Solving plastic pollution with proteins

The environmental impact of the materials used in clothing is significant, from the emissions and energy consumption involved with textile production, to the microplastic pollution caused through washing, to the waste generated when garments are disposed of. It is estimated that the global clothing and footwear industry represents 8–10% of global CO₂ emissions, driven primarily by overproduction and the use of fossil‑fuel‑based fibers. 

As companies and consumers seek to reduce their carbon footprint, the development of new materials and production methods are crucial endeavors. One Carnegie Mellon materials science and engineering alumnus is at the forefront of a shift in the textiles industry toward more sustainable materials in clothing manufacturing.

Melik Demirel’s work in protein science began early in his academic career, focusing primarily on computational methods. After making significant contributions to the development of the Gaussian Network Model (GNM), a coarse-grained approach for studying the structural dynamics of proteins, Demirel was invited from his home country of Turkiye to work at the National Institutes of Health. From there, he decided to pursue a doctoral degree and was drawn to Carnegie Mellon because of its reputation in materials science.  

“Carnegie Mellon excels in providing fundamental skills in computer science and materials engineering,” he noted as he recalled his student experience. While the idea of pursuing an entrepreneurial endeavor was not at the forefront of his mind during his time as a student, he credits the solid fundamentals and mentorship of his advisor, professor Anthony Rollett, with making a notable impact on his career path.

After earning his Ph.D., Demirel went on to complete postdoctoral work at Los Alamos National Laboratory, with guidance from Rollett, before his appointment to the faculty at Penn State University. At Penn State, a significant portion of his research has been dedicated to integrating manufacturing with digital technologies. After earning tenure, he spent a year at Harvard University’s Wyss Institute, where he began to appreciate the commercial potential of synthetic biology, realizing that he could bridge the gap between deep tech and market needs.

In 2018, Demirel co-founded Tandem Repeat, a start-up with the mission to address the global plastic pollution crisis by replacing synthetic fibers with biomanufactured alternatives. The company was named for tandem repeat proteins, which can have better thermal properties than conventional synthetics. Tandem Repeat’s initial fiber development, Squitex, is a material inspired by squid ring teeth proteins, which the team biomanufactures using synthetic biology as they "code" squid genes into fast-growing bacteria or yeast. 

The Squitex fibers are produced through a solution spinning process, offering high-strength and durability levels, with minimal use of natural resources and energy. The fabric also exhibits self-healing abilities as it can repair through applying pressure and a plasticizer, such as water, to mend punctures in the material in a quick manner. At the end of their life, the fibers are biodegradable. The material is intended to act as an alternative to polyester and nylon, which shed millions of tons of microplastics annually.  Tandem Repeat has established relationships with several clothing manufacturers and retailers to use Squitex in their products, but production costs were high.  

His company pivoted to the development of Procell, a fiber that is designed to be a replacement for wool. Using proteins extracted from spent beer brewing yeast, they convert the biomass into a protein pulp, which is then refined and spun into yarn. This method, called biomass fermentation, is much more affordable than Squitex production. The fabric is made so that it is able to fully dissolve in soil and oceans, and is competitive in cost to traditional wool production methods when made on a large scale.

What was once a costly, niche biotechnology is now being positioned as an affordable alternative to wool, offering superior durability, strength, and a complete absence of microplastics or PFAS.

Melik Demirel, Co-Founder, Tandem Repeat

Earlier this year, Tandem Repeat won the Future of Capitalism competition in London, beating out 650 applicants from 84 countries. The award included an investment of up to $1M, which will enable Tandem Repeat to expand its production of Procell to commercial scale from 500kg of yarn to hundreds of tons that are necessary for establishing partnerships with brands and textile mills.

“For consumers, this growth means democratizing access to high-performance materials,” said Demirel. “What was once a costly, niche biotechnology is now being positioned as an affordable alternative to wool, offering superior durability, strength, and a complete absence of microplastics or PFAS.” 

Scaling Procell fibers offers a vital solution for the textile market as brands make progress toward compliance with heightened sustainability regulations. It also improved the resilience of the supply chain in commodity markets such as textiles, which are affected by the lack of wool production in the USA. By leveraging these new materials and processes and forging partnerships with industry leaders, Tandem Repeat is creating a blueprint for transforming the global supply chain.