First protein microfibre developed in lab

In a first, scientists have created new proteins that are capable of self-assembling into fibres on a microscale, paving the way for new opportunities for using engineered protein fibres in drugs.

"A microscale fibre that is capable of delivering a small molecule, whether it be a therapeutic compound or other material, is a major step forward," said lead researcher Jin Kim Montclare, associate professor at New York University.

For as long as scientists have been able to create new proteins that are capable of self-assembling into fibres, their work has taken place on the nanoscale.

Many materials used in medicine and nanotechnology rely on proteins engineered to form fibres with specific properties.

For example, the scaffolds used in tissue engineering depend on engineered fibres, as do the nanowires used in biosensors. These fibres can also be bound with small molecules of therapeutic compounds and used in drug delivery.

The researchers began their experiments with the intention of designing nanoscale proteins bound with the cancer therapeutic curcumin.

They successfully created a novel, self-assembling nanoscale protein, including a hydrophobic pore capable of binding small molecules.

To their surprise, after incubating the fibres with curcumin, the protein not only continued to assemble, but did so to a degree that the fibres crossed the diameter barrier from the nanoscale to the microscale, akin to the diameter of collagen or spider silk.

"This was a surprising and thrilling achievement," Montclare said, and explained that this kind of diameter increase in the presence of small molecules is unprecedented.

Biomaterials embedded with small molecules could be used to construct dual-purpose scaffolds for tissue engineering or to deliver certain drugs more efficiently.

The study appeared in the journal Biomacromolecules.