In a quest to find ways to protect easily degradable, sensitive molecules that have potential health or nutritional benefits, scientists at the University of Cambridge have come up with a way to mimic nature and accomplish their goal.
The study argues that sealing such molecules in a protective layer of silk could be the answer, the researchers successfully showed that silk micrococoons can increase the stability and lifetime of an antibody.
The scientists have designed what are microscopic versions of the cocoons spun by silkworms. The capsules made with a specially-developed microengineering process mimics the silkworm spun cocoons and comprises a solid and tough shell of silk nano-fibrils that surround and protect a centre of liquid cargo; and also are about a thousand times smaller than those created by silkworms.
“It is a common problem in a range of areas of great practical importance to have active molecules that possess beneficial properties but are challenging to stabilise for storage” said Professor Tuomas Knowles, who led the study. “A conceptually simple, but powerful, solution is to put these inside tiny capsules. Such capsules are typically made from synthetic polymers, which can have a number of drawbacks, and we have recently been exploring
the use of fully natural materials for this purpose. There is potential to replace plastics with sustainable biological materials, such as silk, for this purpose.”Dr. Chris Holland, co-worker and head of the Natural Materials Group in Sheffield added: “Silk is amazing because whilst it is stored as a liquid, spinning transforms it into a solid. This is achieved by stretching the silk proteins as they flow down a microscopic tube inside the silkworm.”
“Natural silk is already being used in products like surgical materials, so we know that it is safe for human use. Importantly, the approach does not change the material, just its shape.” Professor Fritz Vollrath head of the Oxford Silk Group said iterating how silk is not only easier to produce; it is also biodegradable and requires less energy to manufacture.
To explore the viability of silk microcapsules in this regard, the researchers successfully tested the micrococoons with an antibody that has been developed to act on alpha-synuclein, the protein that is thought to malfunction at the start of the molecular process leading to Parkinson’s Disease.
“By containing such antibodies in micrococoons, as we did here, we could significantly extend not just their longevity, but also the range of antibodies at our disposal,” Knowles said. “We are very excited by the possibilities of using the power of microfluidics to generate entirely new types of artificial materials from fully natural proteins.”
