McGowan Institute for Regenerative Medicine affiliated faculty members Jason Shoemaker, PhD, assistant professor of chemical and petroleum engineering, and Sanjeev Shroff, PhD, Distinguished Professor and Gerald E. McGinnis Chair of Bioengineering, were among the group of faculty advisors who supported a team of University of Pittsburgh undergraduates in the 2020 International Genetically Engineered Machine (iGEM) competition. This contest is an annual synthetic biology research competition in which teams from around the world design and carry out projects to solve an open research or societal problem. More than 250 teams participated in the organization’s first Virtual Giant Jamboree, and the Pitt undergraduate group received a gold medal for their project titled “Bluetooth Bacteria.” This year’s group was also one of three teams that were nominated for “Best Foundational Advance Project.” This is the first time a Pitt iGEM team has been nominated for an award at the iGEM competition.
The team included one Swanson School of Engineering student: Lia Franco, a chemical engineering junior. Other members included Sabrina Catalano, a senior molecular biology student; Dara Czernikowski, a senior biological sciences student; Victor So, a senior microbiology and English literature student; and Chenming (Angel) Zheng, a junior molecular biology student.
“This sort of non-invasive technology could be used for timed drug release, synthetic organ and neuron stimulation, or even industrial applications,” Ms. Czernikowski said. “We first considered optogenetics, which uses light to manipulate cell behavior, but this strategy cannot target deep tissue without risky invasive methods, so we needed to change our approach.”
The team ultimately decided to attach magnetic nanoparticles to the surface of bacteria and stimulate them with an alternating magnetic field (AMF). The nanoparticles react to the AMF stimulation and dissipate heat, causing the temperature of the bacterium’s cytoplasm to rise. They then used a protein dimer to act as a “bio-switch” to control gene expression.
“At lower temperatures, the protein dimers bind to a target DNA sequence and turn off gene expression, but at higher temperatures, heat causes the proteins to un-dimerize,” Ms. Catalano explained. “In its un-dimerized state, it can no longer inhibit gene expression, turning the system on. The change in temperature is controlled by the stimulation of magnetic nanoparticles with AMF, allowing wireless control of gene expression in bacteria.”
The team hopes that there is therapeutic potential for their design but recognizes that they need to improve spatial control in order to match techniques like optogenetics. They would like to improve their design to use localized heating that could selectively target one bacterium or a specific region of the cytoplasm. They plan to continue development during the upcoming semester.
Another unique aspect of their project is the “Bluetooth Bacteria Podcast” – a casual and conversational podcast that seeks to educate the general population on topics and current developments in synthetic biology.
“One of our main project goals was effective science communication,” said Ms. Catalano. “Because COVID-19 limited our ability to teach synthetic biology in person, we thought it would be fun to make a podcast as it is accessible to a wide audience. It gave us the opportunity to hear from iGEM teams all over the world, including France, London, and India.”
The team published two episodes every week, and they are available on Apple Podcast or Spotify. Listen to one of their episodes here.