- Tram Ho
Creating human livers in the lab seems like a distant and scary idea. It makes you imagine the story of Dr. Frankenstein.
But a team of scientists from Brazil really want to do that. Recently, they used biological 3D printing technology to create " mini " livers that fully simulate the function of a human liver including building proteins, storing vitamins and secreting bile.
These liver cells are made up of stem cells that are cultured and reprogrammed. In the future, they are expected to help the health system solve two outstanding problems: serve drug trials and end transplant scarcity.
3D printed livers will revolutionize organ transplantation
Organoids will be the future of medicine
In recent years, the trend of organoids research has become more and more popular. Organoids are essentially a collection of organ tissues created from cell culture in a laboratory. Provided that some or all of its functions are performed, organoids are referred to as miniature organs.
Measuring from a few hundred micrometers to several centimeters, these small viscera are still able to simulate and imitate what an internal organ can do. That is why they are thought to be a factor that will help us soon revolutionize biological and medical research.
In their study, scientists from the Human Genome and Human Stem Cell Research Center (HUG-CELL) of the University of São Paulo (USP), Brazil, used human cells as birth cells. learn, and successfully print, the liver organoids.
These cells, originally, were blood cells collected from 3 volunteers. Through the 2012 Nobel Prize-winning reprogramming medicine of Japanese scientist Shinya Yamanaka, the blood cells were turned back into pluripotent induced stem cells (iPSCs).
Brazilian scientists then intervened to differentiate these stem cells into liver cells for printing. Typically, biological 3D printing uses only a needle with unicellular resolution. This means that only one cell can be released at a time.
But Brazilian scientists want to make an improvement. They grouped the stem cells into clusters before printing using a biological hydrogel. When printed in such clusters, the researchers found that the liver tissue was better connected and more durable than previous 3D printing methods.
These mini livers were also able to perform the function of real livers. " They were able to clean the toxins in the blood and secrete albumin [a protein that only the liver can produce]," said Ernesto Goulart, lead author of the study.
An organoids liver was previously created by culture. But now scientists can use 3D printing technology to create them.
Serve the drug test
The liver is a very special organ in the human body, because it is the only organ capable of regenerating itself. For example, a cancer patient may have surgery to remove up to three-fourths of his liver, but the remaining one-quarter of the liver can still recover and keep them alive.
The liver is also a complex organ, because it performs nearly 500 different functions in the body. It ranks second only to the brain in terms of busyness. The liver is involved in the digestion of food, turning food into energy and nutrients that cells can use.
It breaks down and neutralizes toxins that enter the body, releasing huge amounts of bio-chemicals, from hormones, enzymes to anticoagulants and immune molecules. The liver also controls many chemical components in the blood.
So when a liver goes wrong, it's going to be a big deal. Studying liver diseases requires a perfect laboratory model, and the animals' liver sometimes does not accurately reflect what happens in a human liver.
So scientists are putting their trust in mini-organs, organoids that can help them perform drug tests for many liver diseases, especially nonalcoholic fatty liver disease. (NAFLD).
NAFLD is determined by the accumulation of fat in the liver of people who drink little or no alcohol. If the condition progresses, their liver may develop cirrhosis and even liver failure similar to that of alcoholics.
Currently in the United States alone, about 80-100 million people are affected by non-alcoholic fatty liver disease. But how the disease progresses is still something scientists don't know yet.
Organoids appear like a new hope here. In several studies, scientists were able to create mini livers that mimic NAFLD. The liver cells used to make organoids have been modified to turn off a gene labeled SIRT1.
This gene is responsible for regulating fat storage and metabolism, so when they are deactivated, the mini-liver begins to accumulate fat around them similar to NAFLD patients. It turns yellow, and the fat concentration in each liver cell also increases.
After that, the fatty liver mini was tested for a drug molecule called resveratrol. In nature, resveratrol often appears as an ingredient in grapes and wines that enhance SIRT1 gene function.
When the scientists injected it into the fatty fatty liver, resveratrol actually reduced fat storage, implying it could become a drug for patients with NAFLD.
Until the transplant is complete
Certainly, when scientists create biological 3D-printed livers, their ultimate goal is to use them to transplant them to humans, patients with liver failure or liver resection because of a For some reason, cancer for example.
The 3D-printed liver uses the patient's own stem cells, so it eliminates the risk of rejection. Patients will not need to take anti-rejection medication every day for the rest of their lives. And above all, artificial livers can address the current shortage of organ donors.
Liver transplant patients now have to wait on average 150 days. Half of them certainly can't wait and will die.
In the United States alone, approximately 7,300 people die each year because they cannot find a suitable organ. Liver transplant patients now have to wait on average 150 days. Half of them certainly can't wait and will die.
In many cases, the only hope these patients have comes from the tragedy of another. For example, someone must be in a traffic accident and die, after that, their organs will be recovered to save the lives of patients who are waiting.
If the artificial liver can be 3D printed, it will solve all these problems. Goulart said he and his team are now planning to multiply their small livers to increase their size.
" We have made the liver on a small scale, but with the potential of this method, they can easily be replicated ," Goulart said.
" There are many stages that need to be completed before we can make a complete liver, but we are on the right track to achieving that promising result, " the scientists said in their paper. Their study published in Biofabrication magazine.
Another important advantage is that the 3D printing liver will have a zero probability of transplant rejection, if the cells used to make biological ink are the patient's stem cells, Mayana Zatz, a co-author of the study, said. .
" Not only can 3D-printed human liver stop ending the dependence on limited organ supplies, but they can even make liver transplants safer , " she said.
References Futurism, Theconversation
Source : Trí Thức Trẻ