Bioskiving helps Tufts researchers work on collagen

Fabricating collagen structures that maintain the collagen's natural strength and fibre structure for biomedical applications is one of the recent developments in skin technology. As skin is the most abundant tissue, so is collagen the most abundant protein in the body. Since it is biocompatible and biodegradable, scientists use it extensively in building scaffolds for tissue engineering. The setback in collagen is that in its natural form it is insoluble in water. Processing techniques affect the material’s strength and disrupt its fibrous structure.

Researchers at Tufts University School of Engineering have found a new technique, called bioskiving to create collagen structures from thin sheets of decellularised tendon stacked with alternating fiber directions that maintain much of collagen's natural strength.

Bioskiving, they have found, does not dilute collagen's natural properties. “Our method leverages collagen's native attributes to take advantage of the well-organised micro/nanostructures that nature already provides,” says Qiaobing Xu, assistant professor of biomedical engineering, and inventor of the new technique.  

Mr Xu and Kyle Alberti, a Ph.D. student in Xu’s lab, described their technology in the paper "Slicing, Stacking and Rolling: Fabrication of Nanostructured Collagen Constructs from Tendon Sections" published online in Advanced Healthcare Materials.

In their research, both Xu and Alberti cut small sections of collagen from bovine tendons. Using a specialised detergent, the researchers decellularised the sections, leaving intact only the extracellular collagen matrix made of bundles of aligned collagen nanofibers.

They sliced the sections into ultra-thin sheets using a microtome, and then stacked 10 slices, crisscrossing the sheets so that the fibers in one ran perpendicular to those above and below it. This process produced a scaffold material with tensile strength stronger than constructs made using common processing techniques.

The researchers also created tubular scaffolding by rolling layers of collagen sheets around Teflon-coated glass rods. The sheets were layered so that fibers ran along the length and the circumference of the rods. This process yielded tubes that were found to be stronger than similar tubes made of reconstituted collagen. They also maintained their highly aligned fiber structure.

“Alignment gives the scaffold the ability to guide the direction and orientation of cell growth," says Mr Xu, who also has a faculty appointment at Tufts School of Medicine, "This capability is beneficial for tissue engineering applications where biocompatibility and the ability to guide unidirectional nerve growth are both desired, such as prosthetic or tissue engineering-baAir Foamposite One