Scientists from China have investigated the use of silk sericin, a protein that naturally occurs in silkworm cocoons, in biomedical applications. Their findings have been published in the journal Biomaterials.
Historically, silk has been primarily used in the textiles industry, but it has recently been researched for uses in the biomedical industry including tissue engineering, drug delivery, and wearable electronics.
Sericin and fibroin are the two main proteins in silk. Fibroin has been extensively explored for biomedical applications due to beneficial characteristics such as elasticity, biocompatibility, biodegradability, and mechanical properties, while sericin has been unexplored and treated as a waste material in the textiles industry.
Recent research shows that sericin also possesses beneficial properties for the biomedical industry. The material is biodegradable, has low immunogenicity, can promote cell attachment, proliferation, and differentiation, which are essential for biomedical applications such as tissue engineering. Sericin also has antioxidant properties. Modification, cross-linking with other polymers, and precipitation can be used to prepare controllable and stable biomaterials from sericin.
Sericin is found in the periphery of cocoons, the most common being from various species of silkworms. Sericin is water-soluble and composed around 90% by proteins. The presence of random coils can affect properties such as mechanical strength and fragility in dry materials, needing modification by thermal and chemical means.
Varying extraction methods can produce sericin with different conformations. A challenge when using sericin for biomedical applications is the host’s immune response, as sericin is a foreign protein. Thus, the appropriate process must be carefully selected depending on the desired application.
The paper has reviewed current perspectives on silk sericin use in the biomedical industry. Properties and structure of this protein, platforms, applications such as tissue engineering and drug delivery, and future prospects have been highlighted and discussed in depth. It is not yet fully understood how sericin promotes tissue repair. Previous work by the authors has sought to promote clarity on this issue.
Regardless of the current issues with developing commercially viable sericin-based biomaterials for biomedical applications, this natural material shows enormous potential in the future.
By converting silk sericin waste into value-added biomedical products can help solve waste issues in the textiles industry, improving sustainability, circularity, and removing an important source of environmental pollution.