Harnessing the power of green and rooibos tea aqueous extracts for obtaining colored bioactive cotton and cotton/flax fabrics intended for disposable and reusable medical textiles

Abstract

This study harnesses the potential of green and rooibos tea (GT and RT) aqueous extracts for obtaining colored bioactive cotton and cotton/flax fabrics with intended applications in medical textiles. The chemical characterization of the tea aqueous extracts was conducted using LC–HRMS/MS analysis, resulting in the detection of 129 bioactive compounds. GT demonstrates 2.2 times higher total phenolic content, a 14.7% lower total flavonoid content, and 3 times higher reducing power than RT. Both extracts exhibit excellent antioxidant activity (> 99.8%) and antibacterial activity (99.99%) against both tested bacteria, E. coli and S. aureus. Cotton and cotton/flax fabrics functionalized with GT or RT display outstanding antioxidant (99.63–100%) and antibacterial activity against S. aureus (90.95–99.33%), and high color strength values (5.48–11.08). The cytotoxicity assay confirmed the non-cytotoxic nature of 100% cotton fabric functionalized with GT. This sample additionally demonstrated an antibacterial reduction against E. coli and S. aureus higher than 99% and the highest release of bioactive compounds rendering it highly suitable for disposable medical textiles-wound dressings. To address the shortcomings of functionalized fabrics observed after washing, including decreased antioxidant activity (55.8–81.0%), diminished bacterial reduction, and reduced color strength values (0.80–1.36), copper-based nanoparticles (CuNPs) were biosynthesized in situ on their surfaces utilizing GT and RT aqueous extracts as reducing agents. The successful fabric decoration with CuNPs was proven by quantifying Cu²⁺ uptake, and characterization of the surface chemical composition and morphology of CuNPs. Colored CuNPs-decorated cotton and cotton/flax fabrics exhibited excellent antioxidant (> 98.28%) and antibacterial (99.99%) activity that remained almost unchanged after washing (94.44–98.90% and 99.99%, respectively). These fabrics are non-cytotoxic and characterized by small quantities of released bioactive compounds and Cu²⁺ ions into the physiological saline solution and hold promise as protective, reusable medical textiles suitable for producing gowns and drapes.