In vivo fluorescence imaging for cancer diagnosis using receptor-targeted epidermal growth factor-based nanoprobe

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Oncology

Background:

• Receptor-targeted imaging is a key strategy for human cancer diagnosis.
• Epidermal growth factor receptor (EGFR) is a significant target for cancer imaging.
• Existing imaging agents, like EGFR antibodies, can be large and slow to accumulate in tumors.

Purpose of the Study:

• To develop a novel epidermal growth factor-based nanoprobe (EGF-NP) for in vivo optical imaging of EGFR.
• To evaluate the specificity, cellular uptake, and tumor accumulation of the EGF-NP.
• To compare the performance of EGF-NP with traditional EGFR antibody-based imaging agents.

Main Methods:

• Fabrication of a self-quenched EGF-NP by conjugating a near-infrared (NIR) fluorophore (Cy5.5) and a quencher (BHQ-3) to epidermal growth factor (EGF).
• In vitro evaluation using time-lapse imaging to monitor cellular uptake and specificity.
• In vivo studies in tumor-bearing mice to assess NIR fluorescence intensity and tumor accumulation after intravenous injection.

Main Results:

• The EGF-NP demonstrated high specificity for EGFR and rapid internalization into EGFR-expressing cells.
• Strong fluorescence signals were observed in EGFR-expressing cells upon EGF-NP uptake and lysosomal degradation.
• EGF-NP exhibited faster signal accumulation in tumors compared to Cetuximab-Cy5.5 conjugates, attributed to its low molecular weight and rapid clearance.

Conclusions:

• The developed self-quenched, EGF-based nanoprobe is effective for in vivo optical imaging of EGFR.
• EGF-NP offers advantages in terms of speed and tumor penetration compared to antibody-based probes.
• This EGF-NP holds potential for the diagnosis of various cancers.