Contents
Human Practices - Silver
Introduction
"Human Practice is the study of how your work affects the world, and how the world affects your work." - Peter Carr
After settling on creating a product that would appropriately combine the strength of spider silk with the conductive nature of reduced graphene oxide (rGO), we began to contact representatives within both industries. Contacting graphene companies, as well as the University of Exeter's Graphene Centre, facilitated a deeper foundational knowledge of the applications, properties, and testing of graphene biocomposite materials.
Industry engagement helped us to filter our initial broad scope of applications, including clothing (Spiber), biocapacitors and space materials, to a sole focus on tissue regeneration. Once we had decided to explore the possible biomedical applications of our material, stakeholder consultation proved invaluable in determining key gaps in the market as well as the most effective way of promoting our product.
iGEM promotes the importance of creating feedback loops between our project and the world. Following this framework, we shaped our Human Practices around Reflection, Responsibility and Responsiveness.
Figure 1 - A diagram of the framework used by our team to shape our human practices work.
Reflection
Inspiration for our project stemmed predominantly from social, ethical, and industrial values. Initial research and engagement with companies such as Spiber (a biomaterials company) identified a demand for silk, particularly spidroin, in areas ranging from textiles to biomedical engineering. This growing industrial demand will simply not be met by low-yielding animal farms. Thus, the synbio element of our project - synthetically producing spider silk - is justified economically and industrially.
Although natural production of silk using spiders is limited[1], silk harvesting still relies on extraction from living spiders[2]. Given the spark in interest of spider silk for applications such as tissue engineering, there is potential for this process to become more utilised as demand for these therapies grows. Additionally, sericulture (silkworm farming) is labour intensive, presents pathogenicity risk and results in over 6,500 silkworms being killed to make just over 2 pounds of silk[3]. Therefore, we determined that the current, and possible future, widespread use of animals in silk production is ethically problematic and acted as one of the significant factors in driving us to create a synbio alternative. Additionally, synthetically produced silk is cleaner than that of silk farms, thus requiring less energy-costly stages of product purification. Synthetic biology also gives greater control over the end product of silk production. Synbio techniques take full advantage of the modular nature of MaSp proteins to tailor their properties for addressing specific applications via recombinant technologies and chemical synthesis.
Due to the exceptional potential of silk for in-vivo therapeutics, we identified the
We carried out thorough market research of current technologies in order to accurately compare our approach to alternative solutions utilised in tissue regeneration. This established the potential benefits of alternatively tackling the problem of biological rehabilitation via a synthetic biology route:
Neuroregeneration - The rapidly growing field of neural tissue engineering concerns the discovery of methods of restoring nerve functionality and facilitating recovery, post injury. Our product would act as a scaffold to guide nerve tissue regeneration in damaged areas. Many researchers are currently focussing on conductive polymers to do so, but a major drawback is that they are non-biodegradable, posing risk of long-term tissue damage or the inconvenience of multiple surgeries[5]. Our composite therefore offers a solution to fill the gaps of current therapies due to having the same desirable properties but with the bonus of biodegradability. Spider silk will degrade in vivo as shown in a study into axonal regeneration in sheep which found no traces of residual spider silk or inflammation 10 months after silk construct implantation[7]. Currently, regenerative medicine involving nerve tissue predominantly concerns the insertion of permanent structures in the body. Thus, we identified a gap in the market for a graft that will dissolve over time, providing the opportunity for the tissue to fully recover and removing the need for a permanent structure. Compared with current spidroin-based scaffolds and conduits, our design also has the added feature of integrated reduced graphene oxide to give conductivity. This enhancement helps to guide and encourage nerve regrowth to a greater extent than non-conductive materials[5]:
Figure 2 - A diagram of how a scaffold could be used to protect and direct nerve regrowth following injury.
Synthetic tendons - Adam Davies from OceanPhysio informed us that, currently, the market for strain injury treatments is dominated by ex-vivo methods including kinesiology tape and splints, in combination with physiotherapy. In contrast to external support, our internal grafts would provide mechanical support for deeper injury repair. Our scaffold could be inserted in combination with the autogenous tendon implant and external brace to increase recovery effectiveness by supporting the injury both internally and externally.
Synthetic ligaments - Regarding optimum ligament rehabilitation, invasive surgery is often required. Autografts, even those carried out using material taken from the same leg, can have issues with rejection. This concern was another factor behind our selection of material components for our biocomposite. Selecting biocompatible and non-immunogenic synthetic silk and graphene minimises the risk of issues with rejection of our implant. Therefore, using our biocompatible composite as an alternative reconstructive material could revolutionise the effectiveness of these invasive surgeries. Conferring with synthetic ligament company MovMedix, who already utilise their own technology (LARS) for clinical therapy, we were encouraged to pursue this route as one of great demand. However, our product differs as it is targeted for short-term purposes as opposed to the 20 year life span of LARS. Our composite is also derived from organic materials, rather than PET plastic.
When deciding on needs and values to prioritise in our product we often had to make compromises…
For example, MovMedix enlightened us on prioritising the needs specific to making our product industrially relevant. We also gained insight into property testing including measurements of fatigue, torsion and tensile strength, as well as descriptions of current ‘gold standards’. Background research helped us establish that the lifespan of our composite is likely to be a few months and therefore shorter-term. Thus, we honed our potential field of application from tissue regeneration into, more specifically, scaffolds for regenerative medicine in connective tissue and sports rehabilitation. Initially we had a view to apply our synthetic tendons and ligaments in various places around the body. However, Pierre Cherrelle, founder and CEO of Axiles Bionics advised that there are greater mechanical complexities of upper body extremities in comparison to lower limbs, therefore, to target our focus on the lower body would result in a higher chance of success given our limited time frame.
Naturally, our initial goals have adjusted throughout the project as we built up our stakeholder engagement as well as time in the lab…
Initial research suggested that a silk-graphene composite would boast biocompatible, conductive, elastic, and lightweight properties. This led us to initially identifying a broad potential scope of applications branching from biomedical uses to clothing, biocapacitors and space materials. Overall, engagement with industry experts enabled the streamlining of these ideas, eventually concluding that synthetic nerve scaffolds or connective tissue grafts would be the most philanthropic, realistic, and impactful route to pursue. Detailed notes about how each human practice interaction helped mould our project can be found in the AREA framework under Gold Human Practices (link to gold section here).
Responsibility
Throughout our project, we consistently made informed decisions and reflected on our own methods and aims, alongside the elements below:
Figure 3 - A word cloud of elements we had to take into account when planning our project to ensure it was responsible and safe.
Hoping to make important ethical progressions regarding animal exploitation in the silk and research industry, we are using E. coli bacteria for silk production instead of live spiders or silkworms. A positive knock on side effect of this involves safety, as it results in the reduction of potential species-jumping pathogens leading to dangerous labour conditions in large scale animal farms.
Accountability and safety have been at the forefront of our lab work to prevent any biological risks. We are using Rosetta E. coli as a chassis, and while this is a non-virulent strain of bacteria, the organisms will undergo a thorough lysing and filtration process to extract the synthetic silk from our composite product resulting in no risk of GMO contamination into our medical implants. Finally, any modifications being made to bacteria are specific to protein production and have no associated health risks to humans, in the unlikely event that contamination were to occur. We hope that honest communication between our process and the public, through avenues such as our podcast series, will help to reduce the stigma around GMOs, allowing for warmer welcoming of revolutionary synbio projects by the wider community in the future.
When assessing environmental safety and sustainability, the carbon dioxide produced by E. coli fermentation as well as the land required for the factory must be considered. Both silk farms and our synthetic sites are likely to be equal in size, but plants utilising synthetic production will have a higher silk yield with no animal element, so will be more efficient and ethical. Due to the small quantities of material required for these medical implants, production would likely be on a scale to not produce significant carbon emissions.
To ensure our values aligned with those of modern research, we consulted companies innovating in this area who educated us on the gold standards of research today. One example is Sylvia Perrone from Movmedix, who enlightened us on not only what to test for as parameters of success but also the ways in which ethical considerations can limit this process. For instance, we learned that it is difficult to ask for patient input until you are at the stage of having an implantable product, so we continued to engage with stakeholders and industry experts who could speak for the needs of our end users.
During product development we considered which communities would be most affected by our project…
We hope to appeal to global medical and therapeutic industries in order to enhance their capabilities in tissue repair, a large and potentially profitable field of medicine:
Nerves - With 90,000 people affected annually by nervous system injuries[3], we hope our scaffolds can contribute to the rapidly growing field of nerve tissue regeneration. Our current vision is designed for individuals with nervous system injuries obtained from traumatic injury events rather than genetic disease. This is because our composite has an expected shorter life span of around 3 months, so will struggle to withstand long term immune degradation. We hope to positively impact these communities by enabling deep tissue repair and speeding up recovery times via improved nerve regeneration and connectivity.
Tendons and ligaments - Our connective tissue scaffolds could be utilised in the repair of the 3-5 million tendon and ligament injury cases occurring annually worldwide[5]. Pronounced end users for both ligament and tendon rehabilitative therapies are people in the sporting industry. Mobility-limiting injuries are more likely to be operated on in young or active people. This is because the lifestyles of these demographics tend to involve stretching or pressuring their joints to a greater extent than the older population. While widely prolific within professional athletes, ligament and tendon injuries occur within the general population also, creating a broad scope for a meaningful therapeutic and economic benefit. Therefore, whilst our implementation will be targeted towards some specific demographics, we conclude that applications of our product span multiple ages and lifestyles.
We also considered which communities would be either left out or negatively affected by our project…
Naturally, due to low supply and the innovative nature of new therapies, when a biotech product first launches in the market, it will likely have a high cost. This will inevitably cause a socioeconomic divide on multiple levels as the more affluent, privatised and technologically able areas will have access to novel therapies first. To assess the effect of this, we participated in a bioprocess costing session to estimate some figures in terms of production on an industrial scale. However, even with the technology being freely and equally available, countries with more advanced healthcare capabilities will be more likely to implement this therapy successfully. This has the potential to increase disparity in quality of life and athletic opportunities (e.g. qualifying for tournaments) between higher and lower income countries. Additionally, extreme and profuse use of the technology could be used to attempt ‘superhuman’ properties such as enhanced strength.
Responsiveness
We engaged with various people who helped us to prioritise the appropriate values in the context of our project…
Since our project has the potential to regenerate tissue, therefore presenting the possibility of curing a range of disabilities, engaging with the diasbled community was essential before further progressing with our project. The transforming of societal beliefs surrounding disability from something to be ‘cured’, to something to be proud of contributes to complex discussions surrounding ‘cures’. Our drive for the inclusivity (link page) award involved interviewing PWD’s (persons with disabilities) from which we understood the severity, as well as the driving factors of the widespread mistrust of the medical industry. Many interviewees echoed the sentiment that disabilities are so ingrained in personhood that to remove them completely could result in a loss of the feeling of ‘self’. In combination with deeper understanding from engagement we have also moderated the tone of our language when marketing our product. For example, we avoid using the term ‘cure’ altogether to describe our project as this feeds into the assumption that all those with symptoms we aim to address would choose to take our treatment, which is simply not the case.
Conversations with Sylvia Perrone at MovMedix (a synthetic ligament company) helped us to really understand the depth of their company's stakeholder and client research. Particular importance was placed on engaging with end users, which drove us to engage with physiotherapists, as these are potential implementers of our product. Meeting with Adam Davies from OceanPhysio informed our ideas of what is really valued by patients in a treatment, as well as how rehabilitation plans vary depending on the age and lifestyle of patients. Learning about the needs of the demographics most likely to use our product helped to further shape our market research and frame our focus on more common and specific areas of injury.
We also engaged with several sources to determine both the feasibility and desirability of our approach…
Our main source of feedback on feasibility was from conversations with Pierre Cherrelle from Axiles Bionics and Sylvia Perrone from MovMedix due to their industry experience with mobility enhancing products. From his expertise in prosthetics, Pierre advised about mechanical feasibility of connective implants which influenced us to determine lower body applications of our product as the most feasible approach. Furthermore, Adam Davies from OceanPhysio reaffirmed our hope that due to sustained issues with autografts, there is a large desire for both tendon and ligament reinforcements, particularly from the sporting industry.
‘Closing the loop’ between our design and what is desired…
Throughout our project we have benchmarked our success on both the synbio and graphene elements by carrying out preliminary testing and adjusting our final aims accordingly. In an attempt to close the loop between our design and desires, we have had to make compromises, moving from producing artificial synthetic tissues to a regenerative scaffold instead. Discussions with many of the companies we engaged with informed us about the biological challenges of implementation in regards to surgery, encouraging our pursuit of a shorter-term therapy.
Using human practices to inform our ethical, technical, safety and communication decisions…
Human practices are embedded into our technical framework. Through initial interactions with both silk and graphene biotech companies including Spiber and Graphenea, we were assured about the potential of these materials and the feasibility of them to be applied in biomedicine. Ethically, we ensured to ask the opinions of stakeholders and final users, such as MovMedix and physiotherapists as they could offer specialist advice on the demands of potential demographics. From this, we adapted the standard of our testing, such as for conductivity, and broadened our final aims.
Integrated Human Practices - Gold
To ensure that our research is following the modern gold standard of responsible experimentation, we implemented the AREA cycle, as proposed by UK Research and Innovation for project design and optimisation.
The AREA Framework
Figure 4 - Area framework diagram
April 5, 2022 - Bootcamp Week
Anticipate
We needed to understand what constitutes worthwhile and impactful public and stakeholder engagement so we could implement this in our project.
Engage
As an introduction to the concept of effective Human Practices our PI, Dr Chloe Singleton instigated a science communication discussion in boot camp week whereby we assessed a variety of previously used methods of scientific engagement.
Reflect
We concluded that the best approaches involved a two way dialogue whereby teams could reflect and act on feedback they received. Contact had to be relevant, purposeful and insightful to allow sculpting of a project.
Act
From this activity we decided that not only was it important for us to consult a range of professionals, companies and stakeholders but that no matter their specialisation, their advice can inform us technically, industrially and socially.
Figure 5 - Idea generation with the whole BionExe team
June 23, 2022 - Presentations
Anticipate
We filtered our ideas down to three (cadmium recycling, silk-graphene composite, synthetic antibodies) but needed advice from experienced researchers as to which projects they felt were most viable to achieve and useful to pursue.
Engage
We presented our ideas to a group of academics from the Biocatalysis Centre in concise 10 minute presentations, following this with a collaborative discussion
Reflect
The academics helped to troubleshoot concerns we had for all of our ideas. Synthetic silk was most warmly welcomed based on its novelty and the ability for the project’s success to be most easily benchmarked.
Act
Compiling this feedback we unanimously decided via a blind vote that we would pursue attempting a synthetic silk-graphene composite.
Figure 6 - Presenting our initial idea to academics.
July 7, 2022 - Spiber
Anticipate
We wanted a deeper understanding of the current market in synthetically produced materials as well as determining whether there is potential for increasing their applications in the future.
Engage
From engaging with Spiber, a sustainable materials company, we learnt that materials produced by bacterial fermentation, such as their brewed protein™ range, have great future potential. We were therefore reassured that our focus on producing a synthetic composite was aligned with trends in this market.
Reflect
From research into Spiber and similar apparel companies we felt that it is already somewhat of a crowded market. Silk composite clothing pieces are currently highly expensive and we were inspired to research more meaningful and widely applicable uses for our product.
Act
In light of this, and inspired by the biocompatible nature of spider silk, we began to explore potential biomedical applications for our composite material. The growing field of nerve tissue regeneration seemed to align with our vision for a highly conductive material and we began to aim to create artificial nerves.
July 9, 2022 - Exeter Graphene Institute
Anticipate
With the new aim of creating artificial nerves, we began to consider how to best harness graphene to optimise conductivity in our material.
Engage
As well as being optimistic and encouraging of our vision, Dr Ana Neves from the Exeter Graphene Institute gave a thorough insight into the various forms of graphene available for us to use.
Reflect
From preliminary research we decided we required graphene in particulate form rather than a sheet as this would most readily and thoroughly coat our synthetic silk fibres.
Act
From this meeting we concluded that reduced graphene oxide would be the most appropriate for binding to synthetic silk in the creation of our material. This is due to the propensity for high binding affinity of rGO in composite formation.
Figure 7 - Meeting with Dr Ana Neves from the graphene institute.
July 14, 2022 - Graphenea
Anticipate
Focussing on strength and conductivity as our two measures of success led us to start considering the various methodologies of testing these particular parameters.
Engage
Graphenea, a leading graphene manufacturer and supplier, informed us on industry standard testing. We gained expertise on ATSM testing for tensile strength and the four probe technique for determining electrical conductivity.
Reflect
After performing preliminary testing in the Exeter graphene institute we established that the four probe technique was not appropriate for our scale of sample. Therefore, we resorted to the use of a multimeter for preliminary conductivity testing.
Act
After obtaining conductivity readings when measuring the conductivity of our preliminary graphene-coated fibres, we branched out our potential application ideas to include synthetic ligaments or tendons too.
July 15, 2022 - Movmedix
Anticipate
Exploring this niche and new avenue of synthetic ligament or tendon production, we were in need of expertise to direct us on progress and innovative requirements or desires in this field.
Engage
Silvia Perrone, the marketing and development director at Movmedix, a synthetic ligament reconstruction company, informed us which specific properties are valuable and how to test for them.
Reflect
Therefore, we decided to hone our experiment to focus on enhancing elasticity, torsion, elongation and mechanical strength as well as considering how this would affect biocompatibility and the life span of the material in-vivo. The beneficial properties that silk boasts aligned with those highlighted by Silvia, encouraging our interest in this biomedical application of our composite.
Act
We decided to include tests for elasticity and tensile strength in our protocols later down the line. Furthermore, a follow up meeting was organised including Chloe, our PI, to discuss potential sponsorships/business start ups or continuation of our project after iGEM.
Figure 8 - BionExe video call meeting with Movmedix.
July 20, 2022 - Axiles Bionics
Anticipate
To further explore the potential applications of our product aside from artificial nerve creation, we considered the utility of our material within endoprosthesis.
Engage
A meeting with Pierre Cherrelle, the CEO of Axiles Bionics, revealed to us that the prospect of a seamless interface between biological components with traditional prosthetics is a distinct future possibility. He encouraged that it is more realistic to focus on developing an aid for lower-body rehabilitation due to less complexity and that these are best modelled via CAD.
Reflect
Overall we concluded that our material as an endoprosthetic component can’t currently be applied to robotic prosthetics. Our conversation with Pierre, however, helped us to reconsider or reaffirm our parameters of success with our integrated design and when carrying out material testing e.g. strength, fatigue and lifespan.
Act
We decided that aiming toward regeneration of connective tissues has the highest promise of success as the transience of scaffolds puts less pressure on the composite’s mechanical properties. We also began considering applications for peripheral nerve restoration.
July 26, 2022 - Movmedix
Anticipate
Wanting to continue to explore what the current synthetic connective tissue market requires and how our product could fit into that, we sought professional advice as to the industrial viability of our product.
Engage
We organised a follow up meeting with Movmedix and Chloe, our PI, which focussed on the business potential of our product. Silvia Perrone encouraged a potential start-up, sponsorship and collaboration (depending on our progress and final application) as well as giving great advice on the importance of gold standards and stakeholders.
Reflect
This discussion allowed us to view how our product would fit into the market. Approaching the project from a business perspective rather than a scientific one enlightened us as to how we pitch and other factors we should begin considering, e.g. costing, if we were interested in continuing our project after iGEM.
Act
We contacted Ian Archer at IBiolC, a government funded body that helps small biotech companies to scale up, to give us an idea of industrial costing.
August 5, 2022 - IBioLC
Anticipate
In light of interest in potentially developing our product into a startup we were driven into considering how we can pitch our idea from a business perspective.
Engage
We contacted IBiolC, a government funded body that helps small biotech companies to scale up industrially. We took part in a half day workshop, run by Ian Archer, into bioprocess costing.
Reflect
Our model helped us understand where the main cost of bioprocessing lies, as well as the overall profit viability of the scaled up process. We also learnt that future scaling up in silk fibre formation specifically could involve a shift from spontaneous self assembly to electro-spinning in order to increase the output.
Act
With Ian’s expertise and resources to hand we created a more ‘market ready’ pitch. Via the use of our developed process model we defined just how much it would cost to generate a unit of our final material as well as where the most significant of our costs lie.
August 8, 2022 - Quay Kinetics Physio
Anticipate
Driven into further exploration of tendon and ligament applications for our material, we decided to really hone into the specific areas of the body that we should focus on.
Engage
This consultation further encouraged a focus on upper body injuries, specifically in the hand, and reassured us of the potential of our product in supporting the healing of injuries as part of sports rehabilitation.
Reflect
Jennifer Searle from Quay Kinetics Physio informed us of the common hand injuries she sees in her clinic, including the most common soft tissue injury - A2 pulley strains in the ring finger - which is particularly common in climbers.
Act
In order to visualise how our material could be best placed for mechanical support to injuries of this nature, we started developing a digital 3D hand to model strains and movements in this area for synthetic tendons.
August 25, 2022 - Ocean Physio
Anticipate
With a view to deepen the therapeutic relevance of our product, we required more specific information on common hand injuries and their recovery times to see what is desired in this market.
Engage
We met with Adam Davies from Ocean Physio at the University of Exeter. He suggested that synthetic ligaments would benefit from the elasticity of spider silk but that both ligaments and tendons have great therapeutic relevance: particularly highlighting ACL and Achilles ruptures. He gave us invaluable insight into current injury causes, current rehabilitation methods and gaps in the market.
Reflect
After realising the prevalence of ACL injuries, we reassessed our hand fixation. It appears that applications in the lower body such as the ACL or Achilles tendon are the most valuable and sought after, however as previously informed, these pose greater mechanical challenges. A hybrid between using a skin graft and our composite could be promising. Alternatively, developing a scaffold with a shorter-life span may solve such rigorous mechanical demands.
Act
We confirmed our final aim for support of tissue regeneration instead of purely synthetic implants. This moulded our marketing and placed emphasis on specific properties to enhance regrowth including biodegradability, conductivity and biocompatibility.
Conclusion
To ensure our research is following the modern gold standard of responsible innovation, we employed the AREA framework which also ensured we gained maximum benefit from our industry and stakeholder engagement. The ‘anticipate’ criterion helped us identify what information was required for the next steps as well as ‘reflecting’ on our purposes and motivations. In turn, this helped to inform just who specifically to ‘engage’ with, during which we gained invaluable opinions and expertise from a broad range of people and employed ‘actions’ as a result. As part of the 3Rs, ‘Reflection’ helped us to consider both our goals and inspirations which in turn helped us to identify important groups to consult. More specifically, engagement surrounding ‘Responsibility’ involved considering how to innovate sensibly and sustainably as well as undertaking a discussion with end users. The knowledge gained from thorough and open communication with interviewees informed an inclusive and progressive tone within the communication of our product. Shaping our human practices around the 3Rs as well as the AREA framework facilitated the creation of feedback loops which led to broad ranging design considerations, that covered all bases. We are so grateful to everyone involved in each stage of shaping our project design creation, progression and ultimately optimisation of our product.
References
- [1] Salehi, S., Koeck, K. and Scheibel, T., 2020. Spider silk for tissue engineering applications. Molecules, 25(3), p.737.
- [2] Zhang, Q., Li, M., Hu, W., Wang, X. and Hu, J., 2021. Spidroin-Based Biomaterials in Tissue Engineering: General Approaches and Potential Stem Cell Therapies. Stem Cells International, 2021.
- [3] Is silk cruelty free, MADI apparel. 2022 https://www.madiapparel.com/blogs/news/is-silk-cruelty-free [accessed 02/09/22]
- [4] Stabenfeldt SE, García AJ, LaPlaca MC (June 2006). "Thermoreversible laminin-functionalized hydrogel for neural tissue engineering". Journal of Biomedical Materials Research Part A. 77 (4): 71
- [5] Bullough, R., Finnigan, T., Kay, A., Maffulli, N. and Forsyth, N.R., 2008. Tendon repair through stem cell intervention: cellular and molecular approaches. Disability and rehabilitation, 30(20-22), pp.1746-1751.
- [6] Anderson M, Shelke NB, Manoukian OS, Yu X, McCullough LD, Kumbar SG. Peripheral nerve regeneration strategies: electrically stimulating polymer based nerve growth conduits. Critical Reviews™ in Biomedical Engineering. 2015;43(2-3).