Nan Fung-backed biotechnology developer Bolt Threads has already secured close to $57m in a series D round it aims to close at $106m.

Bolt Threads, a US-based high-performance fabrics developer backed by conglomerate Nan Fung, is seeking $106m in series D funding, according to a regulatory filing.

The company had secured $56.8m as of October 23, and TechCrunch identified venture capital firms Formation 8 and Foundation Capital as participants in the round.

Founded in 2009 as Refactored Materials, Bolt Threads is creating spider silk at industrial scale using microorganisms in order to create highly durable textiles. The material is stronger than…