Preparation of chitosan Hydrogels: The composition of gel formulation will be given prior training. ISDN and chitosan gel will be applied handled under aseptic conditions to the wound, and covered with sterile bandages. The patients will be evaluated every 2 weeks (macroscopic study and measurement of the ulcerated area) until 6 views. A second biopsy will be done one week before the finalization of the treatment of 15 weeks. The biopsies will be embedded on paraformaldehyde (4%) and paraffin. Sections of 5 µm were analyzed by a pathologist to determine hypertrophic and hyperplasic capillaries, inflammation and cellular matrix using Hematoxylin & eosin and Masson's trichrome stains. An immunohistochemical stain was also realized to evaluate several molecular markers such as α-SMA (abcam, Cambridge, MA), Desmin (abcam, Cambridge, MA), VEGF (abcam, Cambridge, MA) and Von Willebrand Factor (Chemicon, CA). (figure 1) Statistical analysis: It will be done using SPSS program for Windows Version 10.0, the results of quantitative variables were expressed in average and standard deviation. The differences between baseline and subsequent pharmacologic intervention measurements will be investigated with the Wilcoxon test. The Mann Whitney U test will be used to compare groups. Frequencies by categories as well as percentages will be quantified for qualitative variables. Comparisons between groups were performed with Chi2. For all comparisons p < 0.05 will be considered as significant.