The use of p-toluenesulfonic acid in the removal of biofilm in chronic ulcers

Background: Bacterial biofilms represent a topic of great concern due to their ability to cause chronic, sometimes fatal infections. Considering the prevalence and pathogenicity of biofilms in chronic ulcers, an observational study was designed to evaluate the anti-biofilm capabilities of p-toluenesulfonic acid, using it in the chronic ulcers of patients belonging to the Diabetic Foot clinic. Methods: Preliminary analysis of an observational study on patients attending the diabetic foot clinic with leg ulcers for at least 4 weeks. 17 patients treated with p-toluenesulfonic acid on a weekly basis for a maximum of 16 weeks. The primary outcome was 100% granulation tissue formation at week 16 and 50% reduction in initial chronic ulcer size. Results: The average treatment time was 10 ± 4.8 weeks. 8 patients healed, 7 are undergoing treatment, 1 required reoperation due to post-operative complications and 1 spontaneously dropped out of the study after 6 weeks. In the sample of healed patients, the average treatment time was 10.5 weeks with 100% granulation present at the 6th week. The reduction in the overall size of the ulcer and of the granulation area is not significant in the total sample. The data improves in the sample of healed patients even if it does not reach significance (lesion p-value 0.094, granulation p-value 0.13). Applying the analysis to the delta of the two variables, a measurement of the area that coincides with the margins of the ulcer, a p-value of 0.069 is obtained. The behaviour of the sample does not change when stratified by the dressings applied after treatment with p-toluenesulfonic acid. Conclusions: Treatment with p-toluenesulfonic acid promotes tissue granulation regardless of the type of dressing subsequently applied. The data on the evolution of the size of the lesions were not significant due to the smallness of the sample but in the sample of healed persons, the formation of granulation after an average of 6 applications transforms the "chronic" ulcer into an "active" ulcer, promoting closure within the subsequent 4 weeks. The appearance of granulation confirms healing. Elimination of biofilm with p-toluenesulfonic acid can reduce healing times and the risk of reinfection.