Upcycling of tea processing waste into kombucha-derived bioactive cellulosic composite for prospective wound dressing...

The aim of the study was to utilize kombucha-derived bacterial cellulosic sheet [KBC], formed as a by-product of fermented, sugared black tea (in the presence of a symbiotic culture of bacteria and yeast), for potential wound dressing applications. KBC was functionalized using aqueous and ethanolic extracts of different phytochemical agents using two ex-situ methods- casting and impregnation. It was observed that casted KBC functionalized with ethanolic extract of Turmeric (1.2% w/w) yielded a maximum zone of inhibition (24.37 ± 0.42 mm) against Pseudomonas aeruginosa. The hemocompatibility test confirmed the composite's biocompatible nature as the percentage hemocompatibility was found to be less than 5%. The MTT assay established its viability and anti-cancerous properties with Turmeric extract loaded KBC showing higher efficiency compared to Tulsi extract. FTIR analysis and SEM imaging confirmed the functionalization of cellulose sheets and the change in morphology. The contact angle analysis showed improved hydrophilic properties of the sheets for absorbing wound exudates, and the water absorption study revealed maximum absorptivity of up to 321.20 ± 6.23%. Thus, it can be concluded from the study that tea processing waste can be reused to produce a value-added product that can act as an efficient, cost-effective biomaterial for wound dressing applications.