Silk is a natural non-absorbable suture material that has been widely used for wound ligation; it was the most common natural suture, surpassing collagen, used in the biomedical industry during the past 100 years. During the past 25 years, a range of degradable synthetic sutures has dominated the suture market. However, silk is still popular in ocular, neural, and cardiovascular surgery owing to its advantageous characteristics.

Silk is derived from the cocoon of the silkworm. It is defined as protein fibre. Fibroin chains are believed to be nearly full-extended, highly crystalline, and almost perfectly aligned in the fibre direction, all of which contribute to the fibre’s considerable stiffness and strength. Fibrous proteins, such as silk, are characterised by a highly repetitive primary sequence that leads to significant homogeneity in fine structure. Because of these structural properties it shows impressive mechanical properties and provides important material options in the field of controlled release, biomaterials and scaffolds for tissue engineering.