Scientists have managed to design microscopic silk capsules that mimic on a microscopic scale the structure of silkworm cocoons. The capsules can serve as a protective environment for the transport of sensitive “cargo” such as natural silk proteins, antibodies or other delicate molecules. The collaborative research – which was performed by an international team of academics from the Weizmann Institute of Science in Israel; the Universities of Cambridge, Oxford and Sheffield in the UK; and the ETH in Switzerland – may lead to a host of applications in the cosmetics, food and pharmaceutical industries, particularly in the delivery of drugs within the body. The findings were reported in Nature Communications.
Researchers have been using chemically processed silk fibers. The use of natural proteins from which silkworms and spiders spin their elastic fibers has been limited as these proteins have a tendency to clump together once extracted. Dr. Ulyana Shimanovich, head of a new lab in Weizmann Institute's Materials and Interfaces Department, explains: “Making synthetic capsules is normally a complex and energy-intensive process. In contrast, silk capsules are easier to produce and require less energy to manufacture. Moreover, silk is biodegradable.”
The tough silk capsules may be used to protect sensitive molecules, such as antibodies and other proteins, preventing them from losing desired qualities. The capsules can be employed, for example, to deliver drugs or vaccines intact to target organs. In particular, says Shimanovich, they may help develop future therapies for neurodegenerative diseases: Because the capsules can penetrate the blood-brain barrier, they may enable the development of new treatment for these diseases. And because the capsules are biodegradable, they are likely to have multiple uses.