3D Printed Organs: The Future of Transplantation

This type of regenerative medicine is still in its infancy, and the driving force behind this innovation is the “real human need,” Lewis said.

The reason for this discrepancy is “a set of people who have had catastrophic health events, but their organs are of insufficient quality for donation, or they are not on the organ donor list, and it is really difficult to find a very good match” so the patient’s body does not reject the transplanted organ.

Although live donors are an option, “surgery on someone who doesn’t need it” is a big risk, the doctor said. Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine. “So, because living donors aren’t usually the preferred way, then you’re getting someone else’s organ that needs it, especially as we get older.”

In 2006, Atala and his colleagues were responsible for manually growing human bladders in a laboratory and implanting a complex internal organ in humans for the first time – saving the lives of three children who had bladders.

According to the Department of Health Resources and Services, 17 people die every day waiting for an organ transplant. And every nine minutes, another person joins the queue, the agency said. In 2021, more than 90% of people on the transplant list needed a kidney.

“Nearly a million people around the world need a kidney, so they are in the final stages of kidney failure and they have to go on dialysis,” Lewis said. “After you go on dialysis, you have to live for almost five years, and your mortality rate increases by 15% every year. Dialysis is very difficult for your body. So it helps to solve this big problem of the print organs.”

“There are a lot of antihypertensive pills. Anyone who needs them can get them,” said Martin Rothblatt, CEO and chairman of United Therapeutics, at Life Itself, a health and wellness event in partnership with CNN. United Therapeutics is one of the sponsors of the conference.

“There is no practical reason for those who need kidneys – or lungs, heart, liver,” he added. “We’re using technology to solve this problem.”

Publications 101

To begin the process of biomarking the body, doctors usually start with the patient’s own cells. They get a small needle biopsy of the body or perform a minimally invasive surgical procedure that removes a small piece of tissue that is “less than half the postage stamp,” Atala said. “By taking this small piece of tissue, we can differentiate cells (and) grow and expand cells outside the body.”

This growth takes place in a sterile incubator or bioreactor, a pressure-resistant stainless steel container that helps the cells be nourished with a nutrient called “media,” which doctors feed them every 24 hours because the cells have their own metabolism, Lewis said. Each cell type has a different media, and an incubator or bioreactor acts as a furnace-like structure that mimics the body’s internal temperature and oxygenation, Atala said.

Then we mix it with this gel, which is like glue, – says Atala. “Every organ in your body has cells and the glue that holds them together. It’s basically called the ‘extracellular matrix.’

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This glue is the nickname of Atala’s bioinc, a printable mixture of living cells, water-rich molecules called hydrogels, and media and growth that help cells multiply and differentiate, Lewis said. Hydrogels mimic the extracellular matrix of the human body, which contains proteins, collagen and hyaluronic acid.

The non-cellular part of the glue can be made in the lab and “will have the properties of the tissue you are trying to replace,” Atala said.

Biomaterials used to prevent a negative immune reaction are usually non-toxic, biodegradable, and biocompatible, Lewis said. Collagen and gelatin are two of the most common biomaterials used to print tissues or organs.

Printing process

From there, doctors load each bioink into a printing chamber, depending on how many types of cells they want to print, “using a printing head and a nozzle to extrude the ink and layer the material,” Lewis said. . To create tissue with individualized properties, the printers were programmed with imaging data from the patient’s X-rays or scans, Atala said.

“With a color printer, you have several different cartridges, each cartridge prints in a different color and you find your (final) color,” Atala added. Bioprinting is the same; you’re just using cells instead of traditional inks.

The length of the printing process depends on several factors, including the organ or tissue being printed, the accuracy of the resolution, and the number of printing heads required, Lewis said. But it usually lasts a few hours. The time from biopsy to implantation is four to six weeks, Atala said.

At the Wake Forest Institute of Regenerative Medicine, a 3D printer injects different types of cells into the kidney bones.

The key is to “get the bodies to work as they should,” Lewis said.

“In order to get an organ from a donor, it is necessary to immediately insert the organ into a bioreactor and start perfusion, otherwise the cells will die,” he added. Perfusion is the supply of fluid, usually blood or blood substitutes, by circulating it through blood vessels or other channels.

Depending on the complexity of the organ, tissue sometimes needs to be reached in a bioreactor or further lead connections, Lewis said. “There are a number of plumbing issues and challenges for that printed organ to actually function like a human organ in vivo. In fact, it has not yet been fully resolved.”

Once a biopsy organ is implanted in a patient, it breaks down naturally over time – which is good because it is designed to work like this.

“You’re probably wondering,‘ Well, then what happens to the tissue? Will it split? ”“ No, really, ”Atala said.“ These glues will melt and the cells will feel the bridge loosen; they feel that they no longer have a firm foothold. In this way, the cells do what they do in their own bodies, creating their own bridges. their glue. ”

Other challenges

Atala and Lewis are conservative in their calculations of how many years are left before the implantation of fully functioning biomarkers.

“The field is moving fast, but I mean, we’re talking about a decade plus, despite all the tremendous progress,” Lewis said.

“I never learned to predict many years ago because you will always be wrong,” Atala said. “There are many factors in terms of production and (U.S. Food and Drug Administration regulations). Finally, our interest is, of course, to make sure that the technology is safe for the patient first and foremost.”

When bioprinting is an accessible option, accessibility should not be a problem for patients and their caregivers.

They will “definitely be available,” Atala said. “The cost of organ failure is very high. It costs more than a quarter of a million dollars a year to keep a patient on dialysis to keep a patient on dialysis. So it’s much cheaper to create an organ that you can do. Implant the patient.”

According to a study published by the American Society of Nephrology, the average cost of a kidney transplant in 2020 will be $ 442,500, and 3D printers will retail for several thousand to $ 100,000, depending on the complexity. But even with low-cost printers, the more expensive parts of bioprinting can include storing cell banks for patients, growing cells and safely handling biological materials, Lewis said.

Some of the main costs of existing organ transplants are “organ removal from the donor, transportation costs and then, of course, the recipient’s surgery, followed by all the care and monitoring,” Lewis said. “Part of that cost is that it will still play out, even if it’s bio-printed.”

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