Over 100,000 people in the UK are waiting for an organ transplant and every 8 minutes another person is added to the list. However, there is a huge shortage of suitable donors meaning 17 people die each day waiting for a transplant.

With so many patients waiting and so few donors, when an organ becomes available for transplant, the decision of the correct recipient can be a difficult one. To aid this decision, healthcare providers use algorithms to decide who is next on the list to receive a transplant. Should a computer be trusted with such a life-or-death decision?  

31-year-old Sarah Meredith fell victim to this algorithm whilst waiting for her liver transplant. Sarah was not made aware of the National Liver Offering Scheme (NLOS) algorithm that would be used to influence her wait time. When a liver becomes available for transplant, the algorithm calculates a transplant benefit score (TBS) for each patient based on 28 variables, mostly from the recipient – whoever has the highest TBS is offered the liver. Whilst the overall number of deaths whilst waiting for transplant has dropped since the introduction of this algorithm, younger patients are being made to wait far longer than before – Sarah waited over 2 years after being informed her wait time would be 68 days. 26 to 29 year olds are now waiting an extra 116 days due to the algorithm, suggesting it might disadvantage certain individuals.

My thoughts

The complexity of prioritising patients on waiting lists puts a heavy moral responsibility on medical professionals. Therefore, the use of an algorithm seems like a practical solution to take pressure off medical professionals and aid this difficult decision. However, in practice, a computer lacks the empathy and judgement of the human brain, so I don’t think they can be trusted to make decisions in life-or-death situations. Additionally, this algorithm overlooks reduction in life expectancy with increased transplant wait time – should we prioritise older, more vulnerable patients when doing so takes years off the lives of younger patients?

The solution?

Whilst current algorithms in use may not be 100% fair, I don’t think they should be scrapped. A new technology developed by the University of Bradford, OrQA (organ quality assessment), has been nominated for the Medipex NHS Innovation Award. OrQA uses technology similar to facial recognition to assess donor organs and match them to a recipient. AI like this, based on information from the donor rather than the recipient, provides an unbiased solution which will help healthcare providers reduce transplant waiting times. It is estimated to allow 100 more liver transplants a year; but, is this enough with over 10,000 people waiting for a liver transplant?

Are pigs the future?

Growing new organs for transplant would quickly reduce waiting times. Scientists have explored the possibility of using pigs and xenotransplantation to do this. In 2022, David Bennet received the first ever pig heart transplant. The pig heart was genetically modified before being transplanted, and Bennet was given drugs to prevent immune rejection of the pig heart. Bennet lived for 2 months with his pig heart before it failed. In the current situation, I’m sure many would agree with me when I say I would be skeptical receiving a pig organ transplant. However, with more research, breeding genetically modified pigs and harvesting their organs for xenotransplantation could revolutionise the organ transplant process and remove the need for patients to put their lives in the hands of a computer.

As my father prepares for his upcoming hip replacement surgery, I find myself reflecting on his fortunate access to private healthcare. The journey leading up to this decision has been far from straightforward. He has undergone numerous doctor’s appointments, consultations, treatments, and procedures, all aimed at providing relief from his debilitating condition. After exploring all other options, he has ultimately chosen to undergo the hip replacement surgery.

A hip replacement is a surgical procedure where a damaged or diseased hip joint is replaced with an artificial joint made of metal, ceramic, or plastic. By replacing the damaged joint with a prosthetic one, it not only relieves discomfort but also improves overall function, allowing patients to get back to their normal life, something that I am very excited for my dad to get back.

Thankfully, advancements in hip replacement technology have made way for significant improvements in recent years. Enhanced prosthetic materials, including durable ceramics and metals, now closely mimic the natural movement of the hip joint. New surgical techniques and tools such as robotics have all further contributed to these improvements. These innovations have revolutionised patient outcomes, offering swifter rehabilitation and improved quality of life.

Fortunately, my dad has access to private healthcare through his work and has therefore decided to proceed with the hip replacement privately. Although I am over the moon that my dad can get the care he needs quickly, it has got me thinking about the healthcare accessibility and disparities that exist within our healthcare system.

Not everyone has the luxury of access to private medical insurance. Patients undergoing NHS treatment for their hip replacement may endure lengthy waiting times for surgery. On the NHS website it states that the longest waiting time for a surgery should be around 18 weeks, but this is from the point of referral for the operation, and does not consider the time spent waiting to get the referral, which can be months! This can make the situation worse, diminish quality of life, and impose significant emotional and physical stress on patients and their families.

My dad’s hip replacement surgery is scheduled for next month. Reflecting on healthcare disparities leads me to question whether my dad would have been offered the option for such prompt surgery under different circumstances. I highly doubt it.

I decided to interview my dad to gather insight into his thoughts on his upcoming surgery and to understand the extent to which his hip affects his daily life. Additionally, I spoke with his colleague, Aubery Smith, who underwent a hip replacement surgery through the NHS to gain further perspective (transcript below).

While my father and Aubery Smith both have/ will have their procedures done at the same place, Aubery had to wait “approximately a year” to undergo his hip replacement surgery through the NHS. I cannot imagine enduring the pain he and my father described for such an extended period, and I strongly feel that changes should be made to address this disparity.

Overall, hip replacement surgeries have significantly advanced, offering individuals the opportunity to regain their daily lives pain-free, which is invaluable. However, I believe the healthcare system needs to implement additional measures, such as a reimbursement scheme. This would ensure that individuals in dire need of hip replacement surgery, whose quality of life is diminishing but lack access to private healthcare, can promptly receive the treatment they desperately need. Put yourself in their shoes; wouldn’t you look for timely treatment if faced with a similar situation?

As a natural sciences student, my degree is all about interdisciplinary science. I’m currently taking a third-year microbiology module, so when I found out I could write this blog on any subject related to engineering replacement body parts I was determined to find a link between my fascination with microbiology and an application to human health.

Using bacteria in biosensors

During the two lectures on sensors an ‘artificial pancreas’ was discussed, which combines a blood glucose sensor with an insulin delivering device to precisely monitor and modulate the blood glucose concentration in people with type I diabetes. This innovative technology inspired me to investigate if there could be a link between biosensors and microbiology. I quickly found an article describing bacteria biosensors. Bacterial biosensors, known as whole cell bacterial biosensors (WCBBs), work by utilising bacteria’s natural system of recognising a molecule and responding to it by producing a protein. The biosensors use genetic engineering (GE) to engineer the bacteria to recognise specific molecules and produce specific reporter proteins in response. These reporter proteins then act as a signal for the presence of the analyte which can be detected by a computer interface.

Bacterial biosensors in practice

These WCBBs are useful in a biomedical setting, allowing the detection of molecules which may be indicative of disease, such as WCBBs which can detect cancerous DNA. However, for these biosensors to work, they must have access to the body. Engineers at MIT have developed an ingestible bacterial biosensor capsule, which they hope will soon be clinically applicable, allowing the continuous monitoring of gastrointestinal health over weeks. Therefore, through the collaboration of biological and material engineering, these MIT researchers have facilitated the use of these biosensors in the body.

The debate surrounding genetic engineering

GE is often a controversial topic, with negative media coverage most commonly against genetically engineered crops. The main concern is the effect of GE species in the event of their uncontrolled release into the environment. Professor Caroline Ajo-franklin, who runs a biosciences research group at Rice University developing WCBBs, describes the need for tactics to prevent such an environmental release of GE microbes through physical containment. Overall, I believe that using proper regulation to perceive and mitigate risks, GE is a clear force for good in biomedical research. The discussion surrounding GE and the prevailing public scepticism towards it also highlighted to me the need for effective communication of research to the public, and the importance of open debate of new technologies and there applications.

The importance of seemingly unimportant links

What struck me most whilst researching this topic was the variety of bacterial use in engineering replacement body parts, with the WCBBs discussed above only a tiny snapshot of potential. I could have written about the use of bacterial biomolecules as biomedical scaffolds for human organ tissue culture, or the use of algal cells to help restore a man’s vision, or the complex role of the gut microbiome in our health. However, much like the word limit of this blog, the world of science research is limited by resource availability and funding. It’s impossible for a researcher to explore every rabbit hole, which is why I believe that interdisciplinary collaboration is integral to the future of all areas of research, and it may be the links between seemingly unrelated subjects which drive future technological breakthroughs.

Organ Transplantation

In 2022-2023 it was estimated that 4600 transplants were completed thanks to thousands of donors in the UK. However, it is also estimated that 7000 people were on the waiting list, almost 1.5x the number of transplants completed. Tragically, from this, 430 died waiting for an organ last year. This is a huge issue in modern medicine that needs to be tackled immediately. The NHS are advertising the importance of being an organ donor, in May 2022 the UK introduced an opt-out system. Each country in the UK has similar legal implications surrounding this subject; which states if you are over 18 and have not opted-out and aren’t in an excluded group, you are deemed authorised for organ donation. Scotland differs a little bit whereby you are deemed authorised at 16 and assume consent if not opted-out. This has increased the donor rate by 50% in 5 years and is hoping to double in 10.

When Death Turns Into Life…

I was first interested in this subject after reading Merzrich’s When Death Turns Into Life, which discusses dilemmas of transplant surgeons as well as their breakthroughs. Reading the trials regarding xenotransplantation pricked my interest and prompted me to research further. The efforts of Keith Reemsta, a risk-taker determined to transplant primate organs into humans was particularly fascinating. One case was that of 43-year-old Jeffery Davis, who was in heart failure and end stage renal disease and could not live on short-term dialysis. Reemsta transplanted both kidneys still connected to the vena cava and aorta and treated with the available immunosuppression medication available in 1963. Davis sadly died a month and a half later from pneumonia and not rejection. Reemsta continued transplanting a further 13 patients who enjoyed 9-60 days of extended life. I respect how driven Reemsta was to move forward his research, though in 1965 this halted when chronic dialysis became available.

Primates vs Pigs?

There is evidence now that attempting to transplant chimpanzee organs is unsustainable as they are endangered, difficult to breed, have one offspring at a time, expensive to care for and exposes humans to xenoviruses due to the homology in genetics between the species. There is also an ethical debate regarding whether these animals are too much like humans, which we would raise purely to harvest organs from, where do we draw the line?

Alternatively, pigs could be used, which have more reason to be use instead, such as easy breeding, big litters, appropriate size, fair genetic homology, cheap and more socially acceptable. This is in the sense that pigs are already harvested for pork products, why could we not harvest their organs as well to help the global shortage of organs. I think this would be a major breakthrough in research. However, using pigs could cause debates from a religious standpoint, in Islamism this would be seen as a betrayal of their religion. One of the biggest issues with using pigs is the presence of alpha-gal epitope, a protein non-primate mammals possess which could lead to rejection. Since the discovery of CRISPR/Cas9, George Church has successfully generated pigs with inactivated PERV elements, causing the threat of xenoviruses to be diminished, but is still yet to get FDA-approved.

In the book there was a lovely phrase, which I believe sums up the research in xenotransplantation perfectly:

‘Xenotransplantation is just around the corner, but it may be a very long corner’ – Sir Roy Calne 1995

Below is an interesting video about why pigs should be used for future organ donation, exploring how we may be able to genetically-modify them to prevent rejection through Chimeras.

Acknowledgements

Mezrich, Joshua D. When Death Becomes Life : Notes from a Transplant Surgeon. New York, Ny, Harper, An Imprint Of Harpercollinspublishers, 2019.

NHS. “Organ Donation and Transplantation.” NHS Blood and Transplant, 2022, www.nhsbt.nhs.uk/what-we-do/transplantation-services/organ-donation-and-transplantation/.

“Organ Donation Laws.” NHS Organ Donation, 2016, www.organdonation.nhs.uk/helping-you-to-decide/organ-donation-laws/.

“Improved System of Organ Use to Save Lives.” GOV.UK, www.gov.uk/government/news/improved-system-of-organ-use-to-save-lives#:~:text=The%20opt%2Dout%20change%20to.

Mohd Zailani, Muhammad Faiq, et al. “Human–Pig Chimeric Organ in Organ Transplantation from Islamic Bioethics Perspectives.” Asian Bioethics Review, 16 Nov. 2022, https://doi.org/10.1007/s41649-022-00233-2.

In the realm of medical science, tissue engineering stands as a beacon of hope, offering revolutionary solutions to some of the most challenging health problems. It’s a field where biology meets engineering, aiming to regenerate, repair, or replace damaged tissues and organs using a combination of cells, scaffolds, and bioactive molecules. While the potential benefits of tissue engineering are vast, it also raises significant ethical questions that demand careful consideration.

At its core, tissue engineering holds the promise of transforming healthcare by providing alternatives to traditional organ transplants, which is often limited by donor shortages, immune rejection, and the need for lifelong immunosuppression. With tissue engineering, scientists can create tissues and organs tailored to individual patients (using their own tissue), which reduces the risk of rejection and eliminates the need for donor matching.

One of the most common applications of tissue engineering is in the field of regenerative medicine. Imagine a world where patients with severe burns can have their skin regenerated using bioengineered skin substitutes, or where individuals with a damaged cartilage can receive custom-made cartilage implants! These advancements have the potential to improve countless lives, offering hope to where previously there was none.

Ethical concerns loom over the field of tissue engineering, prompting researchers and policy makers to navigate a complex ethical area. One of the primary concerns is the source of cells used in tissue engineering. While some cells can be harvested from a patient’s own body, others may come from embryonic stem cells or induced pluripotent stem cells (iPSCs), raising ethical questions about the destruction of human embryos and the manipulation of genetic material. Moreover, the commercialisation of tissue engineering raises concerns about accessibility and fairness in healthcare. Will these cutting-edge treatments be available only to the wealthy and elite, widening the gap between those who can have access and those who don’t? Ensuring equal access to tissue-engineered therapies is not just a matter of scientific advancement but also a moral imperative.

Another ethical dilemma arises from the potential for unintended consequences. As we delve deeper into the complexities of tissue engineering, we must be mindful of the long-term effects of manipulating biological systems. Could bioengineered tissues lead to unforeseen health complications down the line? These are questions that require ongoing research.

Despite these ethical challenges, the field of tissue engineering holds tremendous promise for the future of medicine. By cultivating interdisciplinary collaboration and engaging in transparent dialogue with stakeholders, we can navigate the ethical complexities while harnessing the full potential of tissue engineering to alleviate human suffering and improve quality of life.

In conclusion, tissue engineering represents a remarkable collaboration of science, engineering, and medicine, offering unprecedented opportunities to address some of the most pressing health challenges of our time. However, as we journey into this brave new world of regenerative medicine, we must tread carefully, ensuring that our scientific advancements are guided by ethical principles and a commitment to the greater good. Only then can we fully realize the transformative potential of tissue engineering while upholding the rights of all individuals.

Since the development of the Egyptian ‘Cairo toe’, prosthetic limbs have developed greatly. The Cairo toe was made from pieces of wood sculpted into the appearance of a toe and held together by leather thread. This simple model contrasts drastically to the modern-day prosthetics often constructed using metals and synthetic materials such as plastic and silicone which can provide individuals with high levels of functionality and are available with a range of different aesthetics.

Scientists are constantly trying to improve prosthetics for their recipients. Recent developments have focused on the ability to control prosthetics in the same way we would control the natural limb – with our minds. Johns Hopkins University have developed the APL bionic arm which can be controlled by the human brain. In 2016, Melissa Loomis, who lost her arm after being bitten by a wild racoon, became the first recipient of this prosthetic and one of the only amputees at the time to be able to control her prosthetic with her mind. The arm receives inputs from her nerves in her nervous system which are interpreted by the arm and result in the desired output of movement. The prosthetic also has a range of sensors across it which send signals back to her nervous system allowing her to be able to detect temperature and provide some of the senses, such as touch, to the limb. This could be life changing to amputees like Melissa who said touch was ‘the thing she missed the most’ in an interview with Motherboard.

Whilst this was a huge leap forward in prosthetic science it is not without its disadvantages. The APL bionic arm is extremely expensive, and patients need to undergo a long invasive surgery known as targeted sensory innervation to allow the prosthetic to be connected to the patients nervous system. Whilst currently these factors make the prosthetic less accessible, it still provides an exciting glimpse into the future of prosthetics for amputees.

However, for those who are unable to consider this advanced APL bionic arm, prosthetics such as the MiniTouch, recently described in nature,  may be desirable. The MiniTouch technology allows the detection of temperature through prosthetic limbs without the need for surgery. The technology works similarly with temperature sensors on the prosthetic that deliver thermal information to the patients’ neurones through points on their skin. It can be attached to many different prosthetic limbs already on the market making it much more accessible to amputees.  

Developments like these were unimaginable during the time of the Cairo toe indicating that the possibilities with prosthetics could be endless. One limb amputation happens every 30 seconds and there are over 2.1 million people living with a limb amputation in the US alone. Therefore, these advancements provide a promising glimpse into the future of prosthetic limbs with increased functionality and accessibility.

You turn up at hospital and what is the first, most basic test that they carry out? Vital observations. From the most minor injuries to surgery and intensive care, throughout the hospital at every level, vital observations are integral to medical understanding and monitoring of the individual. They can be relatively rudimentary signal acquisition systems, relaying physical signals from the patient through a signal amplifier and analog to digital converter where electrical signals can be analysed and monitored on a computer. So how has this relatively straightforward technology become so outdated in anywhere other than the operating room, when recently in Los Angeles, California, I was presented with cutting edge, holistic, remote medical sensing technology at Massimo biotechnology?

Working throughout the RD&E Exeter and SGH Southampton Hospitals, and most recently work in Coronary Care and Emergency Majors department has raised my awareness of the failures of vital monitoring systems so highly relied upon. For instance, ECG monitoring on Cardiac units currently rely upon either static or cumbersome remote ECG monitors that can be very restricting to the patient (especially those generally mobile or that become agitated without activity), require manual operation, and generally provide minimal amount of information solely related to one requirement, in comparison to the holistic, versatile, and minimally invasive remote monitoring systems currently being innovated and sold on the market.

Currently, Massimo offer the Radius VSM which provides the ‘versatility of a bedside monitor in a wearable device’. This includes pulse oximetry monitoring, respiration monitoring and rates, noninvasive blood-pressure which have customisable intervals of observation, temperature, patient mobility and orientation monitoring providing ability to detect falls and prevent pressure sores, and ECG with 6 different waveforms. The ability to monitor these variables from the nursing desk, regardless of where the patient is, can be much more time efficient and less restricting than current methods. This must also be able to factor in for artefacts that can present themselves in readings, for instance mains interference or EMG (electricity radiated from muscle) as a result of movement.

While perhaps the NHS has equipment that will “do the job”, does it work to what could be its current full potential and reflect the incredible recent advances made in bioengineering (which could lead to improved patient outcomes)? No.

The NHS has a multifaceted problem with innovation and development. This comes down to difficulty in implementing changes to a highly decentralised and overly bureaucratic system which would require a lot of coordination and investment. Investment with a tight budget from the British taxpayer and high competition between arguably just as, if not more important medical devices and materials, proves another problem. In terms of innovation, inevitably there is a reluctance within healthcare professionals to step out of the comfort zone into a new era when the old is tried, tested, and already payed for.

Despite the NHS working at a sufficient level, how far does its ethical obligation to innovate, stretch into the modern age of technology. Patient wellbeing would improve with more accurate, less restrictive systems. Equality and access to healthcare across the country with better outcomes, improved efficiency and reduced waiting times for any individual regardless of background, would also be possible. Furthermore, innovation would be an obligation of beneficence and non-maleficence with patients best interests in mind. However, to what extent this is significant in terms of resource allocation must be up for contemplation.

Evidently now the NHS has realised their need to develop in this niche with necessary trials being launched. However, the delay in this being a priority is evidence of the NHS need to improve.

Hearing loss, whether congenital or developed later in life, affects many people. 1 in 5 adults in the UK experience hearing loss, are deaf or have tinnitus. More widely, 5% of the world’s population experience disabling hearing loss. Hearing, in conjunction with the other 4 senses, aids us in our understanding and interpretation of the world around us. So you would think that anything that helps to restore hearing is a net positive, right?

Not exactly.

There is a divide in the deaf community. Some see their deafness as a medical condition, whereas others see it as a cultural identity. The former group tend to see cochlear implants as a beneficial advancement and a great option as it can potentially improve their condition. Those who fall into the latter category tend to believe that cochlear implants are inherently negative, as the promotion of them implies that deafness is something that needs to be fixed. The deaf community have their own way of communicating that has been developed over many years, and the mass adoption of cochlear implants may cause them to lose the language and culture they have developed.

Cochlear implants are beneficial, with a 2020 study in adults showing that word recognition improved from 8.3% to 53.3% after implantation. However, it requires a lot of work for the person wearing the implant to reach this point. They will have to undergo speech and language therapy, and it can take many years to adjust to. The implant also does not restore hearing in the same way that non-deaf people can hear, as some may believe.

Below is a thread from an X/Twitter user, discussing how people without hearing loss may be insensitive to the emotions and agency of deaf people surrounding their choice of whether or not to use cochlear implants. The comments are taken from a video of a child who did not want to wear her implant after her parent asks her to put it on, and requests for her parent to sign with her instead.

In the thread, the user shares screenshots of people making comments such as, “If she didn’t want it she should pay her folks back for it”, and “Everyone cannot sign. She needs to be flexible and adaptable to make it in this world”, with many comments using ableist language.

With comments and language such as this, it’s understandable why there are deaf people who advocate for children to not be allowed to have cochlear implants until they can consent to the procedure.

The comments also display misconceptions about cochlear implants. There is a rampant attitude of “If you have an implant, why should I use sign language?” The consensus is that the child is choosing to not wear her implant out of insubordination. It is common for deaf people with hearing aids or implants to want “hearing breaks”. Some people with an implant still use lipreading and sign language as they may find it easier for many reasons.

This situation highlights the main issue that some deaf people have with cochlear implants; they can be seen as an excuse for the lack of accommodations that society has for deaf people.

Overall, cochlear implants are not a miracle cure. They have the potential to help deaf people, but it is an emotionally taxing process and it is not fair to expect all deaf people to want one (or two). If someone has a cochlear implant, but doesn’t want to use it all the time, we should be empathetic to that.

A metal implant is a biomaterial commonly used in orthopaedic surgery to help bones heal, or replace them entirely. Alloys are most typically used. They are designed to be non-corrosive, hard and durable – everything needed from the implant. In the photo below, the hip replacement one is probably the most recognisable, which 71,000 people in the UK have.

https://www.sciencedirect.com/science/article/abs/pii/S1286011518302479

Deciding on the make of the implant is very important. An article I read discussed how doctors need to consider what metals the patient has already been exposed to and what metals will be problematic, however a rejection can occur without any previous hypersensitivity. It suggests management strategies in the case the implant causes immune rejection. It states “Successful medical management with oral atropine sulphate has been reported in a patient with titanium pacemaker as well as with oral corticosteroids in a patient with titanium bioprosthesis for a spinal fracture”. This highlighted the importance of figuring out what metal to use in an implant, something I had not considered in much detail. The following link describes some types of implants: https://youtu.be/FfRZuNaKGdU?si=dT2X0tKhaC6ayGcF.

Image showing examples of types of implants

Patient’s reaction to the metal implantation varies dramatically. Some people show no rejection of the metal, others can show hypersensitivity to the metal and their body actually rejects it, causing intense pain and inflammation for the individual, potentially to the point that the implant has to be removed, but then what do they do to fix the issue?

Fixing the issue, but not completely…

Something which is used to reduce the risk of implants failing is covalently immobilising biomolecules onto the metal surface. An article in the Biomedical Engineering Advances journal believes that using a covalently attached immobilised biomolecule or not is a main determinant in the efficiency of the implant. Of course, this depends on what biomolecules are used and the patient’s individual differences, everyone’s immune system will react differently to the same thing. An example of an immobilised biomolecule is fibronectin, this forms an amide bond with the metal surface, others investigate Arg-Gly-Asp-containing peptides and ubiquitin.

A downside to the use of metal implants is stress shielding. This occurs when the bone density decreases as the stress load on the bone is reduced, due to the presence of the implant. This is a major issue for implants that will not be lifelong (a lot of implants – they do not last forever). This issue may not be apparent until after the metal implant is removed, such as after a severe femur break and the leg is significantly weaker and smaller.

So, what happens when metal implants do fail?

Well, in the UK, patients who’s implants fail, or cause harm, are able to bring legal action against the manufacturers and they are held accountable. The Nuffield Council on Bioethics in June of 2019 estimates ‘over 300 UK patients whose hip implants had failed brought legal action against the manufacturer under the Consumer Protection Act 1987’.

My opinion?

I believe there are lots of ethical considerations that need to be discussed at greater length. Since metal implants have lots of uncertainty surrounding their lifetimes and consequences (as most of it has not yet been seen) it makes it difficult for patients and doctors to make the correct decision, however this does not mean informed consent is dismissed.