Conferring biological activity to native spider silk: A biofunctionalized protein-based microfiber

Area of Science:

• Biomaterials Engineering
• Biotechnology
• Biomolecular Engineering

Background:

• Spider silk possesses exceptional material properties suitable for structural applications.
• Natural spider silk fibers can be modified to organize biological components.
• Existing methods for biomolecular organization can be complex and time-consuming.

Purpose of the Study:

• To demonstrate the use of natural spider silk fibers for organizing biological components.
• To develop rapid and simple biofabrication processes for spider silk.
• To explore the potential of biofunctionalized spider silk in microfluidic devices.

Main Methods:

• Surface modification of micron-scale spider silk fibers with pentaglutamine-tagged biological entities using microbial transglutaminase (mTG).
• Assembly of enzymes, enzyme pathways, antibodies, and fluorescent proteins onto spider silk.
• Spatially defined arrangement of biofunctionalized silk fibers to create secondary levels of biomolecular organization.

Main Results:

• Successful assembly of various biological entities onto spider silk fibers.
• Demonstrated selective capture of carcinoma cells using antibody-conjugated silk arranged perpendicular to flow.
• Observed asymmetric bacterial chemotaxis resulting from asymmetric enzyme conjugation to arranged silk.

Conclusions:

• Biofabrication processes for spider silk are rapid, biologically benign, and require no complex chemistries.
• Engineered spider silk microfibers are flexible, easily manipulated, and functionally active.
• Biofunctional spider silk offers a versatile platform for complex biological functions in biotechnological settings.