Design of a biocompatible Curcuma aromatica functionalized bacterial cellulose polymer composite as a bioactive wound dressing

Abstract

Bacterial cellulose (BC), a pure counterpart of plant cellulose is produced by acetic acid bacteria, particularly species of the genus Komagataeibacter, through the metabolization of sugars. Curcuma aromatica (CA), commonly known as wild turmeric or kasturi manjal in India, has been traditionally used for its potent antimicrobial and antioxidant properties in the treatment of wounds, acne, and various skin disorders. Leveraging these bioactivities, CA was incorporated into BC to fabricate a novel BC-CA composite aimed at enhancing its therapeutic efficacy for wound healing applications. HRLCMS confirmed that C. aromatica contained diverse bioactive metabolites, including curcuminoids alongside terpenoids, phenylpropanoids, and other phytochemicals. The UV-Vis and photoluminescence analyses revealed distinct optical properties between curcumin and C. aromatica, reflecting differences in their molecular structure and phytochemical composition. While curcumin showed a single intense absorption and emission profile, C. aromatica exhibited broader absorption and dual emission peaks due to the presence of multiple interacting bioactive constituents. Photostability studies on BC-CA film showed that light exposure, especially sunlight, led to partial photodegradation of curcuminoids, resulting in decreased chromophoric intensity without significant changes in chemical structure. Physico-chemical characterisation confirmed successful adsorption of CA onto the BC matrix. Antimicrobial assays demonstrated that BC-1 percent CA exhibited significantly higher bactericidal activity compared to BC- 0.5 percent CA, with the highest inhibition observed against Staphylococcus aureus (MTCC 737). The antibacterial mechanism involved intracellular Reactive Oxygen Species (ROS) generation with concomitant bacterial membrane disruption. Furthermore, ABTS antioxidant assays, MTT cytotoxicity tests, and haemocompatibility studies revealed that the BC-CA composites possess potent antioxidant activity while maintaining excellent biocompatibility and haemocompatibility. In vivo wound healing studies showed 99 percent wound closure on day 14 by BC1 percent CA composite film which was better than the positive control (mupirocin). Histological evaluation showed that the bioactive BC scaffold significantly increased re-epithelialization, reduced inflammation and enhanced collagen organisation.