posted on 2021-05-23, 11:08authored byKirsten Cardinell
Contrast agents are frequently used in photoacoustic imaging (PAI) to study the lymphatic system. However, there is a lack of standardized approaches to evaluate agentsfor specific applications. Furthermore, validation of PAI results through post-mortem fluorescence imaging is often required. To address this, hybrid modality contrast agents would be advantageous. Using unbiased characterization experiments and analyses three commercial NIR dyes are compared: IRDye QC-1, IRDye800CW, and CF770 for the minimum detectable concentration, linear range, and stability of PA signal with prolonged laser exposure. QC-1 had the most desirable properties for quantitative lymphatic PAI specifically for glaucoma treatment testing. Therefore a hybrid tracer was developed and QC-1 alongside fluorescent dye BODIPY was labelled to bovine serum albumin (QBB). QBB tracer showed nearly identical PA properties to free QC-1 dye and maintained a strong fluorescent signal after laser exposure. The QBB tracer shows promise as a hybrid contrast agent for in vivo lymphatic PAI.