Unexpectedly, “Second Brother” is really a treasure boy.
Shenzhen Translation Bureau is its compilation team, focusing on technology, business, workplace, life and other fields, focusing on introducing new foreign technologies, new perspectives, and new trends.
Editor’s note: It is reported that 20 people die awaiting organ transplants every day. Data show that there are currently more than 113,000 people in the United States waiting for transplant surgery, compared with 36528 transplant operations in 2018. More and more people, far more than the number of available organs. But technological advances provide a glimmer of hope for solving this problem. Genetically modified pigs may help humans write a new chapter in medical achievements. This article is translated from medium, the author of the article is Emily Mullin, and the original title is Surgeons Transplanted Living Pig Skin Onto Humans for the First Time span> .
Image source: Minipigs / Wikimedia Commons p>
Grafton, Mass. is a small town about 40 miles west of Boston. There is a pathogen-free facility in the town that is primarily responsible for genetically engineering experimental mini pigs that provide skin to humans.
The skin of these mini pigs looks very similar to human skin and is called Xeno-Skin. To speed up the healing process, surgeons at Massachusetts General Hospital will transplant the skin of these pigs into a small group of burn patients. This is the first experiment approved by the US Food and Drug Administration (FDA) to use living animal tissues in humans, a necessary step in transplanting entire organs grown in animals to people who need them This process is called xenotransplantation.
As we all know, the need for these organs is very urgent. Every day, 20 people die in the waiting span> of an organ transplant. According to government data, the United States currently has 11.3More than 10,000 people are waiting for transplant surgery, and there were only 36,528 transplant operations in 2018. As a result, more and more people wait for transplants each year, far exceeding the number of available organs. For decades, researchers have been using animal donors as a way to alleviate this chronic shortage, but organ transplants from animals often fail.
It can be said that the xenotherapeutics developed by Boston-based biotechnology company XenoTherapeutics has a bright future. So far, one patient has received a genetically modified pig skin transplant, and five more burn patients are awaiting transplantation. These skins are only temporarily transplanted into the human body and will be removed once the patient’s skin has grown. Doctors participating in the trial said that the donor tissue seemed to be healing, and that the skin of the human body receiving the transplant was also healing, and there was no rejection during the process, such as triggering an immune response or transmitting animal viruses. These two problems are xenotransplantation. The main problems faced. Aul Holzer, CEO of XenoTherapeutics, told OneZero: “We are moving towards the goal of fully replicating the standard of care skin for severe and large burns.” P>
In general, severe second- and third-degree burns are treated with the skin of an allogeneic or human corpse. Allografts help protect the wound from infection, prevent the loss of body fluids from the body, and promote the re-growth of the patient’s skin. Dr. Curtis Cetrulo, a plastic surgeon at the Massachusetts General Hospital and former chairman of the board of XenoTherapeutics, said: “Skin is an important barrier to everything in the world. As humans, we are like a bag of liquid, and our skin is like a plastic bag The same. “ P>
Since human skin can survive for a while, this is why it can be preserved in humans and pigs and transplanted to patients. But like other organs, cadaver skin is expensive, and because there are not enough donors, it is difficult to obtain it from the national skin bank. The skin bank has strict standards and cannot accept donor skin from cancer or viral infections such as HIV and hepatitis, as these diseases have the potential to spread to transplant recipients. Some skin banks also limit the age of skin donors.
Holzer said that when skin from corpses is lacking-especially in battlefields and developing countries-pig skin may be an alternative. The skin of pigs and other animals has been used for wound dressings, but these skins have been chemically treated and are dry skin, so there are no more living cells in these skins. “It’s basically like a piece of leather,” Cetrulo said. “It’s dead skin, it’s processed skin.” P>
Xenogeneic skin is made of living tissue, and is designed to promote blood flow or blood vessel growth, a key step in the healing process that helps fight infections. First placeThe report said that they transplanted the heart of a genetically modified pig in a baboon and survived for an average of more than a year. One of the baboons lived for more than two and a half years, breaking previous records of heart transplants from pigs to primates.
Gene editing tool CRISPR also makes it easier to modify animals for xenotransplantation. In 2017, a startup called eGenesis announced that they had successfully removed a group of viruses found only in pigs, which have long been considered to pose a risk of infection in humans when they undergo a swine organ transplant. Porcine endogenous retroviruses (PERVs) are considered to be another major “stopper” that hinders transplantation to human organs. Although no one has developed a PERV infection due to transplantation, laboratory studies have not yet concluded on this.
Dr. Megan Sykes, director of the Center for Translational Immunology at Columbia University, said: “Most people in the xenograft community now claim that the risk is manageable. The fact that the Food and Drug Administration approved the trial also reflects That idea. “ P>
Like their “predecessors,” pigs used for heterogeneous skin research must first be genetically engineered to prevent transplant rejection. But it may take years to see the first pig organ transplanted into a human.
“We have to make sure that the transplantation of skin or other non-lethal tissue is successful,” Ardehali said. “Next we can try the kidney, because if the kidney fails, the patient can still survive by dialysis, but if the heart Or lung failure, I’m afraid God can’t save you. “ P>
However, even if the technical issues are resolved, persuading the public to accept pig organ transplants can be a very difficult problem. Mohiuddin, now the director of the Heart Transplant Program at the University of Maryland School of Medicine, said that although xenotransplantation has great prospects and great potential, changing public opinion may be a long-term process.
Mohiuddin said: “If you tell someone, ‘We want to implant a pig’s heart in you,’ it can cause uproar. If the test is successful, it will pave the way for other types of transplants, such as kidneys, heart, lung Or liver. “ P>
One of the original uses of organ xenotransplantation may be so-called bridge transplants, in which patients need an organ to sustain a period of life, such as weeks or even months, until they can donate from humans To obtain more suitable organs. “But I believe that once we have the ideal pig donors and the organs they provide survive longer, we don’t need to replace them with new human organs.” P>
At the same time, XenoTherapeutics is developing nerves in genetically modified pigs that can be transplanted toPeople with nerve damage from a car accident, fall, or other injury. The company hopes to begin clinical trials of this method in 2020.
Ardehali said that in the next 5 to 10 years, people who need organ transplants will still be less likely to choose to transplant a pig’s heart or lung, but he does think that this situation is getting closer.
He said: “We have maintained great enthusiasm for many years, but it has not yet become a reality. Are we writing a new chapter in the history of human medicine? I don’t know, but it actually requires a major leap of faith. “ P>
Translator: Hi Soup p>