Ancient fibrous biomaterials from silkworm protein fibroin and spider silk blends: Biomechanical patterns

Silkworm silk protein fibroin and spider silk spidroin are known biocompatible and natural biodegradable polymers in biomedical applications. The presence of beta-sheets in silk fibroin and spider spidroin confor-mation improves their mechanical properties. The strength and toughness of pure recombinant silkworm fibroin and spidroin are relatively low due to reduced molecular weight. Hence, blending is the foremost approach of recent studies to optimize silk fibroin and spidroin's mechanical properties. As summarised in the present review, numerous research investigations evaluate the blending of natural and synthetic polymers. The effects of blending silk fibroin and spidroin with natural and synthetic polymers on the mechanical properties are discussed in this review article. Indeed, combining natural and synthetic poly-mers with silk fibroin and spidroin changes their conformation and structure, fine-tuning the blends' mechanical properties.Statement of significanceSilkworm and spider silk proteins (silk fibroin and spidroin) are biocompatible and biodegradable natural polymers having different types of biomedical applications. Their mechanical and biological properties may be tuned through various strategies such as blending, conjugating and cross-linking. Blending is the most common method to modify fibroin and spidroin properties on demand. This review article aims to categorize and evaluate the effects of blending fibroin and spidroin with different natural and syn-thetic polymers. Increased polarity and hydrophilicity end to hydrogen bonding triggered conformational change in fibroin and spidroin blends. The effect of polarity and hydrophilicity of the blending compound has been discussed in relation to the structural and mechanical properties of the biomaterials. These ef-fects have been categorized to combinatorial, synergistic and indirect impact on silk fibroin and spidroin properties. This outlook guides us to choose the blending compounds mindfully as this mixing affects the biochemical and biophysical characteristics of the biomaterials (c) 2022 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Automated summary

Silkworm silk protein fibroin and spider silk spidroin are biocompatible and biodegradable polymers with potential applications in biomedicine. Blending, as a common method, can improve their mechanical properties by modifying their conformation and structure.