A collaborative team led by Harvard’s Wyss Institute has pioneered a groundbreaking synthetic biology platform to design high-contrast fluorescent biosensors, promising significant advancements in disease diagnostics and environmental monitoring.
In a pivotal advancement for medical diagnostics and environmental health monitoring, researchers led by Harvard’s Wyss Institute for Biologically Inspired Engineering have developed an innovative platform that simplifies the creation of highly efficient fluorescent biosensors. These biosensors, which can detect specific proteins, peptides and small molecules by dramatically increasing their fluorescence upon binding to targets, represent a major leap forward in synthetic biology.
Biosensors, devices utilizing biological molecules to identify target substances, have expansive applications in detecting disease biomarkers, monitoring biological processes and identifying environmental toxins.
Traditional fluorescent biosensors, however, face challenges due to their always-on fluorescent probes, necessitating extensive washing steps to isolate accurate signals.
The newly developed binding-activated fluorescent nanosensors overcome these hurdles by only lighting up upon target binding. This transformative approach enhances the contrast of these biosensors, making them more efficient and practical for real-world applications.
“We have long worked on expanding the genetic code of cells to endow them with new capabilities to enable research, biotechnology and medicine in different areas, and this study is a highly promising extension of this endeavor in vitro,” George Church, a professor of genetics at Harvard Medical School and professor of health sciences and technology at Harvard and MIT and lead author of the study, said in a news release.
The key to this breakthrough lies in novel fluorogenic amino acids (FgAAs) integrated into target-binding small protein sequences through an innovative genetic code expansion technique. This process, combined with high-throughput sensor screening, validation and directed evolution, allows for the rapid and cost-effective production of high-contrast biosensors.
Church emphasized the platform’s disruptive potential to benefit numerous biomedical fields. The platform can transform protein binders into nanosensors with remarkable speed, increasing fluorescence up to 100-fold in less than a second, which is a significant improvement over existing technologies.
“This novel synthetic biology platform solves many of the obstacles that stood in the way of upgrading proteins with new chemistries, as exemplified by more capable instant biosensors and is poised to impact many biomedical areas,” added Church.
Erkin Kuru, a research fellow in the Church Lab at Harvard’s Department of Genetics and co-first and co-corresponding author, highlighted the team’s progress during the pandemic, initially envisioning an “instant COVID-19 diagnostic” by creating nanosensors targeting the SARS-CoV-2 Spike protein.
The team then expanded the use of their platform to engineer nanosensors for various molecular targets, showcasing its versatility and potential impact on diagnostics and therapeutic development.
Moreover, the platform’s second iteration significantly enhances high-throughput capabilities by using engineered cell-free processes and pre-fabricated synthetic amino acids with fluorogenic scaffolds, accelerating the synthesis and testing of millions of nanosensor candidates at once.
“We wanted to expand our molecular design space much further by increasing the platform’s high-throughput capabilities,” added Kuru, which they achieved by retrofitting the ribosome to incorporate synthetic amino acids, allowing rapid nanosensor production and immediate application without additional purification steps.
The research team employed directed evolution to further refine the nanosensors, optimizing their affinity and specificity for distinct targets, including newer variants of the SARS-CoV-2 virus.
“This is an important step forward in our capabilities to quickly design low-cost fluorescent biosensors for real-time disease monitoring and with huge potential for diagnostics and precision medicine,” Marc Vendrell, an expert in translational chemistry and biomedical imaging at the University of Edinburgh and co-corresponding author, said in the news release.
The impact of this technology promises to redefine diagnostic and therapeutic strategies, offering faster, more efficient and cost-effective solutions to complex biomedical challenges.
The study, published in the journal Nature Communications, includes contributions from researchers Subhrajit Rout, Isaac Han, Abigail Reese, Thomas Bartlett, Fabio De Moline and others.