Fibroin is a natural protein that forms the structural basis of silk produced by certain insects, particularly silkworms. It is known for its strength, durability, and biocompatibility, making it a valuable material in various applications, including textiles and biomedical devices. The protein is composed of long chains of amino acids, which contribute to its unique properties. Fibroin can be processed into fibers, films, and scaffolds, and is often studied for its potential in tissue engineering and drug delivery systems due to its ability to support cell growth and integration.