Johnson
Materials Research Group

Spider Silk
Spider silk is a natural material made up strictly of proteins. Spider silk’s durability, elasticity and biocompatibility make it suitable for a wide range of medical applications such as sutures and wound dressings. Spider silk is composed of proteins formed in silk glands of spiders where it is stored as a concentrated liquid solution. As silk is extruded from the spinneret by the spider, the protein solution is dehydrated and aligned forming a fiber. However, producing large quantities of spider silk naturally for biomedical applications is impractical. One solution is to produce recombinant spider silk like proteins in bacterial expression systems (Escherichia. Coli). The objective of this project is to develop and characterize recombinant spider silk fiber mats. Recombinant spider silk fiber mats are produced using electrospinning apparatus. Electrospinning is a process in which a high electric field is applied to polymer or protein solution to spin nano-fibers. Electrospinning of non-woven randomly oriented nano-fibers resembling extra cellular matrix (ECM) structure makes them suitable for regeneration of ECM in wound healing applications.
Figure 1: Electrospun protein fiber mats
To test the biocompatibility of the material, it is essential to investigate cell attachment and growth on the fiber mats. NIH 3t3 Fibroblasts are seeded onto the fiber mats to understand the cell viability and proliferation on the protein fiber mats. Mechanical properties of the recombinant spider silk fiber mats are also determined.
Figure 2: NIH 3t3 Fibroblasts on protein fiber mats