Preparation of pH-sensitive medical dressings with Curcumin and Bromothymol blue: characterization and biocompatibility evaluation

Cotton/polyamide 6 medical dressings were successfully dyed with the pH-sensitive dyes Curcumin and Bromothymol blue. The work addressed two different topics: the dyeing process of the medical devices, and the evaluation of the biocompatibility of the dyed textiles. The biocompatibility with human skin was evaluated by means of MTT assay on in vitro cultures of human epithelial cells. The dye potential accumulation in the skin layers was assessed through in vitro permeation studies with Franz cells. The textiles were dyed according to an exhaust dyeing procedure. Both Bromothymol blue and Curcumin dyed samples evidenced a high pH sensitivity in the range from pH 5.5 to 8.5. Almost no dye leaching was observed from the dyed samples, and no influence of the pH sweat was noticeable. The cytotoxicity was evaluated on human keratinocytes. The eluate samples did not show any cytotoxic effect.