Coffee Husk-Derived Cellulose Nanocrystals Reinforced Multicomponent Electrospun Membranes for Wound Dressing...

The development of multifunctional wound dressing materials while valorizing underutilized agricultural residues represents an opportunity to integrate biomedical functionality with sustainable material design. Coffee husk is a cellulose-rich by-product with potential as a renewable source of reinforcing nanocellulose, yet its integration into multicomponent electrospun wound dressing systems remains limited. In this study, coffee husk was converted into nanocellulose through alkali treatment, bleaching, and acid hydrolysis. The obtained nanocellulose was incorporated at 0.5, 1.0, and 1.5% into electrospun membranes based on poly-(vinyl alcohol) (PVA), alginate, collagen, and Curcuma aeruginosa Roxb. essential oil. The obtained nanocellulose exhibits high crystallinity and predominantly spherical morphology with a particle size of approximately 40-70 nm, although bead formation was observed in several formulas. Nanocellulose incorporation progressively increased tensile strength from 0.91 ± 0.14 MPa for neat PVA to 2.61 ± 0.93 MPa at 1.5% nanocellulose loading. All formulations showed excellent biocompatibility with cell viability values well above 100%, with nanocellulose groups consistently showing the highest cell proliferation. In vivo evaluation using a Staphylococcus aureus-infected rat wound model demonstrated that nanocellulose-incorporated membranes achieved approximately 78% wound healing by Day 12, which is closely comparable to the mupirocin 2% positive control at 85%. The 1.0% nanocellulose formulation was identified as the most balanced and optimal candidate, demonstrating the most uniform fiber diameter (54 ± 8 nm), the most consistent tensile strength (2.26 ± 0.28 MPa), and competitive wound healing performance. These findings confirm the potential of coffee husk-derived nanocellulose as a sustainable and high-performance reinforcing agent for advanced electrospun wound dressing applications.