The engineering lifecycle of fungal chitin-glucan complexes: Extraction, multiscale modification, and translational quality assessment.

Conventional crustacean-derived chitin is constrained by allergen risk, corrosive processing and variable purity. Fungal chitin-glucan complex (CGC) offers a structurally distinct alternative because chitin microfibrils are covalently integrated with β-glucan domains, creating a bicomponent network that links extraction quality to modification potential and biological presentation. This review evaluates fungal CGC across source selection, green extraction, multiscale modification and biomedical translation. Four extraction strategies, deep eutectic solvents, enzymatic methods, ionic liquids and physical field-assisted techniques, are compared using five structural quality indicators: degree of acetylation, weight-average molecular weight, crystallinity index, glucan content and deproteinization efficiency. These parameters define the substrate available for nanoarchitecture formation, chemical derivatization and stimuli-responsive crosslinking, and guide application matching in wound management, tissue engineering, drug delivery, cancer immunomodulation and microbiota-related immune regulation. We further propose the CGC Translational Quality Index (CTQI) as a conceptual decision framework linking extraction sustainability, modification readiness, biomedical evidence, biosafety, regulatory preparedness and manufacturing feasibility. Finally, we outline priorities for standardizing source-to-function material profiles, validating CTQI across laboratories and resolving structure-function mechanisms required for reproducible biomedical translation.