The University of Southampton

Engineering Replacement body parts 2023-2024

An interdisciplinary module

Should Adults Qualify for Bilateral Cochlear Implants?

NICE guidelines state that ‘simultaneous bilateral cochlear implantation is recommended as an option for […]: children; adults who are blind or who have other disabilities’. Unilateral cochlear implantation is recommended for those with severe to profound deafness but bilateral cochlear implantation is not recommended on a cost-effectiveness basis. With the improvements shown below for adults after receiving a second implant, why does the NHS only cover unilateral implantation?

For Bilateral Cochlear ImplantsAgainst Bilateral Cochlear Implants
Improved speech perception in noisy situationsPossible worsening of tinnitus as a side effect
Improved directional perception of soundNot considered cost-effective
Easier, less exhausting conversation
Table demonstrating reasons from the NICE guidelines for and against bilateral cochlear implantation for adults. The data came from a small sample of studies.

When making decisions for the guidance ‘the committee did not consider […] different cochlear implant systems were associated with different cost-effectiveness profiles’. The main focus of the guidelines was to find the cheapest option to restore hearing, and this is repeated throughout the document. The guidelines were made in 2009. A 2018 update included a 15% reduction in costs that were not adjusted for in cost-effectiveness profiles, and a lack of update as to current models on the market.

It was found that for a simultaneous bilateral implant in an adult to be cost-effective, the NHS would require a 75% discount on the second implant. Although simultaneous bilateral implantation has better results than sequential bilateral implantation, adult patients who wish to have bilateral implants are forced into sequential implantation as they must fund the second implant themselves.

It is time these guidelines are reassessed using a larger sample size and a greater focus on patient wellbeing and quality of life. If data still shows that bilateral implantation is not cost-effective, could the NHS look to cover some of the second implant cost?

Deaf adults should receive the same level of care as deaf children. The data used is identical for children and adults, but the NICE committee came to the conclusion that children are more cost-effective and will have a greater improvement in quality of life after receiving bilateral implants. Expecting deaf adults to pay upwards of £20,000 for their healthcare when other, more expensive surgeries are covered does not sit right with me. This leaves deaf adults unnecessarily struggling day to day which is unfortunate given people with hearing loss are twice as likely to experience mental health difficulties.

Making the only route to restoring hearing to the level science can an expensive one is unfair to put on someone who is likely to be struggling to work. This is particularly prominent for those with sudden deafness (i.e. from illness or injury) or those whose hearing has declined rapidly, preventing them from having time to save money. Many people end up fundraising for their second implant, but restoring hearing should not be a luxury few can afford – particularly given that the individual cost of an expensive implant is not far below that of a pair of cheaper implants.

DermaGro: It has to Derma-Go!

Look younger, look natural, look flawless. In modern society, the pressure to reach an ever-more-unattainable level of youth and beauty as one ages is constant. There is a nonstop barrage of anti-ageing creams and pills advertised on TV and treatments and therapies available by estheticians and plastic surgeons. It all sends a clear message: ageing is offensive and ugly, and something to be prevented by all means possible, not embraced. 

Another treatment joining the legion of other anti-ageing therapies is DermaGro—a ‘miracle’ stem cell technology that has been claimed to treat wounds and burns, relieve eczema, and reverse the visible signs of ageing. Unless you’ve been living under a rock, you’ve likely encountered the buzz around DermaGro. Its aggressive social media marketing and the heated debates about its efficacy and ethics have been hard to miss. Here’s a quick rundown on how DermaGro is purported to work: 

Images from DermaGro’s website.

You sign up for their services online (and pay a hefty fee for the privilege), and soon after go to one of their clinics to have stem cell samples taken for culture. Once these are screened, selected, converted to selectively mutated and cultured, they are sent to you along with your starter kit (for yet another fee), followed by repeating deliveries of stem cells as and when you need them on a subscription basis (which if you haven’t guessed yet, comes with more fees and hidden charges!). You then keep your stem cells in the freezer until you need to apply them, which is done by loading them into the ‘gun’ and applying them to the wound. Easy enough right? They’re your own stem cells in your own home; how can there be any issues?

But there are issues aplenty… even if we ignore the ridiculous fees (you’re coming up to £3000 for just a month of treatment), there are still logistical issues. It is well known throughout stem cell research and bioscience in general that stem cells must be cryogenically preserved at -80 to below -150 degrees Celsius for them to be properly preserved and remain viable. However, DermaGro claims it is perfectly fine to store samples in a regular household freezer which only reaches temperatures of about -18 degrees Celcius, far too high for proper storage of stem cells.

Additionally, DermaGro claims to offer a ‘donor service’ where another person’s allogenic stem cells are used as a replacement for the customer whose stem cells cannot be used. However, no one fully knows where these stem cells come from. Not even DermaGro’s CEO will answer the question when asked (I directly contacted DermaGro, the CEO’s personal email and asked via their Instagram stories to no avail). Although DermaGro implies otherwise, some people have theorised that they are excess cells taken non-consensually from other patient’s samples. This raises massive ethical issues as patients do not consent to their cells being used for other people’s treatments when they sign up, and they receive no compensation for assisting other people’s treatments. Another more theatrical theory is that, much like the Hwang affair, researchers within DermaGro labs and clinicians within their donation centres are being pressured to donate their tissue to increase the supply of allogeneic stem cells, although the proof for this is still yet to come to the surface.

Although rather lengthy, this video and its sequel give a good explanation of the Hwang scandal and, thus, the implications of the DermaGro allegations.

Finally, and most damningly, there have been reports that some early DermaGro trial patients were given a cocktail of drugs to support their treatments, and upon the initial signs of the stem cells being rejected, immunosuppressants were added to the mix. This is absolutely absurd. It displays a deeply horrifying and frightening lack of medical duty and basic ethics by DermaGro. In what world is looking younger or healing a wound faster worth risking cancer? Ultimately, DermaGro is a scam—an expensive, immoral and dangerous scam at that and one which targets the superficial insecurities of ageing women. I certainly won’t let these predatory frauds ‘get under [my] skin’, but I hope this article will get under theirs. We’re now left with only one question: How long until someone dies from DermaGro?

Please note that this blog post is not for marking, and rather is a part of the group project assignment.

Unpacking the Nuremberg Code’s Legacy in Medical Research

Since 1947, a set of ten standards has existed to prevent harm to human subjects during clinical trials, following the infamous Nazi human experiments that took place during World War II in concentration camps. These horrific trials left many dead, and almost all survivors experienced permanent severe injuries. The crimes included transplantation, amputation, starvation, freezing and sterilization amongst others, and any victims who stood against the doctors were sent to the gas chambers. As much as it can be unanimously agreed that this is one of the greatest examples of brutal medical malpractice, it can be surprisingly difficult to unpack the ethics of using the collected knowledge in the 21st century for the advancement of modern health.

Jadwiga Dzido showing her scars from medical experiments

There are two major arguments against using the data obtained from the experiments. Over the years, the data has been used in multiple fields. I would like to focus on the Dachau freezing experiments, which are possibly the most controversial due to their prevalence in 20th-century research publications into the treatment of hypothermia. This involved ‘participants’ being submerged in tanks of ice water, some anesthetised, others conscious, to induce hypothermia, so that rewarming techniques could be tested on their efficacy and bodily responses. I use the term ‘participants’ extremely loosely, since this was done without consent, usually forced or under the false pretence of release from concentration camps.

Argument one considers the actual value of the data collected regardless of its ethics. Physician-scientist Andrew Ivy declared ‘Nazi experiments on humans were of no medical value’ at the Nuremberg war crime trials. However, recently, several investigators have suggested the Dachau study did produce credible data. Understandably, there is no ethical way to generate the data produced from this study, and important understandings on treating hypothermia could be life-saving. This is where argument two gains significance. The data gathered could potentially be considered ethically usable if it is for the greater good.

The experiment should be such as to yield fruitful results for the good of society, unprocurable by other methods or means of study, and not random and unnecessary in nature

– The Nuremberg Code

Conclusion

Now, the Dachau experiments completely go against all but one of the ten postulates of the Nuremberg Code. There was no informed voluntary consent, injury and suffering was certainly not avoided and there was absolutely no opportunity for the human subjects to terminate the trials. In every sense of the word, these experiments were not ethical. Whether they should have occurred is not up for debate. But since replication of these experiments is off the table, and lives could be saved with this knowledge, could it be suggested that the saving of lives is almost … honouring those who died and suffered? Equally, however, it could be argued that continuing to revoke their ability to consent is entirely dishonourable. In my opinion – in an ideal world, these experiments would never have happened. The 15,754 documented victims died needlessly. Despite this, if it can be agreed that the data collected is of scientific relevance and value, could be used for the greater good, and cannot be ethically replicated, this data should not go to waste, along with the legacy of the victims.

Would you trust a computer with your life?

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.

https://www.organdonor.gov/learn/organ-donation-statistics

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?  

Sarah Meredith (left) with her mother Catherine (right)

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.

Are cochlear implants a sound decision?

The external bionic ear captures sound waves and converts them into digital signals. An internal receiver-stimulator implant receives these signals and converts them into electrical energy. The electrodes stimulate the auditory nerve, bypassing damaged hair cells, for the user to perceive the signals as sound.

Following the cochlear implant workshop and ethics lecture, I felt inclined to reflect on the perspective of a cochlear implant user. While there are 12 million deaf people in the UK, this figure is set to increase, and there are still not many strategies to accommodate for non-hearers. The only emerging help I have witnessed are the use transcripts at the cinema, conferences or for some university lectures and also offering adjustments on work applications. I am interested in this area primarily due to unfamiliarity, I was uneducated on this area before attending the cochlear implant lecture and workshop within this module.

Furthermore, the cochlear implant is an outstanding technology, but it has its disadvantages such as reimplantation and inability for some users to perceive musical frequencies. Instead of promoting the invasive procedure, I believe that society should make implement compulsory practices like learning sign language in school to slowly accommodate for a growing community. This led me to the question ‘Are cochlear implants a sound decision?‘.

A utilitarianist would encourage non-hearers to undergo this invasive procedure to benefit the ‘greater good’, being the vast number of people that do not have impaired hearing; one person undergoing a procedure is easier than educating millions. To develop my understanding on user experience, I decided to send 8 questions to someone I know has undergone cochlear implant surgery. The questions and answers provided by Participant A are attached below.

After receiving feedback on Participant A’s experience, my perspective on this area has changed in a number of ways. I definitely agree that there needs to be more education about the implants, how they work etc. The answers provided also educated me of the fact that every user’s experience is different. I was surprised to discover the opinions surrounding cochlear implants are not generalised – Participant A stated it has helped a lot in day-to-day life while surprisingly some members in the deaf community condemn others for choosing to perceive the world audibly. Another relevant point to address is the taboo surrounding ‘deaf voices’. This unfamiliarity led me of this TikTok video uploaded by Tasha Ghouri, titled ‘Embracing my death accent‘. She recorded the entire video with her processor disconnected and made comments like ’embrace your uniqueness and show up as the person you are, no one else is you’. It is therefore important to be educated on the reality of non-hearers and encourage inclusivity.

Conclusive reflection

I really appreciated the input from Participant A and the answers encouraged me to reflect more on strategies to relieve the social drawbacks deaf people may experience. If it were in the to position I would encourage the following to meet the demands of those with impaired hearing: (1) subtitles or transcripts used for all forms of content, during live speeches etc., (2) sign language translator app, (3) patient experience talks in primary education to develop a surface-level understanding on many peoples’ reality.

American sign language (ASL) for peace

To conclude, this relates to sonder and relativism, human reality is personalised and based on each person’s life experience and perspectives. Because of this it is important to be educated and offer small efforts where we can to make life easier for everyone. Most importantly, I would say that cochlear implants are a sound decision for better quality of life. The emerging technologies help bridge the disconnect between some deaf people and the ‘hearing world’ by enabling easier communication.

References

RNID. (2023). Prevalence of deafness and hearing loss. [online] Available at: https://rnid.org.uk/get-involved/research-and-policy/facts-and-figures/prevalence-of-deafness-and-hearing-loss/.

Ärzteblatt, D.Ä.G., Redaktion Deutsches (2018). Cochlea-Implantat: HNO-Ärzte stellen Weißbuch und Register vor. [online] Deutsches Ärzteblatt. Available at: https://www.aerzteblatt.de/archiv/198928/Cochlea-Implantat-HNO-Aerzte-stellen-Weissbuch-und-Register-vor.

“”Peace” in ASL colourful” Canvas Print for Sale by procrastimake | Redbubble

Gene-ius or Gene-ocide? Balancing Style and Ethics in the Age of Designer Babies

Genetically Modified Humans

A picture of what the Genesis Chamber looked like in the show “Krypton”. Each pod is a different embryo undergoing gestation artificially.

I’m sure we’ve all heard of Superman, right? Well, he was made in something called the Genesis Chamber on Krypton. This facility housed the fetuses of the future population of Krypton, all the genes kept all in one place to carry out artificial gestation. This made me think about how one could customise their baby using gene editing. The type of technology required to do this is no longer science fiction but a reality. Known as CRISPR/Cas9, this gene editing technology can efficiently remove and insert genes from the genome of a live organism by using the enzyme Cas9. For example, Chinese scientists have found a way to conduct genetic modification on human embryos, essentially creating GM humans!

The 4 Views of Ethics

Without realising things like this are currently possible, it made me wonder about the moral philosophies that must have been considered in order to carry out these experiments. The virtue of a concept lies in its purpose and in this case, the use of gene editing to customise children is not necessarily being used for “good” but, if used for the purpose of improving quality of crops or eliminating hereditary diseases, it would be virtuous. The value of the concept is, however, subjective. There will be disagreements where people use their influence for their own agendas instead of backing the rights of people. Utilitarianism should also be considered when deciding whether or not to implement these advancements. Maximising goodness for the majority whilst minimising suffering is key to overcoming these moral dilemmas. Would the pros outweigh the cons?

The ethical dilemma of designer babies | Paul Knoepfler – a TEDTalk addressing how CRISPR/Cas9 to edit genes, the potential “upgrades” that can be made and inevitable consequences.

The Good and The Bad

Advantages include immunity and eradication of diseases, particularly those with genetic causes. There maybe be no need for prosthetics if all human genomes are edited to be strong, tolerant and have the potential for regeneration. Editing features such as appearance could reduce societal disparities by enabling individuals to select traits deemed desirable by prevailing standards, potentially mitigating existing inequalities but potentially introducing new ones. However, this raises concerns about the erasure of racial and minority identities. Novelists like Kazuo Ishiguro have warned that gene editing could foster a class of genetically superior individuals. As a person of colour, I can see how this, if in the wrong hands, could exacerbate discrimination, prejudice, and already existing predispositions against minorities. Moreover, homogenization of traits could impede evolutionary progress, as diversity often facilitates species survival. Limitations of the technology, including unforeseen alterations in the genome and ambiguities surrounding informed consent, further complicate its ethical implementation. Questions arise regarding the societal integration of this concept, including considerations of accessibility, potential capitalization, and resultant inequalities. Determining who gains access and addressing disparities are crucial considerations in navigating the ethical complexities of genetic editing’s societal implementation.

Conclusion

To summarise, the idea of using gene editing has good underlying justifications, for example when used for the purpose of creating more tolerant genomes and reducing disease. However, it can easily be manipulated to feed the agendas of corporate powerhouses and create larger inequalities across society, reducing diversity and what it means to be human. I went into this thinking it was very cool concept but was far too futuristic to even be considered. Having found out that scientists have already modified human embryos alarmed me so what I thought would revolutionise the world to make it better for generations to come, in hindsight, may not be as glamorous as I thought.

“Mechanical” approach for prosthetics limbs.

The idea of prosthetic limbs has always fascinated me. Hi-tech robotic arms and legs can always be seen in fictional media. Due to our current advancement in technologies, we have started to see many of these fictional prosthetics become a reality. We now have sensors that can detect signals from muscle movement or the nervous system. We have motors that can produce enough torque for most daily use while also being small enough to fit on a human body. We have mind-controlled robotics arms now.

video example of mind controlled arm prosthetic

Some problems I have noticed from seeing these bionic prosthetics are that 1. while these prosthetics can be controlled just by thinking, they are somewhat slow and unresponsive. 2. since these prosthetics use delicate sensors and motors while replacing the arms and legs which are usually used for physically taxing tasks, they might require frequent maintenance.

And while I believe that if we continue to develop these technologies further, eventually we will be able to create prosthetics that have the same, even exceed the functionality of human arms, we need an alternative approach to prosthetic limbs before we get to that point.

What do I mean by “mechanical approach”

Mechanical prosthetics are prosthetics that function by using the patient’s movement. For example, these old prosthetic hands shown in the picture below.

This prosthetic hand has wires that connect the claw “hand” to the elbow of the patient which allows the claw to open and close by using the bending movement of the elbow. This prosthetic, while old and somewhat inhuman looking, allows the patient to regain some functionality of their hand with the added sturdiness of the metal claw. This is a great example of what I believe to be the main advantage of this type of prosthetics. There are also some other modern examples of inventors using this “mechanical” approach to create highly functional prosthetics without the need for sensors or motors.

Ian Davis showing one of his progress on his prosthetic hand

Ian Davis, a mechanical engineer and the biggest inspiration for me writing this blog post, was able to design and build his own mechanical partial hand prosthetics, which use the movement of his wrist to not only open and close but also spread as well. He has now improved it to include multiple finger settings, for example closing his hand while keeping the index finger extended.

An interview with David Aguilar showing his Lego prosthetics arm

Another inventor I would like to talk about is David Aguilar. He was able to create his own arm prosthetic using Legos! His prosthetic is really similar to the old claw hand in the picture above, but he has built multiple arms with slight variations that allow for different uses. Some of them even have simple motors which allow them to have more force and handle heavier loads.

My opinion

The apparent downside of this “mechanical” approach is that the patients must still have some function in their limbs to be able to use these prosthetics. Ian Davis still has his palm and thumb and David Aguilar still has functionality in his elbow. Even then, I still believe that it still has potential uses worth exploring.

Learning From My Nan – Hip Replacements


In 1992, my nan received a “simultaneous bilateral total hip replacement”, meaning both hips were replaced during the same surgery. The surgeon had only performed this type of surgery once before her, as this was a newer type of surgery in the UK. She’s had a total of 4 hip replacements, 2 on each hip, all of which were metal-on-polyethylene implants. Unfortunately, she’s suffered from numerous complications both in and out of surgery.


First of all, both hips were cemented in. I wasn’t sure why this decision was made, so I was encouraged to investigate the pros and cons of cemented hips, which I’ve summarised into the table below [1].

Cement ProCement ConCementless ProCementless Con
Cement holds the implant to the bone

Faster Recovery
 
Hardens fast
 
Mouldable material so well fixated
 
Good for those with bone strength issues (osteoarthritis)
Can crack
 
Some people are allergic, which you would only discover after getting the implant
 
If allergies exist, the implant must be completely removed and redone, extending recovery time
Bone grows into the implant
 
Stronger connection
 
No concern over cement in the body
 
Lasts longer than cemented on average


Long recovery as bone needs time to grow into the implant
 
Longer and more difficult rehabilitation






My nan was in her 50s at the time of the operation. A cementless implant would be a favourable choice for someone her age, especially considering cementing hips in makes replacing them later more difficult. However, the reason she was having her hips replaced was due to having level 4 osteoarthritis in her hips, so her bones may not have been strong enough for a cementless replacement. Unfortunately, her left hip had dislocated 3 months after the operation. This meant more bone had to be removed to replace the dislocated hip.


Image showing pulmonary embolism in the lung, labelled as “blockage” (Image modified from [2])

After the operation, they insisted she stay in the hospital for a few days. This saved her life, she proceeded to suffer from a pulmonary embolism (see image to left). This is when a blood clot blocks a blood vessel in your lungs and can be fatal if not treated quickly. They proceeded to find numerous clots throughout her body as a complication of the surgery.


Simultaneous hip replacements have a higher risk of blood clots compared to staged replacements due to the increased time on the operating table [3]. The increased risk of complications means this surgery is typically saved for younger patients in good health. However, simultaneous hip replacements have their advantages, as you only need to enter the operating room once. This means only one dose of anaesthesia, shorter overall recovery time and is less expensive than staged operations [4].


Diagram showing standard polyethylene (left) and cross-linked polyethylene (right) (Modified from [6])

Implants have seen drastic improvement since my nan’s surgery, especially for polyethylene. While 3-4mm of polyethylene is still used, the standard polyethylene wears 0.2mm annually, meaning after 15-20 years, the polyethylene would be completely worn away [5]. The new cross-linked polyethylene only wears 0.04mm annually, meaning it’d take over 75 years to wear [5]. This allows younger patients to get their hip replacements sooner without worry of needing another replacement. The cross-linked polyethylene is more robust due to the additional bonding between chains, which we can see in the diagram to the right. This allows patients to perform high-demand activities after surgery without increasing further complications. If my nan had access to cross-linked polyethylene, she might not have dislocated her new hip nor needed any further hip replacements.


My nan’s hips have once again degraded, but as she is now in her 90s, she’s too old to be operated on again. However, with materials and technology used in hip replacements rapidly advancing, we are getting closer to prosthetics that won’t need replacing. The next generation will have access to safer and more efficient surgeries thanks to her and the millions of others who have undergone joint replacement surgeries.


References

[1] El_Paso_Manual_Physical_Therapy. YouTuber [Video]. 2023 21/09/2023 [accessed 25/03/2024]; Available from: https://youtu.be/OvWXltT6zoU?si=gGals_WT9svuWXON.

[2] Lear, S. Can Pulmonary Embolism Cause PH? Lung Sounds and More. 2023  [accessed 25/03/2024]; Available from: https://www.myphteam.com/resources/can-pulmonary-embolism-cause-ph-lung-sounds-and-more.

[3] Zhang, Z.-h., et al., Risk factors for venous thromboembolism of total hip arthroplasty and total knee arthroplasty: a systematic review of evidences in ten years. BMC Musculoskeletal Disorders, 2015. 16(1): p. 24.

[4] Yale Medicine, Simultaneous Bilateral Total Hip Replacement. [accessed 25/03/2024]; Available from: https://www.yalemedicine.org/conditions/simultaneous-bilateral-total-hip-replacement.

[5] Andrew_Yun_MD. YouTube [Video]. 05/11/2021 [cited 25/03/2024]; Available from: https://youtu.be/IQloOIiZvQI?si=2_R-vfoO24C85Kkk.

[6] Thomas, J., M.E. Thomas, and S. Thomas, Crosslinked Polyethylene: State-of-the-Art and New Challenges, in Crosslinkable Polyethylene: Manufacture, Properties, Recycling, and Applications, J. Thomas, S. Thomas, and Z. Ahmad, Editors. 2021, Springer Singapore: Singapore. p. 1-15.

I’ve linked further reading to key words – these will aid in understanding and provide some context. I really recommend checking out the YouTube video embedded to cross-linked polyethylene!

Stem cells: Science’s golden egg?

Every cell within our body begins as a stem cell, from immune cells to our neurons and play an integral part of human development. There are many different types of stem cell, which are divided up into 4 classes: totipotent, pluripotent, multipotent and unipotent. Totipotent stem cells are cells that can differentiate into any type of cell, but pluripotent cells can differentiate into most, but not all cell types. Multipotent stem cells are more specific than pluripotent stem cells, but can still differentiate into a few different cell types, and Unipotent stem cells can only become one type of stem cell. Pluripotent stem cells or more specifically embryonic stem cells, are most widely used in stem cell treatment.

A diagram of the cells that an embryonic stem cell can create

So how are these cells currently being clinically used?

Pluripotent stem cells are currently being used in a host of different ways, with excellent research into the treatment of neurodegenerative diseases like Parkinson’s and many others. Stem cells have also been used to 3D print heart beating cells, as well as entire tissues. These groundbreaking discoveries only begin to scratch the surface of the incredible research that is being put into stem cells.

Picture of the 3D printed beating heart cells

What does the future hold?

Although scientists are currently struggling to use stem cells for more intricate structures, like limbs, which require multiple tissue types in order to function, I believe that in the direction in which stem cell research is going and with the unbelievably rapid rate in which it is progressing, that this will eventually be possible. I also believe that the 3D printing of tissues using stem cells will eventually allow for the 3D printing of entire organs, meaning that organ transplants are no longer needed, also nullifying the extremely long waitlists some people have to endure in order to receive a transplant, or who may not even receive a transplant at all. It would also completely eradicate any immune rejection that would occur in an organ transplant. I think stem cells are truly the ‘miracle cure’ for disease, and would revolutionise clinical treatment as we know it. I am extremely excited to see how this research develops and how much we can achieve. Stem cells really are science’s golden egg.

Are stem cells worth it?

Currently, there is a lot of debate about the ethics behind the use of stem cell therapy, specifically using embryos to harvest them. This has sparked an extremely polarising debate about when embryos are considered morally human, as since some people believe that, from the moment of fertilisation, the embryo is morally human and that destroying the embryo in order to retrieve these stem cells is murder. This very much shows a Kantian view of ethics, in which he describes ethics as what is right and questions the morality of the action. However, Jeremy Bentham’s view of ethics which is that what is good is what has good outcomes, which brings into question whether the action of destroying embryos outweighs the outcome of the production of revolutionary treatments and medical care. I believe that, as the moral status of embryos is still being debated, I don’t think that the progress which is currently being made in stem cell therapy should be halted. However, I do believe that strict regulations in to how long an embryo can be grown should be put into place to minimise exploitation and unethical behaviour by allowing for the embryo to begin developing much further.

Strides Towards Comfort: Enhancing Canine Lives Through Prosthetic Innovation

Observe Nuchal, a canine under the attentive care of Bishop Ranch Veterinary Center, confidently navigating life with three legs.

When considering prosthetics, our minds often gravitate towards their application in human medicine. Yet, what about our beloved canine companions? Yes, dogs receive prosthetic limbs too! Although dogs with an amputation can continue to lead fulfilling lives, relying solely on their remaining limbs over time can lead to problems such as Osteoarthritis. This is where canine prosthetics come into play, offering a solution to enhance their mobility and overall well-being.

Canine amputation

A podcast episode about where canine physiotherapist Julie discusses her experience in doing physical therapy with dogs after they have an amputation.

The most common causes for canine amputations include: Neoplasia, severe trauma, ischemic necrosis, and in most cases osteosarcoma which affects over ten-thousand dogs each year in the United States, and the amputation of limbs is widely accepted as the preferred treatment in canines.

Necrosis of the paw requiring amputation.

Where amputation becomes the only viable option to preserve the animal’s life, prosthetics offer a crucial alternative to euthanasia. Beyond just saving the life of the dog, prosthetics also serve to prevent additional deterioration of existing joints, boost exercise and activity levels and enable an improved execution of daily life activities.

Canine prosthetics

Daisy the dog running with her prosthetic hind legs, showing full capability while running.

Canine prosthetics draw inspiration from human prosthetic technology. Just as with human prosthetics, crafting a limb for a dog demands meticulous attention to materials, design and alignment to ensure it meets it’s functional needs. Analyzing the way dogs walk, run, and jump allows us to create a limb that distributes weight correctly and provides adequate shock absorption, minimizing impact on the body. Similar to humans adjusting to limb prosthetics, dogs also require time to adapt, necessitating regular vet check-ups to ensure the prosthetic is well-suited and the dog is adjusting adequately.

While researching this topic I discovered that most canine limb prostheses can be classified in two types- Exo-prosthesis and Endo-exo prosthesis:

Figure obtained from: Vet World. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8654758/#ref19
Left – A canine limb exo-prosthesis consisting of four elements: socket (a), a liner (b), a suspension system (c), and a shock-absorbing pylon (d).
Right – A canine endo-exo prosthesis that involves attaching an exo-prosthesis (b) directly to the remaining bone in the amputated limb (a) via Osseointegration.

Common complications are manageable and include pressure sores which can be alleviated by providing padding near the affected area. Additionally, in cases where the dog underwent surgery to install it’s prosthesis infections can occur after surgery but are treatable with antibiotics. Although manageable, smaller dog breeds may face heightened complications. This surprised me as I did not think that dog breeds would be an individual factor that would affect the outcome. To address this, smaller breeds often opt for lighter metal, such as aluminum, for thier prosthetics to mitigate potential challenges.

For dogs with hind leg amputations, dog wheelchairs present an alternative, more economical option. These wheelchairs offer support to amputee pets, aiding in balance and relieving weight on remaining limbs. Although in my perspective, dog wheelchairs carry limitations absent in prosthetic legs, rendering them outdated. They occupy space and can potentially hinder a dog’s natural mobility. Additionally, wheelchairs necessitate supervision and aren’t engineered for extended, unsupervised use. In contrast, prosthetic legs provide a sustainable, adaptable solution to address canine mobility impediments thus I feel like this is where funding and resources should go towards.

It could be argued that the resources and funding allocated towards enhancing technology for dog prosthetics could be redirected towards advancing human prosthetic technology. However, upon careful consideration, it becomes evident that investing in canine prosthetics holds substantial value. Not only do dogs play vital roles in many people’s lives as companions and service animals, but the innovations made in veterinary medicine may potentially pave the way for advancements in human medicine as well.