CnN's June 10 website titled "When Will We Be Able to 3D Print Organs?" Who can afford it? " by Christen Rogers. The full text is excerpted below:
What if doctors could print kidneys from patients' cells without having to look for matching donor organs and worry about being rejected by the patient's body?
Professor Jennifer Lewis of Harvard's Weis Institute for Bioengineering says that with the help of bio-3D printing technology, this wish could be realized as soon as a decade. According to the study, organ bioprinting is the use of 3D printing technology to assemble multiple cell types, growth factors and biological materials layer by layer to create artificial organs that perfectly mimic natural organs.
Lewis said that this regenerative medicine is in the research and development stage, and the driving force behind it is "the real needs of human beings."
Desperate to wait
According to the U.S. Health Resources and Services Agency, as of June 10, there were 106,000 adults and children on the U.S. national organ transplant waiting list. However, the average number of organs provided by living donors is only about 6,000 per year, while about 8,000 deceased people donate organs each year, with an average of 3.5 organs provided by one deceased.
Dr. Anthony Atala, from wake-up Forest University's School of Regenerative Medicine, said that while living donors are one of the options, "operating on people who don't need surgery" is highly risky. "Kinship donation is usually not the preferred method because doing so is to take the organ from the body of someone who may need it later," he said. ”
According to the Health Resources and Services Agency, 17 people die every day while waiting for transplanted organs. In 2021, more than 90% of people on the transplant list will need a kidney.
Lewis said: "About 1 million people around the world need kidneys. They reach the end of renal failure and must undergo dialysis. Dialysis places a great burden on the body, and with each passing year, the patient's chance of dying increases significantly. Therefore, the motivation to solve the major challenge of organ 3D printing is really great. ”
Martina Rothblatt, CEO and chairman of United Therapeutics, said: "We are using technology to solve this problem. ”
Magical ink
To turn on the process of bioprinting organs, doctors usually start with the patient's own cells. Atala said they performed a small needle biopsy of an organ, or performed minimally invasive surgery, removing a small piece of tissue that was "less than half the size of a stamp." "Using this bit of tissue, we were able to take the cells out and continue to grow them in vitro." He said.
The culture is carried out inside a sterile incubator or bioreactor, a pressurized stainless steel vessel that helps cells get enough nutrients, Lewis said. Doctors feed them nutrients (medium) every 24 hours because the cells have their own metabolism. Depending on the cell type, so do the nutrients required.
Atala said: "Then we mix it with a gel that is like a glue. Every organ in your body is made up of cells and glue that sticks them together. ”
Lewis said glue is Atala's nickname for bioink, a printable mixture whose composition includes living cells, water-rich molecules called hydrogels, culture media and growth factors that help cells continue to proliferate and differentiate. The hydrogel mimics the body's extracellular matrix— it contains substances such as proteins, collagen, and hyaluronic acid.
Atala said the other components of the glue can be made in the lab except for cells, and that it "will have the same properties as the tissue you're trying to replace."
The biomaterials commonly used must be non-toxic, biodegradable and biocompatible to avoid an adverse immune response, Lewis said. Collagen and gelatin are the two most commonly used biomaterials when bioprinting tissues or organs.
Witness moments of wonder
Doctors then load each bioink — the type of ink depends on how many cell types they want to print — into a print box, "extrude the bioink with the print head and nozzle, and pile up the material layer by layer."
Atala said the patient's X-ray or scanned image data could be fed into a printer to print out tissue with personalized characteristics. "A color printer has several cartridges of different colors that [eventually] blend the color you want." The same goes for bioprinting; It's just that cells are used instead of traditional ink.
Lewis said the length of time required for the printing process depends on several factors, including the type of organ or tissue to be printed, the resolution and the number of print heads required. But usually lasts for several hours. Atala said the entire process, from biopsy to implantation, takes about 4 to 6 weeks.
The ultimate challenge, Lewis says, is to "get the organs to function as they should," and doing so is tantamount to getting the "Holy Grail."
She added: "Just like when picking an organ from a donor, you have to immediately put the organ in a bioreactor and start perfusing or the cells will die." "Perfusion is the provision of fluids (usually blood or blood substitutes) to an organ to circulate through blood vessels or other channels.
Depending on the complexity of the organ, lewis said, sometimes it is necessary to further mature the tissue in a bioreactor or facilitate the connection of the corresponding site. "To make this printed organ function properly in the body like a natural organ, there are some 'pipe unclogging' problems and challenges that need to be solved," she said. These issues have not yet been fully resolved. ”
Bioprinted organs, when implanted in patients, naturally degrade over time – that's okay, that's what we expected.
Atala said, "So, what happens to the organization next?" Will it fall apart? No. The glue will dissolve, the cell will feel the 'bridge' collapsing; the cell will feel that its foundation is no longer solid. As a result, cells will create their own bridges and glues in your body. ”
Affordable price
In estimating how many years it would take to implant a functioning bioprinted organ into the human body, Atala and Lewis were conservative.
Lewis said: "I think it will be a decade from now, although we have made the significant progress mentioned above. ”
According to Atala, "There are too many influencing factors when it comes to manufacturing and regulation. Of course, it is first and foremost to ensure that these technologies are safe for patients. ”
Whenever bioprinted organs become a reality, whether patients and their families can afford them should not be in question.
Atala said their costs were "certainly affordable." "The costs associated with organ failure are very high, costing $250,000 a year to get just one patient on dialysis. Therefore, it is much cheaper to make an organ that can be implanted in a patient's body. ”
Data released by the American College of Nephrology shows that kidney transplants cost an average of $442,500 in 2020 — while retail prices for 3D printers range from thousands to $100,000, depending on their complexity. But lewis said that while low-cost printers are available, the expensive aspects of bioprinting include maintaining cell banks for patients, culturing cells, and safely handling biomaterials.
Lewis said the main costs of an organ transplant at the moment include "getting the organ from the donor, the cost of transportation, then the transplant, and all the care and monitoring." Some of these costs will still exist, even if the organ is 3D printed."
Source: Reference News Network