Mulberry and Non-Mulberry Silk Fibres: Structure, Properties, and Applications in Textiles, Biomedicine, and Sustainable Materials

Abstract

Silk is one of the oldest fibres known to man. It is an animal fibre produced by certain insects to build their cocoons and webs. Silk is primarily produced by silkworms (Bombyx mori and wild species such as Antheraea mylitta, Samia ricini, Antheraea assamensis), and its remarkable combination of mechanical, chemical and biological properties has attracted extensive scientific research. Although many insects produce silk, only the filament produced by the mulberry silk moth Bombyx mori and a few others in the same genus is used by the commercial silk industry. Silk is a natural protein fibre historically valued for its luster, drape and strength, and it has evolved from a luxury textile material to a multifunctional biopolymer with applications in biomedicine, engineering and sustainable materials. This comprehensive review explores the classification of silk fibres, structural and physicochemical characteristics, traditional textile uses, and emerging advanced applications in tissue engineering, drug delivery, smart textiles and eco-materials. With increased global emphasis on sustainable and biocompatible materials, silk stands at the interface of tradition and innovation, offering solutions from luxury fashion to cutting-edge biomedical technologies.

Introduction

Silk is a natural protein-based fibre with a history spanning over 5,000 years, originating in China and spreading globally through the Silk Road. Traditionally valued for its lustre, softness, and luxury appeal, silk is now recognized as a high-performance, sustainable biomaterial. It combines exceptional tensile strength, toughness, flexibility, biodegradability, and biocompatibility. Unlike synthetic polymers, silk is produced under mild, eco-friendly conditions, inspiring bio-based and sustainable material research.

Silk is primarily composed of two proteins: fibroin (70–80%), the structural core responsible for strength and elasticity due to its β-sheet crystalline regions and amorphous domains, and sericin (20–30%), a protective adhesive coating. The hierarchical structure—from molecular arrangement to cocoon architecture—gives silk outstanding mechanical stability, insulation, and environmental resistance.

Silk is classified into mulberry silk and non-mulberry (wild) silks. Mulberry silk, produced by Bombyx mori, dominates global production and is known for uniformity, long filaments, high strength, and superior lustre. Non-mulberry silks include:

• Tussar silk – Coarser, naturally golden-brown, breathable, and eco-friendly.

• Eri silk – “Peace silk,” soft, wool-like, ethically harvested, and thermally insulating.

• Muga silk – Rare, golden-yellow, highly durable, and culturally significant in Assam, India.

Beyond luxury textiles and apparel, silk is widely used in home furnishings, biomedical applications (sutures, scaffolds, drug delivery), cosmetics, composites, flexible electronics, smart textiles, and sustainable materials. Its biocompatibility and controlled biodegradability make it especially valuable in tissue engineering and regenerative medicine.

Overall, silk has evolved from a prestigious textile fibre to a multifunctional, sustainable biopolymer with vast potential in material science, engineering, and advanced technological applications.

Conclusion

Silk is a multifunctional natural fibre that seamlessly bridges traditional textile heritage and modern material science. Its unique molecular structure, hierarchical organization, and sustainable production process contribute to a rare combination of mechanical strength, flexibility, comfort, and environmental compatibility. The diversity of silk types, including mulberry and non-mulberry varieties, provides a wide range of properties suitable for both conventional and advanced applications. With growing interest in sustainable and bio-based materials, silk continues to hold immense potential for innovation in textiles, biomedical engineering, and eco-friendly material development.

References

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Copyright

Copyright © 2026 A. Janani, Dr. K. M. Pachiyappan, Jothi Jerald. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.