Greener therapeutic pH-sensing wound dressing based on Curcuma Longa and cellulose hydrogel

The moist dressing has been taken as an approach to maintain a wet environment for the wound and accelerate its healing process. Recently, more functionality has been imparted to wound dressings to monitor changes in skin pH and visually indicate the wound healing status. However, providing a biocompatible pH-sensing hydrogel made of green components, at a neutral medium, is yet to investigate. In this work, pH-sensitive natural dye, Curcuma Longa extract (CLE), was utilized as an easy and cost-effective pH-sensitive indicator. CLE was loaded in hydrogel made of hydroxyethyl cellulose grafted with green monomer, itaconic acid (IA), to prepare transparent, soft, and neutral pH-sensitive wound dressing. IA concentrations tuned gel porous structure (370–100 µm), mechanical (686–1186 N, load at break), swelling (up to1839% at neutral medium), and release properties. Hydrogel showed higher release percentages at pH (7.4), and longer release profiles at pH (8 ± 0.2) which suits wound healing applications. The coloristic properties of the CLE as a function of pH were confirmed by UV–Vis spectroscopy. Hydrogel matrices, loaded on cotton gauze and submerged in different pH buffer solutions, showed explicit color changes from visibly yellow for pH ≤ 7 and dark red for pH > 7.