a standard animal model of thermal burns by Walker and Mason was used. Thermal damage corresponded to the II-IIIA degree of burns, and occupied 19±1.6% of the total area of ​​animal skin. Rats were divided into two groups of 24 animals each: the DM group did not receive any treatment, and rats from the DM+T group were daily applied to the burn wound with the mentioned composite (enzyme-containing nanoparticles). Animals were removed from the experiment on days 3, 7, 14 and 21 of observation. The activity of MMP-2 in the tissues of the burn wound of diabetic rats was studied by gelatin zymography, expressed in arbitrary units (AU). Statistical data processing was performed in the software package SPSS Statistics Base, v.22 with Student and Scheffe tests. Results. The level of activity of MMP-2 in the tissues of the burn wound of rats in the DM group on the 3rd day of the study was 4.9 ± 1.3 AU, increased by 7 days (p <0.01) and reached a maximum level of 52.55 ± 3.06 AU at day 14 (p <0.01). On day 21, the activity of the test enzyme decreased by 8.5 AU (p <0.01), compared to day 14. On day 3 of the study in the DM+T group, the activity of MMP-2 in the diabetic wound was 15.93 ± 2.68 AU and gradually decreased (p <0.01) to 5.67 ± 2.67 AU on day 14. However, on day 21, the second peak (p <0.01) of the activity of the studied enzyme was observed - 33.64 ± 4.1 AU. When comparing the two groups (DmM and DM+T) on day 3 of the study, the activity of MMP-2 in the tissues of the burn wound of rats in the DM+T group was three times higher (p <0.01) than in the DM group. But from the 7th day the activity of MMP-2 in the DM group was higher than the DM+T group. On day 21 of the study, the level of MMP-2 in the DM group remained higher (p <0.01) than in the DM+T group. Conclusions. The use of enzyme-containing nanoparticles provides effective degradation of glycosylated components of the extracellular matrix (AGEs), thereby reducing the inflammatory process and activity of MMP-2, and promoting wound healing in rats with streptozotocin-induced diabetes.