Fast magnetic 3D printing of human cells

Imagine being able to see your doctor and instead of receiving a single treatment, you will receive a medication specifically tailored to your symptoms.

A team of engineers from McMaster University has found a way to use 3D printing technology to create artificial tumors to help researchers test new drugs and treatments, which could lead to personalized medicine.

Currently, for researchers to study human health, tests are very expensive and time consuming.

Disease research is usually done in the laboratory, for example by creating a single layer of human or animal cells (2D models) to test drugs and their impact on human cells. Alternatively, animal models are used to study the progression of the disease.

If realistic 3-D cell groups, with multiple layers of cells, can be produced to better mimic conditions inside the body, this can eliminate the use of animals during testing.

Led by Ishwar K. Puri, a professor of mechanical engineering and biomedical engineering, McMaster's team has come up with a new method using magnets to quickly print clusters of 3D cells.

To do this, the McMaster team used the magnetic properties of different materials, including cells. Some materials are strongly attracted or sensitive to magnets. Materials with higher magnetic susceptibility will feel a stronger attraction for a magnet and will move towards it. The weakly attracted material with lower susceptibility is moved to the lower magnetic field regions that move away from the magnet.

By designing magnetic fields and magnets carefully arranged, it is possible to use the magnetic susceptibility differences of two materials to focus one in a volume.

The team formulated bio-bonds by suspending breast cancer cells in a cell culture medium containing the hydrated magnetic salt, Gd-DTPA. Like most cells, breast cancer cells are much less attracted to magnets than Gd-DTPA, an FDA-approved, human-directed MRI contrast agent. Therefore, when a magnetic field is applied, the salt hydrate moves to the magnets, moving the cells to a predetermined area of ​​minimum magnetic field strength. This sows the formation of a group of 3-D cells.

Using this method, the team printed 3D cancer tumors in less than six hours. Tests have been performed to confirm that salt hydrate is not toxic to cells. They are now working on more complex bio-links to print clusters of cells that better mimic human tissue.

In the future, tumors containing cancerous cells could be rapidly created through 3D printing, and the reactions of these artificial tumors to rapidly tested drugs, with a multitude of experiments conducted simultaneously. The printing of human-like cell groups also offers a future path for 3D printing of multiple tissues and organs.

Their study titled "Rapid Magnetic 3D Printing of Cell Structures with MCF-7 Inks" was published in the February 4 issue of Research, a scientific partner newspaper.

"We have developed an engineering solution to overcome current biological limitations and it has the potential to accelerate tissue engineering technology and regenerative medicine," said Sarah Mishriki, Ph.D. candidate for the School of Biomedical Engineering and lead author. "The ability to quickly manipulate cells in a safe, controllable and contactless way allows us to create unique cell landscapes and microarchitectures in human tissue without using scaffolding."

"This magnetic method of producing 3D cell clusters brings us closer to the rapid and cost-effective creation of more complex models of biological tissue, accelerating discovery in academic labs and technological solutions for the industry," said Rakesh Sahu , research associate.

Provided by
McMaster University