Integrated Human Practice
With the goal of designing a novel wearable fabric that's 100% environmentally friendly and sustainable, we aim to produce recombinant spider silk, weave it into modeled cloth, and dye it with natural dyes. Since our project requires us to combine practices from dyeing industry and fiber production industry, we have consulted people with different social roles, from traditional colorists to professors specialized in spider silk production, and visited sites from dyeing factories to companies with electrospinning technologies. With the help from these social connections, we were able to gain an integrated picture of current dyeing methods as well as fiber production as a complete assembly line in modern industry. These connections directly helped us to reflect upon the feasibility and implications of our project and made us improve upon our design accordingly. We hope these works will serve as a model which provides an example for future iGEM community.
Silk is an important symbol in Chinese culture. The intricate design and weaving technologies silk production requires make silk especially valuable among other fabric products. Because comparing with other fabrics, silk is lighter, smoother, has a shimmering surface and insulating property, as well as more difficult to produce, it gradually evolved into a symbol of the superiority and wealth in ancient Chinese society. The earliest silk fabric could only be used by the emperor, but with the rapid development of the silk industry, silk have become prevalent in Chinese society and have woven itself into Chinese culture. Silk fabric production technology was monopolized by China for hundreds of years. Later with the promotion of silk road, silk fabric became one of the most important goods in worldwide trading network before the industrial revolution. Noted with this important cultural value of silk in China, we determined to revive that silk culture by applying the latest biosynthetic technologies.
Silk Art Creative Park of China
In order to achieve the goal of producing synthetic spider silks using microorganisms, we have to first understand natural silk's distinct characteristics, productivity in current market as well as its uses throughout the Chinese history. Therefore, we arrived at the Silk Art Creative Park of China and investigated on different kinds of silk used in Chinese traditional handcrafts. Most of the silk art exhibited at the museum are naturally produced from silkworms, which we used to compare its characteristics with our own spider silk. Here, we learned silk's history, different processing methods, as well as the development of its spinning machines. This visit granted us a more profound understanding of Cocoon silk, in which we found the improvement of its strength, toughness and extensibility could all be achieved in recombinant spider silk.
"The idea of synthesizing spider silk is really novel and innovative."
Q: What are some of the challenges that the Silkworm industry is facing?
A: The problem of fading color on cloth has always been an issue for hundreds of years. Most of the time, the colored fiber has a much lower production rate than natural fiber, and the color on such fiber can easily fade over time. Currently, all the current spinning machine still requires manual operations to manipulate the machine. A fully automated machine would be able to cut the labor cost and make the silk product more approachable to the public.
Adjustments and Reflections
This visit encouraged us to take the initiative of developing a type of silk that has a strong coloration ability and strong extensibility. The guide at the silk art reminded us to consider our productivity in comparison to cocoon silk. Under their encouragements, we decided to produce some silk product samples to present our project. We were given several free cocoons for our first few dyeing trials after we finished producing our natural pigments
Under the aim of developing our project into a business startup, we consulted a mature spider silk spinning company, Bolt Thread, to compare their spider silk development with us. strengths and weaknesses.
Q: What would be an effective way to dye spider silk protein. Is dyeing spider silk similar to dying silkworm silk?
A: Pretty much the same! However, because you are excluding the fiber yourself, you can be more efficient and mix the dye directly with spider silk polymer.
Adjustments and Reflections
Their responses give us inspiration in designing a novel way to dye our spider silk. Furthermore, we developed a SWOT Analysis graph of our project comparing the information we received from Bolt Thread and Spider, another mature synthetic spider silk company, to see where do we need for future improvements
(see more in entrepreneurship)
In order to investigate how to design our desired spider silk, we contacted with influential experts in the field of synthetic spider silk production through emails and personal visits. They recommended us various research papers to provide us a deeper understanding on spider silk construction. It is their valuable advices that gave us great inspirations and encouragements to modify our own experimental designs and make ups.
At the start of our experiment, we are connected with Anna Rising, one of the co-first authors of several spider silk paper we researched on. She is a senior researcher at Karolinska Institute and at the Swedish University of Agricultural Science (SLU), specialized biomaterial as well as spider silk synthesis.
Q: Why we can't find many reports that use NT-2REP-CT structure with an alternation in pH to manually spin and form silk production? What is the uniqueness about this type of combination?
A: NT2RepCT works surprisingly well (no other recombinant silk protein has been reported to be as soluble in aqueous buffers). We have tried to use other combinations of NT and CT but have not found any better combo.
Q: We learn various buffers that can help constructing spidroin, including HFIP, changing in pH, and even NaCl with water. We hope you can provide some recommendations on spinning method for our team if we aim to weave our products into fiber.
A: Native spider silk spinning is a delicate process where the silk proteins are assembled into fibers (they do not aggregate). Therefore, I believe that in order to make truly biomimetic fibers we need to copy nature's way of making the fibers.
Adjustments and Reflections
Her responses assist us at the initial the stage of our project by answering our questions regards to the (NT+(n)Rep+CT) spider silk model, buffers used in spider silk construction, and potential effects of changing Rep sequences. These directly answered all of our questions we had when we were investigating from research papers. She confirmed that the repetitive regions are important for the mechanical properties of the fiber. Thus, we speculated an increase of REP region can strength the desired qualities for spider silk, and with her help, we successfully designed recombinant spider silks with 2rep, 4rep, and 6rep. We hope the result from these trials may serve help us to construct a removable and re-assembled model for future spider silk production.
As we finished producing our spider silk protein, we started to investigate the process of spider silk spinning. After several failures of silk spinning trials using our own make up, we started to seek help from spider silk spinning method. Several questions derived from our early experimental result led us to contact professor Meng Qing, one of the co-first authors of our primary reference research paper used during the experimental stage. As the vice president of Donghua textile University in Shanghai, he gave us valuable advices on how to further improve our experimental design and provided us insights in explaining the various result in our initial stage.
Q: In your essay, you and your collages developed modified "mini spider silk". Why aren't the original spider silk sequences used to produce spider silk?
A: In natural spider protein sequence, over 50% of that is G and A. These intense repetitions might overload the bacteria, which has less capacity than the eukaryotes, causing interruptions during DNA replications as shortages of tRNA. Thus, we optimized the original sequence by artificially decreasing the amount of repetitive protein to make synthetic spider silk production feasible.
Q: We've tried several trails of silk spinning with solution under different various PH solutions, according to professor Anna Rising's article. However, we received a glue-ish protein product rather than the actual silk. What might be the reason that caused this?
A: When we were studying the glands from spiders, we discovered their glands has condescending PH and a constantly changing ion concentration. When the spider was jumping from one side to another, the pulling force it applies on the spidroin not only form the actual silk, but also give it a secondary pull, making the silk more extended. It would be hard to stimulate all of these factors at once while keep the other variables constant. Hence, I would recommend you to develop your own hardware to have a constant control over these factors.
Adjustments and Adaptations
We discussed the practicality and sustainability of our products, which motivated us to expand our experiments to W silk and inspired us to explore more about different silk spinning methods, including manual silk spinning and electrospinning. Subsequently, we modified and updated our current spinning machine three times with different specializations (see product design). Here we would like to give special thanks and recognition to Donghua University and Professor Mengqing for helping us to test our spider silk.
In order to accomplish our project goal, we examined how to industrialized our project by visiting a dyeing factory based in Quanzhou. We were asked to give a solution to solve the problem of industrial pollution of using chemical dyes. To avoid producing waste and pollutants, we sought the alternative of these chemically synthetized materials — natural dyes. Furthermore, integrating with our public engagement, we connected with a Native American natural dyeing farm and a natural dye artist to investigate the dyeing effects of natural pigments, their current value, and their market potential in these two distinct communities. She taught our team the traditional significance of natural dye and its current applications.
After we decided to involve natural pigments as a part of our project, we visited Alemany farm, an organic farm based in San Francisco, to investigate the dyeing effects of natural pigments and their current value and market in the Native American community.
Adjustments and Reflections
From this visit, we learned that natural dyes have minimal environmental impact since most of which were derived from renewable resources. As we interviewed a lot of local artists who practice traditional hand-dyeing, we learned that the traditional dyeing industry still has great resistance to biosynthetic pigments despite most people seeing them as a future trend. Knowing how difficult it is for traditional artists produce naturally derived dye, we finally decided to design pathways that focus on over-producing natural pigment with high color tone to address this problem. (see more in public engagement)
We collaborated with a Chinese indigo artist and invited her to our lab to teach us the traditional dyeing methods, and in return we presented information on the biological process of the formation of indigo, which surprisingly help her to improve her dying techniques (for more information, see public education)
Adjustments and Reflections
From this dyeing workshop (using plant-derived dye), we learned that the process of applying the dye is complicated. A typical dye vat will need roughly 1 to 24 hours of preparation, not to mention the enormous amount of time used in plant-processing stage. Hence, we decided to approach this problem by using synthetically produced natural pigments, making us more confirmed that a quicker dyeing method is needed in the current market.
Quanzhou Dyeing factory (佳福染整)
After we finish our natural pigment productions, we started to design the optimal method we can use to apply the dyes. But several technical problems still bothered us: what is the most optimal coloration process for different kinds of fibers; under what condition the coloration of fiber yields the best quality; and what are the advantages and obstacles facing for chemical pigment industry. With these questions, the team went on a trip to one of the largest scale dye factories in Quanzhou. Our team communicated with the factory's chief manager and the research director about the sustainability of the current use of chemical dye and improvements needed in the future so that we can meet the demand from the future.
There are generally three types of dyeing methodologies, all of which requires intensive heat and pollutant chemicals that requires secondary process before released. Surprisingly, we found that a significant amount of cost in the factory is used in sewage processing, which inspired us to look deeper into the environmental issues using of chemical dyes.
Q: what is the biggest difference between natural pigments and chemical dyes when they are applied in practical use?
A: The natural pigments' ability of fixing color is worse than that of chemical dyes, not to mention natural pigments are easy to produce discoloration after cleaning. But by comparison, ours (chemical dye) are not as environmentally friendly as they were.
Adjustments and Reflections
This visit to the dyeing factory taught us how dyeing mythologies were applied in current industrialized factories. After seeing all the machines, we wondered whether we could incorporate the dyeing step within our spider silk spinning machine to achieve a greater color fixation (see make up design). Watching the different testing standards of fibers makes us realize that further improvement still needed to be made in order for us to produce an actual piece of wearable clothing.
With the goal of combing traditional cultures with the latest technologies to build a fully sustainable clothing, we have conducted field works into factories, museums and organic farms; consulted experts and mature businesses; interviewed traditional artists with various cultural backgrounds. As a result of interviewing with these shareholders, we were able to gain a complete picture of the demands from society and adjust our project accordingly. Being aware the importance of these social connection, we were able to present an integrated project to the public, emphasizing the immense possibilities that synthetic biology might bring us in the near future.
Moreover, these visits not only helped us to form a deeper understanding about the practical usages of our project, but also motivated us to engaged with the community around us, including consulting experts and interviewing potential customers, and more importantly, spreading the positivity of using synthetic biology to solve worldwide problems. We believe our project would flourish as the era of synthetic biology comes.