Enhancing wound dressing efficiency: Cellulose nanofiber sponges loaded with Ganoderma lucidum mycelium fractions

In this study, cellulose nanofiber (CNF)-based sponges incorporating different Ganoderma lucidum biomass fractions were developed and evaluated as bioactive wound dressing materials. Isolated mycelium (G-M), mycelium with exopolysaccharide (G-ME) and purified exopolysaccharide (G-E) fractions were characterized to determine their composition and functionality. The incorporation of fungal biomass significantly altered the structural and physical properties of CNF-based sponges, leading to reduced bulk density, high porosity (>99 %) and increased specific surface area (up to 7.4 m²/g). The type of fungal fraction influenced material behavior: G-M enhanced water absorption (up to 9200 %) and compressive strength, G-E improved network stability and reduced degradation rate in PBS, and G-ME produced the most homogeneous pore structure and highest tensile strength (30 MPa). Scanning electron microscopy (SEM) confirmed a highly interconnected porous morphology with an average pore size close to 100 μm, comparable to those reported for skin substitutes. The sponges exhibited excellent swelling capacity, controlled degradation, and rapid exudate uptake (up to 400 %), confirming their suitability for wound exudate management. Biological evaluations demonstrated hemocompatibility, high cytocompatibility (>90 % cell viability in HaCaT cells), and antioxidant activity. Notably, sponges containing EPS-rich fractions (CNF:G-E and CNF:G-ME) showed a clear bactericidal effect against Staphylococcus aureus, a major wound pathogen, while maintaining superior mechanical and fluid absorption performance. Overall, these findings demonstrate that fungal biomass can act as a natural, low-cost additive to tailor the structure, stability, and bioactivity of CNF-based dressings without extensive purification. The combination of mechanical resilience, biocompatibility, and selective antimicrobial activity supports their potential as multifunctional and sustainable wound dressing materials.