Valorization of Silkworm Cocoons into Sustainable Nanomaterials: Applications and Challenges.

Silk fibroin (SFb) derived from silkworm cocoons (Bombyx mori) is increasingly recognized as an innovative biodegradable protein for sustainable applications. We discuss its wide biomedical and industrial applications based on the review of 1791 articles from 2001 to 2025 (Scopus). There has been a large increase in research, with 66.44% of publications and 74.84% of citations during 2019-2025. SFb-based nanomaterials have excellent performance in tissue engineering (18.53%), drug delivery (60.59%), and in novel areas, including flexible electronics and sustainable construction, owing to their high strength, controllable structure, and optical transparency. Crucially, exploiting ∼50,000 tonnes of annual silk industry cocoon valorization for aerogels, hydrogels, and NPs promotes the circular economy and minimizes environmental impact using green technologies (lower kg CO2/kg fibroin). These developments make a direct, but by no means exclusive, contribution to the UN Sustainable Development Goals, in particular health (SDG 3), innovation (SDG 9), sustainable production (SDG 12), and climate action (SDG 13). Still, scaling, costs, and the long-term environmental consequences are hurdles. However, such concerns will need to be addressed through sustainable biomanufacturing and life-cycle assessments if SFb can be used to its full potential for a greener future.