Recent advances in nanocellulose scaffold membranes: Sources, processing and functionalization.

Nanocellulose, derived from renewable cellulose resources, has emerged as a highly promising candidate for biomedical scaffold membrane applications owing to its excellent mechanical properties, tunable surface chemistry, biodegradability, and biocompatibility. The performance of nanocellulose-based membrane materials can be significantly enhanced through the integrated regulation of raw material sources, processing and functionalization. This review provides a comprehensive overview of the advances in nanocellulose scaffold membranes from raw material sources, processing technologies, functionalization strategies and biomedical applications. The review especially focuses on how to synergistically integrate these parameters to achieve a balanced design for customizable membranes. Furthermore, a design-oriented conceptual framework for the fabrication of regenerated nanocellulose composite membranes by electrospinning is discussed, which can provide guidance for future material and process development. Despite the preliminary progress achieved to date, several critical bottlenecks continue to hinder practical implementation, including difficulties in pore-structure regulation, long-term biosafety assessment, standardized large-scale manufacturing, and cost-effective production. Overall, this review not only summarizes the latest advancements in nanocellulose-based scaffold membranes, but also points out a future direction for their rational design and biomedical translation.