1 Introduction

Gene-editing tools like CRISPR have changed the way scientists work with DNA and can make very precise changes to an organism's genes, and one of those changes is organ transplantation. Scientists are trying to use animal organs that have been edited so they can work in humans. This could help solve the big problem of not having enough human organs for people who need them (Kohn et al., 2016; De Graeff et al., 2019). By altering the genes of animals, experts hope to create organs that the human body will not easily reject. This means that transplants will work better and patients may not need as many drugs to stop the immune system from attacking the new organ (Kohn et al., 2016).

The technique could help many patients, but it also raises ethical questions. Some people worry about how to treat these animals and whether it is right to change their genes for human use. Others worry about possible risks or what could happen to the environment (Capps, 2019; De Graeff et al., 2019; Devolder and Eggel, 2019). Editing animals in a way that makes them feel less distressed may be in line with certain animal welfare laws in Europe. However, there are also different ideas, arguing that this thinking does not respect the value of animals as living things (Devolder and Eggel, 2019).

The rules for gene editing are still being worked out, and they vary from country to country. The case of a gene-edited baby in China shows the need for stronger laws and better supervision (Li et al., 2019; Savulescu and Singer, 2019). In the UK, a new law called the Genetic Technology (Precision Breeding) Act is seeking to update the rules for editing the genes of animals (Palazzani, 2023). Around the world, most people agree that the public understands the technology and that clear rules are needed to use gene editing in a safe and fair manner (Camporesi and Cavaliere, 2016; Capps, 2019; Mandrioli, 2021).

This study will explore the medical benefits, ethical issues and rules of using gene-edited animal organs for human transplantation. This study examines key points in these areas and discusses possible ways to address the challenges. This study aims to help people better understand this topic and find a good balance between science and ethics when using this new technology.

2 Application of Gene Editing Technology in Xenotransplantation

2.1 How gene editing technologies (like CRISPR) improve animal organ compatibility

Gene editing tools, particularly CRISPR/Cas9, allow scientists to make very precise changes to an animal's genes. This is a big step forward for xenotransplantation because it helps make animal organs more suitable for use in humans. For example, CRISPR can be used to remove certain genes in pigs that cause a strong immune response in humans, known as hyperacute rejection. When these genes are removed, the body is less likely to reject the organ immediately (Fung and Kerridge, 2016; Eisenson et al., 2022).

CRISPR can also be used to put human genes into animals. This helps animal cells display human-like proteins on their surfaces, making it harder for the body's immune system to recognize them as foreign. These changes can improve the success rate of transplantation. In the future, it may even be possible for scientists to create animal organs that are almost identical to human organs (Liu et al., 2020; Zeng, 2023).

2.2 Successful cases of gene-edited animal organ transplants

In recent years, there have been some successful cases of animal organs being transplanted into humans. To date, three pig-to-human transplants have been reported: two kidney transplants from brain-dead patients, and a heart transplant in a clinical study. These cases show that gene-edited animal organs can work in humans, but there are still some problems such as long-term survival and immune rejection to be solved (Eisenson et al., 2022).

In another case, gene-edited pig islet cells were transplanted into patients with type 1 diabetes. These cells help patients reduce or stop using insulin for a period of time. This suggests that gene-edited animal tissue can help treat certain diseases, but more research and trials are needed, and some of the findings are very meaningful (Fung and Kerridge, 2016).

2.3 Reduce immune rejection and virus risk

Gene editing helps reduce the chances of immune rejection. Scientists can remove or alter parts of an animal's DNA that constitute substances that the human immune system considers a threat. For example, CRISPR can delete the gene in pigs that produces alpha-gal sugar, which normally causes strong rejection in humans, and removing the gene for this sugar can reduce the likelihood of rejection and improve the chances of successful transplantation (Fung and Kerridge, 2016; Eisenson et al., 2022).

Gene editing can also help address the risk of viruses. A big problem with xenotransplantation is that viruses from pigs can infect humans. A virus called PERV (Porcine Endogenous retrovirus) is of particular concern. Scientists have used CRISPR to turn off these viral genes in pigs, which makes pig organ transplants safer and brings us closer to using them more widely in medicine (Fung and Kerridge, 2016; Zeng, 2023).

3 Ethical Controversies on Animal Rights and Welfare

3.1 Do animals have the right to avoid genetic changes?

Whether animals have a natural right not to be genetically modified by humans, some people believe that animals should not change their genes because it will harm their natural state. Some say that animals should be treated with respect and not as tools for human use (De Graeff et al., 2019; Thom et al., 2022).

On the other hand, some people think gene editing is OK if it helps humans. Using animal organs in transplants may save lives and reduce pain, and from this perspective, the benefit to humans is more important than the harm to the animals. This is a better way of thinking (Johnson, 2022; Thom et al., 2022).

3.2 Animal welfare: pain and ethical checks in gene editing

Animal suffering is a big problem in gene editing and experimentation. The process often causes pain and stress to the animals. Despite regulations to reduce the condition, millions of animals suffer every year. Ethical reviews must therefore look closely at whether such experiments are really needed and whether they can reduce animal suffering (Devolder and Eggel, 2019; Johnson, 2022).

One way is to change the animals so they feel less pain. It might hurt them less. While this may be a good solution and in line with the regulations to protect animal welfare, it also creates new problems. Whether it is right to deprive animals of the ability to sense pain and whether it leads to more problems later (De Graeff et al., 2019; Devolder and Eggel, 2019).

3.3 Science vs. animal rights–what does society think?

Science, especially xenotransplantation, can lead to huge advances that help address the shortage of human organs, but such advances often use animals and raise ethical questions. There is a real tension between doing more research and being kind to animals, and finding a good balance is difficult (Johnson, 2022; Thom et al., 2023).

Public opinion is also important, and the public's views on gene-edited animal organs depend on their values, culture, and how they view the risks. Often, the public thinks differently from the experts. That's why it's important to bring more people into the discussion. Not just scientists and ethicists, but ordinary people as well, can help shape more equitable and socially acceptable policies (De Graeff et al., 2019; Johnson, 2022).

4 Social Justice and Ethical Issues

4.1 Could high transplant costs lead to social inequality?

The cost of using gene-edited animal organs for transplants is very high. This could exacerbate social inequality, and since it costs a lot of money to develop and use the technology, patients may also have to pay a lot, meaning that only the rich can afford it, while those with lower incomes may not. This may make the gap between rich and poor even wider (Reese et al., 2023; Thom et al., 2023). In addition, these expensive treatments can tie up significant medical resources, making it more difficult for others to access basic care.

If this advanced technology is only available to a small number of people, many others may be left behind. In theory, everyone should have the same opportunity to benefit from medical technology, no matter how much money they have. But without efforts to make it cheaper and more accessible, such transplants could become something only available to the wealthy, worsening social inequality (Figure 1) (Johnson, 2022; Reese et al., 2023).

Figure 1 Engineering equity into xenotransplantation through the spectrum of translational science. FDA, Food and Drug Administration (Adopted from Reese et al., 2023)

4.2 Public acceptance of gene editing and xenotransplantation

In order for these technologies to work in real life, the public needs to accept them, but many people have ethical or cultural concerns. Some people do not like the use of animal parts on humans due to religious, cultural or personal beliefs. This can make people reject the idea and slow its development (Loike and Kadish, 2018; Transfer, 2020). Therefore, it is very important to have a clear dialogue with the public and give good education to help the public understand how this technology works and why it works.

There are also concerns about long-term risks, such as the possible transmission of disease from animals to humans. These concerns need to be taken seriously. Clear communication about safety steps, rules, and ethics can help people feel safer. Talking to and listening to different groups in society can also help the public accept these new ideas (Rollin, 2020; Entwistle et al., 2022).

4.3 Risk of Misuse and Ethical Problems Beyond Medicine

Gene editing and xenotransplantation can also be used for the wrong reasons. Some people worry that these tools could be used not only to treat diseases, but also to make people stronger or smarter. This raises the big question of whether humans should use this technology to alter nature (Loike and Kadish, 2016; Goerlich et al., 2019). If people start using this technology for things other than medicine, they may face unexpected new problems.

In addition, the use of animals for organ harvesting raises animal welfare issues. Researchers need to consider how the animals lived and whether they suffered in the process. It is important to treat animals as humanely as possible and avoid unnecessary harm. Laws and rules should be in place to prevent abuse and ensure that they are used in a fair and ethical manner (Johnson, 2022; Goerlich et al., 2019).

5 Religious and Cultural Controversies

5.1 Different religious views on gene editing and xenotransplantation

Different religions have different views on gene editing and xenotransplantation. In Judaism, saving a life is seen as the most important thing. So even if the organs come from animals that are not kosher, like pigs, using them is usually allowed if it can save someone. They believe saving a life is more important than food rules, so this kind of medical treatment is acceptable (Sharifova et al., 2022).

Christianity has a similar view. Many Christians think xenotransplantation is good if it helps people heal or survive. It follows the idea of love and care taught by Jesus. They care about the person’s health as a whole—body, mind, and spirit (Sharifova et al., 2022).

Islam has a more complex view. Life is important in Islam too, but using pig organs is a big issue because of religious food laws. Still, some Islamic scholars believe it can be allowed if there are no other choices and it can save a life (Sharifova et al., 2022).

Hinduism and Buddhism also bring special concerns. In Hinduism, people believe all life is sacred, so using cow organs might be a problem, similar to how pigs are seen in other religions. In Buddhism, people believe in rebirth, so some may worry that using animal organs could affect the next life of either the person or the animal.

5.2 How culture affects acceptance of gene-edited animal organs

Cultural values also play a big role in whether people accept animal organ transplants. In Western countries, people usually support science and medical progress. Many believe xenotransplantation can help solve the shortage of human organs. The middle class, in particular, may see this as a smart and necessary way to save lives. But not everyone agrees. Some people are still unsure because of how they view animals or because they don’t trust genetic technologies.

In Eastern cultures, like in China and Japan, people may be more careful or even resistant. For example, some believe taking organs from brain-dead people is already disrespectful. So they may feel uncomfortable about using animal organs too. Also, traditional beliefs about keeping the human body whole and natural make it harder to accept such treatments. These cultural views should be respected when planning how to introduce these new medical technologies.

5.3 Including cultural and religious views in global rules

When making global rules for gene-edited animal organ transplants, we need to think about different religious and cultural beliefs. Groups like the World Health Organization (WHO) suggest countries build rules that follow strong ethics while also respecting local traditions (Goerlich et al., 2019). This helps balance medical progress with people's values and concerns.

To do this well, it’s helpful to talk with religious leaders, ethicists, and local communities. Listening to them can help make better guidelines that people are more likely to accept. For example, being open about where the organs come from and what changes were made can make people feel safer. Also, teaching people about how xenotransplantation works and what it can do may reduce fear and increase public support (Rollin, 2020).

6 Regulatory Frameworks and Challenges in Different Countries

6.1 Policies on gene editing in the U.S., EU, and China

In the United States, gene editing is mainly regulated by the Food and Drug Administration (FDA). This includes things like using gene-edited animal organs for transplants. The FDA has strict rules. New products must go through animal tests and clinical trials before they can be used on people. This is to make sure they are safe and work well. The idea is to support new science while still protecting people and the environment (Thom et al., 2023).

In the European Union, the system is more complicated. Besides EU-wide rules, each country also has its own laws. The EU is more careful about gene editing. They often focus on ethics and possible risks. Their rules are made to protect people’s health and values, but they still leave some space for research and development (Custers, 2017; Mahalatchimy et al., 2021).

In China, the rules have gotten more attention after the gene-edited babies case. Right now, gene editing of human embryos for clinical use is not allowed. This matches the global view that such work is too risky and raises serious ethical issues. But some experts say that enforcement of these rules is still not strong enough. So people are calling for better oversight (Li et al., 2019).

6.2 Problems with current rules

Even though many countries have rules in place, there are still some problems. One big issue is that different countries have different rules. This makes it hard to work together across borders. For example, the FDA in the U.S. has clear guidelines, but in the EU, different countries may slow things down because their rules are not always the same (Mahalatchimy et al., 2021; Thom et al., 2023).

Another problem is that current rules don’t always cover ethical and social questions. Technologies like CRISPR-Cas9 are developing very fast, but laws and policies haven’t kept up. This can lead to gaps in regulation and create moral problems—like the risk of misuse or unexpected side effects. Also, many rules focus only on safety and effectiveness. They don’t always think about things like animal welfare or how these changes affect nature and society (Kritikos, 2018; Nordberg et al., 2020).

6.3 Why global cooperation and standards are needed

Gene-edited animal organ transplants involve complex and sensitive issues. That’s why countries need to work together and create shared standards. With international cooperation, countries can learn from each other, make their rules more similar, and handle ethical concerns better. This matters a lot because science is global, and gene editing can have effects beyond one country (Nordberg et al., 2020; Thom et al., 2023).

Having international rules can also help the public trust this kind of research. If the process is open and includes voices from scientists, ethicists, leaders, and the general public, the discussion becomes more fair and balanced. Clear standards can guide safe and responsible innovation. This way, we can get the benefits of gene editing while reducing risks and ethical concerns (Kritikos, 2018; Mahalatchimy et al., 2021).

7 Safety and Regulatory Issues in Clinical Trials

7.1 Safety risks of animal organ transplants, especially virus transmission between species

Using animal organs in humans, also called xenotransplantation, has some serious safety risks. One big worry is that viruses from animals, like pigs, might spread to people. For example, pig organs carry something called porcine endogenous retroviruses (PERVs). These viruses could infect humans and create new diseases (Fung and Kerridge, 2016). Because of this, scientists need to be very careful. Before any trials, they must check the animals and their organs to make sure they are free of dangerous viruses (Jorqui-Azofra, 2020).

Another problem is that the human body might reject animal organs. This immune reaction can cause big health problems. Gene editing tools like CRISPR/Cas9 are helping with this. They can make animal organs less likely to be rejected by the human immune system. But even with these new tools, we still don’t know if the organs are safe in the long run. Clinical trials are needed to test that (Fung and Kerridge, 2016; Jorqui-Azofra, 2020).

7.2 Clinical trial progress and ethics review

Xenotransplantation has come a long way in recent years, especially with gene editing. Some trials using pig islet cells have shown good results. Now, experts think that using whole pig organs in trials could happen soon. Some countries are updating their rules to allow this kind of research, but global rules are still not fully in place. It’s important to create shared guidelines so that trials are both safe and ethical (Jorqui-Azofra, 2020).

Because this kind of work is risky, the rules for ethics review are very strict. Ethics committees must check things like the risks and benefits, how patients are chosen, and how the trial is planned. There also need to be good systems in place to watch over the trial and make sure researchers follow the rules (De Jongh et al., 2022). It's also important to talk openly with the public and include them in the conversation. This helps people trust the research and feel more comfortable with the technology (Jorqui-Azofra, 2020; Li and Wang, 2024).

7.3 The challenge of informed consent in gene-edited organ transplants

Getting informed consent for gene-edited organ transplants is not easy. This is a new and still experimental technology, so patients need to know exactly what they are agreeing to. They should be told about all the possible risks and benefits, including long-term effects that we might not fully understand yet. They also need to understand the ethical issues with using gene-edited animal organs. The case of the gene-edited babies in China showed how serious things can get when proper consent is not given (Li et al., 2019).

Doctors and researchers need to explain things clearly. Patients should know that this is still an experimental procedure and that some problems might not show up right away. Ethics committees must make sure that patients are not pressured and that they really understand what they are agreeing to. This is even more important in early-stage trials, where the risks are higher and not fully known  (De Jongh et al., 2022).

8 Importance of Public Engagement and Education

8.1 Helping the public understand and accept gene-edited organ transplants

If we want gene-edited organ transplants to work in real life, the public needs to understand and accept the idea. People have been interested in using animal organs for a long time—since the 1800s. Back then, doctors already thought about using animal organs to fix the shortage of human ones (Loike and Kadish, 2018).

But even though medical science has come a long way, many issues are still there. People worry about ethics, health risks, culture, and cost. These problems need to be talked about before most people can truly accept this kind of transplant (Loike and Kadish, 2018).

Using gene editing in animals to grow organs for people also brings up a lot of ethical questions. Studies show that many people are unsure about this. That’s why scientists, the public, and experts in other fields need to talk more with each other. These conversations help science move forward in a way that matches people’s values and expectations (De Graeff et al., 2018).

8.2 Why being open with information builds public trust

If the public wants to trust gene-edited organ transplants, it must be honest and clear. When scientists hide information or skip ethical rules - as happened with the first gene-edited babies - there is a loss of public trust (Li et al., 2019).

It is important for scientists, government officials and the public to discuss it openly. Everyone should know what's going on, what the rules are, and what issues still need to be addressed. For example, a conference was held in the United Kingdom. Bring experts together to discuss the major challenges facing xenotransplantation. They all agree that being transparent helps a lot (Thom et al., 2023). When information is shared clearly and honestly, and when rules are strictly followed, people feel safer, making the public more open to the use of gene-edited organs.

8.3 How does education help people understand and accept science

It is important to educate patients and the public about gene-edited organ transplants. The topic is complex, and it raises ethical and legal questions. If people understand science better, they can participate in conversations and give more thoughtful opinions (Palazzani, 2023).

Educating patients about how gene editing works can help reduce fear and build support. One idea that could help is called "One Health," which tells the story of how human and animal health are linked. This idea can help people see the bigger picture and understand the ethics behind science (Capps, 2019). Integrating ethics into education and policy, building a society that knows more about the topic of transplantation and feels more confident talking about it, and making the challenges posed by gene-edited organ transplants easier to solve.

9 Future Outlook

9.1 What might happen next with gene editing in animal-to-human transplants

Gene editing in animal-to-human organ transplants looks promising in the future. One big reason is the CRISPR/Cas9 technology, which makes it possible to change genes quickly and precisely. Scientists are using it to create pig organs that are safer for humans. For example, removing parts of pig DNA that may carry viruses and making organs less likely to be rejected by the human immune system (Fung and Kerridge, 2016; Eisenson et al., 2022; Li and He, 2024), which could solve the big problem of not having enough human organs for transplantation.

Researchers are still working on the hope that animal organs will work better in the human body, and that animal organs will live longer and function more like human organs (Loike and Kadish, 2018; Zeng, 2023). As science continues to advance, some animal parts may one day be widely used in hospitals. Today, different countries have different rules for xenotransplantation. This makes things confusing and sometimes slows down progress. Many experts think it’s time to make some shared global rules. These rules should make sure the organs are tested properly and that the whole process is safe (Goerlich et al., 2019; Jorqui-Azofra, 2020). Good rules would include clear steps for testing, managing risks, and checking if the work is ethical.

Besides the rules, we also need strong global ethics standards. These should protect both people and animals. For example, we need to care about animal welfare, watch out for diseases that could jump to humans, and keep track of patients after surgery for a long time (Johnson, 2022; Thom et al., 2023). With clear and fair ethical rules, scientists can move forward in a way that respects life and earns public support.

9.2 Better rules and global ethical standards

Today, different countries have different regulations for xenotransplantation. This throws the whole order into disarray and sometimes slows progress. Many experts argue for common global rules. These rules should ensure that organs are properly tested and that the procedure is safe (Goerlich et al., 2019; Jorqui-Azofra, 2020). Good rules should include clear steps for testing, risk management, and checking that work is ethical.

In addition to national rules, there needs to be global ethical standards. Protect people and animals, care about animal welfare, be alert for diseases that may be transmitted to humans, and follow up with patients long after surgery (Johnson, 2022; Thom et al., 2023). With clear and fair ethical rules, scientists can move forward in a way that respects life and earns public support.

9.3 Balance ethics, public opinion and scientific progress

For xenotransplantation to work in the real world, ethics and public support are as important as science. People need to understand what's going on and be comfortable with it. That's why it's so important to talk to the public and educate them. People are more likely to support research if they know the facts and feel heard (Jasanoff, 2018; Cozzi et al., 2021).

Scientists must adhere to strict ethical guidelines on the need to treat animals humanely, protect patients, and ensure that there is no danger to public health (Jorqui-Azofra, 2020; Johnson, 2022). When researchers do things the right way, they make major breakthroughs while remaining responsible and respectful. Only then can the transplantation field develop in a safe and reliable way. When researchers do things the right way, they make major breakthroughs while remaining responsible and respectful. Only then can the transplantation field evolve in a safe and reliable way.

10 Concluding Remarks

Using gene-edited animal organs for human transplants, also known as xenotransplantation, brings many ethical and legal questions. People worry about whether it’s right to use animals to help humans. Some say the act itself is wrong, no matter the result. Others focus on what happens after—like whether it helps or harms people or animals. These two kinds of views often guide the debate.

A big concern is that the human body may reject animal organs. Another is that the animal's own viruses, such as those in pigs, can be transmitted to humans. Because of these risks, we need strong safety rules and clear guidelines before these transplants can take place. The technology could also change medicine in a big way, solving the huge problem of not having enough human organs for people who need transplants. Gene-editing tools like CRISPR/Cas9 can help make animal organs safer and reduce the chance of rejection or disease.

But we can’t ignore the ethics. Using animals like this makes people ask tough questions about animal rights. If we one day grow human organs in animals, it might also raise new moral problems. We need to think carefully about what’s right and wrong before moving too fast.

To make progress in a responsible way, we need more research. Scientists still need to test if these transplants are safe and actually work well, especially over the long term. At the same time, we need better ethical rules—ones that talk about animal care, genetic editing, and other new challenges. The laws also need to catch up with the science. Clinical trials should follow updated rules that protect both people and animals. And most importantly, people from different fields—scientists, ethics experts, lawmakers, and the public—should keep talking to each other. Only by working together can we make sure this new field grows in a safe, fair, and thoughtful way.

Acknowledgments

I would like to express my gratitude to my colleagues and research partners for their support and assistance in literature review and data analysis.

Conflict of Interest Disclosure

The author affirms that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

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