In Brief
Harvard researchers have developed a method for bioprinting stronger structures in the form of thick tissue. The method also embeds vascular systems within the tissue to allow it to survive longer and integrate within the body.

SUSTAINING AN ORGAN

Bioprinting makes it possible for scientists to make organs for transplants in a lab; however, it is a process that is marred by technical difficulties. Whether inside or outside of the human body, 3D printed cells require a complex system of nutrition or they die.

Now, a team of researchers from Harvard has published a paper in Proceedings of the National Academy of Sciences that reveals a method for bioprinting stronger structures that solves some of these problems. Ultimately, the team has managed to fabricate tissue that lives for an extended period and is 10 times stronger.

“This latest work extends the capabilities of our multi-material bioprinting platform to thick human tissues, bringing us one step closer to creating architectures for tissue repair and regeneration,” says Jennifer A. Lewis., senior author on the study.

Notably, the tissue survived up to six weeks, a spectacular length of time in bioprinting, by using vascular systems including both living cells and extracellular materials. The team stated that their new approach can be used to print thick tissues and can utilize other biomaterials, such as fibrin and hyaluronic acid.

So far, the team has successfully bioprinted tissue that is one centimeter thick. They were able to pump bone growth factors through the tissue to cause the development of cells in a four-week duration.

BUILDING UP TISSUES

The new bioprinting process uses a customized silicone mold as a vehicle for housing and building in the vascular systems. The researchers printed the network of vascular channels, and then they added a layer of live stem cells over that. With each layer, the structure grows and, through this process, becomes strong enough to ‘live.’

 

Since the researchers utilized silicone molds, it also means that the method can be adapted to create tissues of varying shape, width, and composition. This would allow the method to be used to build functioning tissue that can be integrated with blood vessels in the body to allow it to survive.

The results hold promise for resolving the problems facing the need for organ donors, as organ fabrication would remove the need for long transplant waiting lists.