Sea anemone-derived repeat protein development for tissue engineering application

초록

The silk has been used as a novel texture for centuries, and is now being widely used in medical engineering fields such as suture and surgical scaffold. Its biocompatibility, slow biodegradability, self-assembly, and controllable structure have allowed silk as a promising biomedical material. However, applications and research of silk have narrowly been focused on silkworms and spider silks, neglecting species’ variability in material properties. Considering that the spider silk has higher mechanical modulus, compared to the silkworm silk, based on more crosslinks generated from its cystein residues, it is worth to investigate diverse silks in nature to engineer superior properties in material. In the present work, the new silk-bearing marine organism (sea anemone) was genetically redesigned and engineered for desired medical usages, requiring mechanical extensibility and durability. Inspired by the sea anemone’s behavior which varies in length from 0.5 cm to over 10 cm, we found the elastic silk-like motifs mainly located in its extensible tentacle and skin. The motifs were repeated and bio-synthesized as a protein named of ‘Aneroin’. The aneroin was fabricated into diverse forms including nano sheets, micro fibers, hydrogels and 3D bio-inks that meet mechanical property requirements of artificial organs. The aneroin fiber has competable modulus with natural mammalian tendon collagen, and aneroin hydrogel was 10-fold stiffer than mammalian cardiac or skeletal muscle. The 3D-printed aneroin constructs presented precisely controlled geometries in human organ constructs (e.g. actual-sized human ear, vascular graft, and nose). The scaffolds were also beneficial for facilitating cell proliferation and differentiation. The results showed that the aneroin based silk material has a high potential of biomedical materials, which for cell-containing patches, biomolecule carriers, bioartificial organs and three-dimensional space-filling materials.