IDF21-0365 Treatment with AnxA12-26 gel improves healing properties in an experimental skin lesion after induction of T1DM

Background: Diabetes mellitus (DM) is characterized by metabolic alterations that involve defects in the secretion and/or action of insulin, being responsible for several complications, such as poor healing. In diabetic people, healing is impaired by changes in the inflammatory response and regulatory mechanisms. Recent studies by our research group have shown that the annexin A1 protein (AnxA1) is involved in the regulation of inflammation, apoptosis, cell growth and differentiation. Aim: To develop an economically viable gel of carboxymethylcellulose (CMC) containing the peptide AnxA12-26 and evaluate its effect on skin lesions in type 1 diabetes mellitus (T1DM). Method: The analysis of the gel was performed using organoleptic characteristics, pH and UV-Vi spectroscopy to assess the absorption and fluorescence emission profile of the free and gel-associated peptide. Skin lesions were performed in C57BL/6 control (non-diabetic) and diabetic mice in periods of 3, 7 and 14 days. The following aspects were evaluated: weight and blood glucose; macroscopic analysis; histopathology of scar and adjacent tissue; the expression of ED-1 positive macrophages in the healing process; expression of matrix metalloproteinases (MMP-9) and analysis of the anti-inflammatory protein AnxA1. Results: The gel/AnxA12-26 kept at 4°C showed better results in the parameters of pH and organoleptic characteristics. The UV-Vi spectroscopy analyzes confirmed the presence of the peptide in three-dimensional hydrogel matrix. Diabetic animals, treated or not, showed weight loss and increased blood glucose compared to controls, confirming the efficacy of DM1 induction. Treatment with gel/AnxA12-26 showed evolution of the healing process, reduction of inflammatory infiltrate, re-epithelialization and beginning of remodeling in control and diabetic animals. The effectiveness of the gel/AnxA12-26 was also observed in immunohistochemical analyzes through macrophage modulation, modulation of MMP-9 expression and reduction of endogenous annexin A1 in the control and diabetic groups. Conclusion: Together, our results were innovative in the formulation of the hydrogel with the peptide AnxA12-26, showing efficiency in the cutaneous healing process and indicating its possibility to increase the therapeutic arsenal, at a viable cost, for the treatment of diabetic wounds.