Ultra-fast 3D printing of realistic organ models
Researchers at University of Buffalo refined the use of stereolithography for 3D printing of organ models containing living cells. Described in the newspaper Advanced health materials, the team’s technique is capable of printing models 10 to 50 times faster than the industry standard – in minutes instead of hours – marking a major milestone in the quest for organ creation. replacement 3D printed.
Conventional 3D printing involves the meticulous addition of material to the 3D model with a small needle which produces fine detail but is extremely slow, taking six or seven hours to print a model of a human part such as a hand, for example. The long process causes cellular stress and injury, inhibiting the ability to seed tissues with living, functioning cells.
The method developed by the Buffalo Group takes a different approach that minimizes damage to living cells. Funded by the U.S. National Institute of Biomedical Imaging and Bioengineering (NIBIB), the fast and cell-friendly technique is an important step towards creating imprinted tissues infused with large numbers of living cells.
Instead of a needle moving across a surface slowly building up the details of the 3D model, the team developed a system that allows a small 10cm model of a human hand to come out – quite dramatically – out. a vat of liquid in minutes. . The stereolithographic method uses light projected at the bottom of the tank which penetrates through the mixture of hydrogel and living cells. Light polymerizes the hydrogel / cell mixture at precise positions in the model, building entire layers of the model continuously, rather than one point at a time.
“This is an important step towards printing biologically active 3D fabrics,” said Dr. David Rampulla, director of the NIBIB program in synthetic biological systems. “This new technique combines a very cell-friendly hydrogel blend with the rapid printing process, which prevents cells from being suspended in a cell-damaging environment for an extended period of time. This combination allowed the team to introduce living cells into their 3D printed tissues, with the vast majority of cells remaining alive and functional.
With the goal of moving from small organ models to full-sized replacement organs in the future, the engineering team successfully used the new method to print tissues containing internal branching networks that mimic the blood vessels. As Associate Professor Rougang Zhao, team leader, noted, “Keeping the cells that lie deep in a full-sized imprinted organ alive is one of the many challenges in creating healthy organs. functional replacement. We found that our method worked well in terms of creating branching, vessel-like networks to facilitate the delivery of nutrients to cells embedded in the imprinted tissue.
Going further, the team introduced living endothelial cells into the branch channels of their 3D printed tissues. Endothelial cells adhere to the walls of the artificial vasculature and expand to form an endothelial lining similar to that found in real blood vessels.
The research team is now working to increase the size of printed tissues while maintaining structural integrity and cell viability. Their work is an important step towards the goal of one day printing replacement organs – a biomedical breakthrough that could save countless lives lost due to the widespread shortage of donor organs.