Production of a novel silk-like protein from sea anemone and fabrication of wet-spun and electrospun marine-derived silk fibers

Abstract

Silk-based biomaterials, which for centuries were primarily used as the raw materials for textile fabrics, are now being used in the medical, food and industrial fields because of their extraordinary properties. Their advantageous characteristics include high strength, extensibility, biocompatibility, biodegradability and minimal production of inflammatory reactions. To date, only silkworm silk has been applied in mass-produced technological applications, but spider silk proteins have been extensively studied because of their superior mechanical stability. Here we report the discovery of a novel silk-like protein (named aneroin) from the sea anemone Nematostella vectensis and the successful fabrication of wet-spun and electrospun silk fibers from purified recombinant aneroins. Aneroin fibers have promising mechanical properties, similar to those of recombinant spider silks with molecular weights of ∼100 kDa and those of natural mammalian tendon collagen. The results of this study demonstrate that aneroin, a new repertoire of silk-like protein found in sea anemones, has potential for use as a novel fibrous biomaterial. Its use would expand the applications of silk in the development of multifunctional and bio-inspired materials. A highly sought-after fabric for thousands of years, silk has also proved valuable to the industrial, food and medical fields — with applications in wound dressings or tissue engineering scaffolds, for example. The varied uses of this biomaterial arise from its attractive set of properties: it is strong, extensible, biocompatible and biodegradable. Silk is composed of proteins that can be processed into fibres; those used for large-scale applications are typically derived from the silkworm Bombyx mori or, to some extent, spiders. A Korean-based team led by Hyung Joon Cha from the Pohang University of Science and Technology has now discovered a silk-like protein — aneroin — in a marine organism, the sea anemone Nematostella vectensis. The researchers used the bacterium Escherichia coli to produce a recombinant aneroin protein, which was subsequently processed through wet- and electro-spinning. The resulting fibres exhibited excellent mechanical properties — superior to those of spider silk with a similar molecular weight. A novel marine silk fiber (named aneroin) from sea anemone has been discovered, and wet-spun and electrospun silk fibers from purified recombinant aneroins have been successfully fabricated. Aneroin fibers have promising mechanical properties, suggesting that this protein has potential for use as a novel fibrous biomaterial. Its use would expand the applications of silk in the development of multifunctional and bio-inspired materials.