Close-up of a tubular structure made by simultaneous printing and self-assembly of graphene oxide and a protein.
An international team of scientists, led by Alvaro Mata at the University of Nottingham and Queen Mary University London in the UK, has discovered a new material that can be 3D printed to create tissue-like vascular structures. In a paper in Nature Communications, the scientists report developing a way to 3D print graphene oxide with a protein that can organize into tubular structures that replicate some of the properties of vascular tissue.
"This work offers opportunities in biofabrication by enabling simultaneous top-down 3D bioprinting and bottom-up self-assembly of synthetic and biological components in an orderly manner from the nanoscale," said Mata. "Here, we are biofabricating micro-scale capillary-like fluidic structures that are compatible with cells, exhibit physiologically relevant properties, and have the capacity to withstand flow. This could enable the recreation of vasculature in the lab and have implications in the development of safer and more efficient drugs, meaning treatments could potentially reach patients much more quickly."
Self-assembly is the process by which multiple components spontaneously organize into larger, well-defined structures. Biological systems rely on this process to controllably assemble molecular building blocks into complex and functional materials exhibiting remarkable properties such as the capacity to grow, replicate and perform robust functions.
The new biomaterial is produced by the self-assembly of a protein with graphene oxide. This self-assembly process allows the flexible (disordered) regions of the protein to order and conform to the graphene oxide, generating a strong interaction between them. By controlling the way in which the two components are mixed, it is possible to guide their assembly at multiple scales in the presence of cells to produce complex robust structures.
The material can then be used as a 3D printing bio-ink to print structures with intricate geometries and resolutions down to 10mm. The research team have demonstrated the ability to build vascular-like structures in the presence of cells that exhibit biologically relevant chemical and mechanical properties.
"There is a great interest to develop materials and fabrication processes that emulate those from nature. However, the ability to build robust functional materials and devices through the self-assembly of molecular components has until now been limited," said team member Yuanhao Wu, who is also at the University of Nottingham and Queen Mary University London. "This research introduces a new method to integrate proteins with graphene oxide by self-assembly in a way that can be easily integrated with additive manufacturing to easily fabricate biofluidic devices that allow us to replicate key parts of human tissues and organs in the lab."