Developing Turn-On Fluorescent Tools for Cellular Imaging

The development of turn-on fluorescent tools is critical for advancing cellular imaging and improving disease diagnostics. Oxidative stress, caused by an
imbalance of reactive oxygen species (ROS), leads to carbonylation of biomolecules””a chemical process associated with cancer, neurodegenerative disorders, and diabetes. Detecting these modifications requires precise and robust tools. In this project, we synthesized small-molecule fluorophores capable of selectively targeting carbonyl groups (particularly biological aldehydes) in cells using click chemistry. These probes were designed with essential properties for effective imaging, including high stability, low toxicity, fast reaction kinetics, and favorable photophysical characteristics such as large Stokes shifts and reasonable quantum yields. By introducing these novel probes into cellular systems, we aim to visualize
carbonylation processes in various biological relevant systems (i.e.; cells, bioprinting). This work contributes to understanding oxidative stress mechanisms in human diseases, advancing diagnostics, and supporting the development of innovative tools for biomedical research.

Hello everyone, my name is Amira Anwar, and my URSP project is on Developing Turn-On Fluorescent Tools for Cellular Imaging. The objective of this research is to design small-molecule fluorophores that can selectively detect carbonylation in cells, a key marker of oxidative stress. We used click chemistry to develop probes that are stable, non-toxic, and exhibit strong fluorescence properties. This work aims to advance disease diagnostics and deepen our understanding of oxidative stress-related conditions such as cancer and diabetes.
Before diving into the project details, I‘d like to take a moment to thank my mentor, Dr. Özlem Dilek, my graduate student mentor Eva-Maria Rudler, and our entire lab group for their invaluable guidance and support throughout this research. Their input has been critical to the progress of this project. Now, a bit of background on the importance of this work. Oxidative stress occurs when there‘s an excess of reactive oxygen species, or ROS, in cells, which can damage biomolecules and lead to carbonylation. So here is an image that shows a normal cell and then the ROS damaging the cell and thus the resulting cell. This chemical process is closely linked to diseases like cancer, neurodegenerative disorders, and diabetes. Detecting carbonylation is crucial for early diagnosis and for tracking disease progression. In this project, we developed small-molecule fluorescent probes that can selectively label carbonyl groups in live cells. These probes are designed to work efficiently and safely in biological systems, enabling real-time imaging of oxidative stress processes. So, to achieve this, we synthesized hydrazine-based probes using click chemistry, which allows for fast and selective reactions under mild conditions. These probes need high stability, low toxiety, rapid kinetics, and large stokes shift. So, the probes were characterized for their absorption and emission properties, ensuring they are stable, non-toxic, and photophysically robust. We tested these probes using bioprinting scaffolds to observe their fluorescence “˜turn-on‘ response when exposed to specific targets. This demonstrated their potential for real-world applications in biological imaging.Our results show that the probes were successfully synthesized and characterized. The fluorescence turn-on response observed in bioprinting scaffolds confirms the effectiveness of these probes in detecting oxidative stress markers. In conclusion, this work demonstrates the potential for using turn-on fluorescent probes to detect carbonylation processes in cells, contributing to the development of innovative diagnostic tools. This research advances our ability to study oxidative stress in disease progression, with applications that could lead to earlier diagnoses and better patient outcomes. For future work, the next steps include applying these probes to live-cell fluorescence imaging to evaluate their efficacy in biological systems. We also plan to extend their applications to tissue samples, 3D bioprinting, and design near-infrared probes for deeper imaging capabilities. This research lays the foundation for further development of fluorescent tools that can enhance our understanding of oxidative stress, its mechanisms, and its role in disease. Thank you for your attention!