Bone-on-a-chip device could lessen need for animal experiments

Engineers have developed a bone-on-a-chip device that grows human bone tissue in the laboratory, an advance that could reduce the need for tests on animals in medical research.

New technology uses mini scaffolding - three dimensional structures capable of growing human tissue in a lab (Image: Sheffield University)

In a paper published in Frontiers in Bioengineering and Biotechnology, the researchers – led by Sheffield University’s Department of Materials Science and Engineering and the Insigneo Institute for in silico Medicine - demonstrate how the bone-on-a-chip, which contains living cells, can be used to grow bone tissue which can then be used to test new potential treatments for diseased or damaged bones.

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Testing new medicines usually requires extensive in vivo assessments that involve animals, but the new approach has been developed in vitro - entirely in the laboratory - and reduces the need to use animals in research.

According to Sheffield University, the field of organ-on-a-chip aims to create small devices that contain miniature versions of organs such as bone, liver or lungs in the laboratory. By testing new medicines on small versions of human organs rather than in animal models, the hope is that there will be a higher success rate of finding ones that work in humans.

The eventual aim is for the Sheffield team’s device to connect to other organ-on-a-chip devices to create a human-on-a-chip that would remove the need for animal research when developing new medical treatments.

In vitro testing of new treatments is normally done on cells grown on flat, two-dimensional surfaces. However, the team of researchers has created three-dimensional scaffold structures within their bone-on-a-chip that better resembles real bone.

The three-dimensional structures are developed using polymerised high internal phase emulsion (polyHIPE) and emulsion templating. A polyHIPE is made using an oil that solidifies under ultraviolet light to create a plastic material which contains millions of tiny, interconnected holes. These highly porous materials form a scaffold that helps cells create new bone tissue in 3D.

Having produced the three-dimensional scaffolds, the team inserted them into a mini bioreactor to create the bone-on-a-chip device and used in vitro techniques to assess its potential to grow human bone tissue from stem cells.

In their paper, the researchers present findings demonstrating that organ-on-a-chip technologies have the potential to transform pharmaceutical pre-clinical testing by increasing throughput whilst minimising financial and ethical concerns associated with animal research.

In a statement, Dr Frederik Claeyssens, Reader in Biomaterials from the Sheffield University’s Department of Materials Science and Engineering, said: “The introduction of microfluidic channels in a porous material allows us to mimic the natural 3D environment of cells better than in standard microfluidics.

“This is, in my view, a great enabling technology to build complex 3D tissues - or organs-on-a-chip - as testing platforms for pharmaceutical testing.

“These platforms have the potential to reduce the time and effort required for, and also reduce the use of animal models for preclinical drug testing.”

The bone-on-a-chip research was conducted in collaboration with researchers from the Universitat Ramon Llull, Spain.