Nano-in-nanofibers of pectin reinforced with curcumin loaded chitosan-carrageenan nanosystems as antibacterial wound mats against multidrug resistant pathogens in chronic wounds.

The recent emergence of antibiotic resistance in chronic wound infections requires immediate steps toward alternative strategies for their effective control. Thus, this study was designed to evaluate the antibacterial effects along with the physicochemical properties of curcumin-encapsulated chitosan-carrageenan nanosystems embedded in pectin-based nanofibers (nano-in-nanofibers). Chitosan-carrageenan nanosystems demonstrated high encapsulation efficiency of curcumin (94 ± 0.4 %) with an average size of 41.6 ± 15 nm and surface charge of 31.5 ± 6.3 mV. Fourier transform infrared spectroscopy of nano-in-nanofibers revealed encapsulation of curcumin in chitosan-carrageenan nanosystems (CCNS) by hydrophobic interactions and the presence of hydrogen bonding among curcumin, CCNS, and pectin nanofibers. Scanning electron microscopy of nano-in-nanofibers suggested encapsulation of nanosystems in the nanofibers. Nano-in-nanofibers containing curcumin loaded nanosystems (Cur-CCNS-NF) exhibited a sustained release profile of curcumin as compared to curcumin loaded nanofibers (Cur-NF). Antibacterial and antibiofilm assays revealed that Cur-CCNS-NF significantly inhibited the growth of multi-drug resistant (MDR) Staphylococcus aureus and Pseudomonas aeruginosa than Cur-NF. Cur-CCNS-NF demonstrated high exudate absorbency (73.46 ± 3.72 g/g), low water vapor permeability (0.085 ± 0.005 g/cm2/24 h), high porosity (94.01 % ± 1.78 %), good antioxidant activity (63 % ± 0.70 %), excellent hemocompatibility, and cytocompatibility. Hence, pectin-based nano-in-nanofibers reinforced with curcumin-loaded chitosan-carrageenan nanosystems have potential applications as antibacterial mats against MDR pathogens for chronic wound management.