Dual functional molecular imaging probe targeting CD20 with PET and optical imaging

Area of Science:

• Biomedical Imaging
• Molecular Imaging
• Antibody Engineering

Background:

• CD20 is a key biomarker in B-cell malignancies like lymphoma.
• Developing targeted imaging agents enhances diagnostic accuracy and treatment monitoring.
• Dual-modality probes offer complementary information for comprehensive assessment.

Purpose of the Study:

• To create a novel dual-functional probe for Positron Emission Tomography (PET) and Near-Infrared Fluorescence (NIRF) imaging.
• To target the CD20 antigen, a significant marker in lymphoma.
• To validate the efficacy and cross-validation of this dual-probe's targeting capabilities.

Main Methods:

• Conjugation of anti-CD20 monoclonal antibody (mAb) NuB2 with Alexa Fluor 750 and 64Cu via a DOTA chelator.
• In vivo PET and NIRF imaging in CD20-positive Raji lymphoma-bearing mice.
• Ex vivo biodistribution studies to assess fluorescence intensity and radioactivity at multiple time points.

Main Results:

• The dual-functional probe (64Cu-DOTA-NuB2-Alexa Fluor 750) showed significantly higher uptake in Raji tumors compared to a control probe.
• A strong correlation (r=0.94) was observed between radioactivity and fluorescence intensity in organ-to-muscle ratios.
• Successful dual-modality imaging was achieved, confirming probe efficacy.

Conclusions:

• The developed mAb-based dual functional probe is effective for PET and NIRF imaging of CD20 expression.
• This dual-probe represents a feasible and promising tool for lymphoma imaging and potentially therapy monitoring.
• Cross-validation of PET and NIRF signals confirms the probe's reliability in targeting CD20-positive tumors.