Multimodality imaging probe for positron emission tomography and fluorescence imaging studies

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Radiochemistry

Background:

• Developing multimodality imaging agents is crucial for advancing cell tracking studies.
• Combining positron emission tomography (PET) and optical imaging (OI) offers complementary information.

Purpose of the Study:

• To synthesize and characterize a novel multimodality imaging agent based on bovine serum albumin (BSA).
• To evaluate the agent's utility for simultaneous PET and OI in preclinical cell tracking applications.

Main Methods:

• Bovine serum albumin (BSA) was conjugated with biotin, 5(6)-carboxyfluorescein succinimidyl ester (FAM SE), and diethylenetriamine pentaacetic acid (DTPA).
• The resulting BSA-biotin-DTPA-FAM conjugate was radiolabeled with Gallium-68 (68Ga) for PET imaging.
• In vivo studies involved injecting the FAM conjugate and 68Ga-labeled conjugate into mice, followed by fluorescence and microPET imaging.

Main Results:

• Molecular weight analysis confirmed successful conjugation of biotin, DTPA, and FAM moieties to BSA.
• Fluorescence imaging demonstrated clear localization of the FAM conjugate and 68Ga-labeled conjugate at injection sites.
• MicroPET imaging showed a distinct hotspot at the injection site for the 68Ga-labeled conjugate.

Conclusions:

• The synthesized BSA-biotin-DTPA-FAM conjugate shows potential as a versatile multiprobe for combined PET and fluorescence imaging.
• Further studies are warranted to validate its efficacy in cell tracking applications using both imaging modalities.