Cynthia Spires

2019 Best Biological Publication Imaging Award

The 2019 Best Biological Imaging Publication was awarded to Cynthia Spires, a PhD candidate with Professor B. Smith in the Department of Chemistry.  Cynthia and coworkers published a paper entitled "Paired Agent Fluorescence Imaging of Cancer in a Living Mouse Using Preassembled Squaraine Molecular Probes with Emission Wavelengths of 690 and 830nm".

New imaging methods were evaluated with targeted fluorescence probes for imaging cancer in a living mouse model. First, Single Agent Imaging (SAI) experiments compared tumor imaging performance of a targeted probe and untargeted probe in separate mouse cohorts. Subsequently, a mock surgery was performed that completely removed the fluorescently labeled tumor. Furthermore, there was imaging evidence for enhanced tumor accumulation of the targeted probe, but there was moderate scatter in the data due to tumor-to-tumor variability. A subsequent Paired Agent Imaging (PAI) study co-injected a binary mixture of targeted probe (with emission at 690 nm) and untargeted probe (with emission at 830 nm) into the same tumor-burdened animal. The pairing provides a correction factor that accounts for tumor-to-tumor variability in nonspecific probe uptake with statistically higher tumor uptake of the targeted probe using a much smaller cohort of mice. The imaging data from the PAI experiment was analyzed to determine the targeted probe’s Binding Potential (BP) for available integrin receptors within the tumor tissue. In addition, pixelated maps of BP within each tumor indicated a heterogenous spatial distribution of BP values. PAI is a promising new way to evaluate targeted fluorescent probes and eventual use in clinical applications.