First protein microfibre engineered

Researchers have engineered the first protein microfibre which is capable of delivering a small molecule, whether it be a therapeutic compound or other material.
Researchers at the New York University Polytechnic School of Engineering have broken new ground in the development of proteins that form specialised fibres used in medicine and nanotechnology.
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.
For the first time, this achievement has been realised on the microscale - a leap of magnitude in size that presents significant new opportunities for using engineered protein fibres.

Jin Kim Montclare, an associate professor of chemical and biomolecular engineering at the NYU School of Engineering, led a group of researchers who set out to design 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.

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," said Montclare, explaining that this kind of diameter increase in the presence of small molecules is unprecedented.

"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," she said.
Montclare said that biomaterials embedded with small molecules could be used to construct dual-purpose scaffolds for tissue engineering or to deliver certain drugs more efficiently, especially those that are less effective in an aqueous environment.
Using microscopy, the team was able to observe the fibres in three dimensions and to confirm that the curcumin, which fluoresces when bound to structural protein, was distributed homogeneously throughout the fibre.
Despite the enormity of the jump from nano- to microscale, the research team believes they can devise even larger fibres.

The next step, Montclare said, is developing proteins that can assemble on the milliscale, creating fibres large enough to see with the naked eye.
The research was published in the journal Biomacromolecules.