Characterization and Scaled-Up Production of Azido-Functionalized Silk Fiber Produced by Transgenic Silkworms with an...

Area of Science:

• Biomaterials Science
• Genetic Engineering
• Textile Science

Background:

• Functional materials from renewable resources are highly sought after.
• Previous work established genetic code expansion in silkworms (Bombyx mori) to functionalize silk fiber with synthetic amino acids like 4-azido-L-phenylalanine (AzPhe).
• Azido groups serve as reactive handles for biorthogonal chemical reactions.

Purpose of the Study:

• To characterize and scale up the production of azido-functionalized silk fiber.
• To evaluate its suitability for textile, healthcare, and medical applications.
• To demonstrate the creation of functional silk-based materials.

Main Methods:

• Hybridization of the original transgenic silkworm line with a high silk-producing strain to enhance productivity.
• Incorporation of 4-azido-L-phenylalanine (AzPhe) into silk fibroin.
• Characterization of the physical and chemical properties of the functionalized silk fiber.
• Scaled-up rearing of approximately 1000 transgenic silkworms.
• Application of click chemistry for functionalization, including creating fluorescent silk fibers.

Main Results:

• The F₁ hybrid silkworms produced approximately 1.5 times more silk fibroin compared to the original transgenic line.
• The efficiency of AzPhe incorporation into silk fibroin remained high after hybridization.
• The tensile properties of the azido-functionalized silk fiber were comparable to normal silk fiber.
• Successful scaled-up production was achieved.
• Demonstrated the creation of differently-colored fluorescent silk fibers using click chemistry.

Conclusions:

• Scaled-up production of azido-functionalized silk fiber is feasible and yields material with properties similar to native silk.
• This functionalized silk fiber is a versatile platform for developing advanced silk-based materials for diverse applications.
• The ability to introduce specific functions, such as fluorescence, highlights its potential in textile, healthcare, and medical fields.