Related Experiment Video
Updated: Apr 20, 2026
Cerenkov Luminescence Imaging CLI for Cancer Therapy Monitoring
Published on: November 13, 2012
Quantum dots-bevacizumab complexes for in vivo imaging of tumors
Maria Gazouli1, Penelope Bouziotis2, Anna Lyberopoulou3
1Department of Basic Biological Science, Laboratory of Biology, School of Medicine, University of Athens, Athens, Greece 2nd Department of Radiology, Attikon University Hospital, Athens, Greece mgazouli@med.uoa.gr.
Background/Aim:
The basic role of vascular endothelial growth factor (VEGF) in cancer is underscored by the approval of bevacizumab for first-line treatment of cancer patients. Recent anticancer therapeutics based on active tumor targeting by conjugating tumor-specific antibodies has become of great interest in oncology. Current progress in nanomedicine has exploited the possibility of designing tumor-targeted nanocarriers able to deliver specific molecule payloads in a selective manner to improve the efficacy and safety of cancer imaging and therapy. We herein aimed to determine the targeting ability of bevacizumab-conjugated quantum dots (QDs) in vitro and in vivo.
Materials And Methods:
We used QDs labeled with bevacizumab, in various in vitro experiments using cell lines derived from colorectal cancer (CRC) and breast cancer (BC). For a competition study of QD-bevacizumab complex and bevacizumab, the cells were pre-treated with bevacizumab (100 nmol/L) for 24 h before exposure to the QD-bevacizumab complex. The breast cancer cells (MDA-MB-231) were injected to 9 nude mice to make the xenograft tumor model. The QD-bevacizumab complex was injected into the tumor model and fluorescence measurements were performed at 1, 12, and 24 h post-injection.
Results:
Immunocytochemical data confirmed strong and specific binding of the QD-bevacizumab complex to the cell lines. The cells pre-treated with an excess of bevacizumab showed absence of QD binding. The in vivo fluorescence image disclosed that there was an increased signal of tumor after the injection of QDs. Ex vivo analysis showed 3.1 ± 0.8%, 28.6 ± 5.4% and 30.8 ± 4.2% injected dose/g accumulated in the tumors at 1, 12 and 24 h respectively. Tumor uptake was significantly decreased in the animals pretreated with excess of bevacizumab (p=0.001).
Conclusion:
In conclusion, we could successfully detect the VEGF-expressing tumors using QDs-bevacizumab nanoprobes in vitro and in vivo, opening new perspectives for VEGF-targeted non-invasive imaging in clinical practice.
Insights
Bevacizumab-conjugated quantum dots (QDs) show specific targeting of vascular endothelial growth factor (VEGF)-expressing tumors in vitro and in vivo. This nanomedicine approach offers a promising tool for non-invasive cancer imaging and therapy.
Area of Science:
- Oncology
- Nanomedicine
- Molecular Imaging
Background:
- Vascular Endothelial Growth Factor (VEGF) plays a crucial role in cancer, with bevacizumab approved for treatment.
- Tumor-specific antibody-drug conjugates are of significant interest in oncology.
- Nanomedicine enables targeted delivery of payloads for improved cancer imaging and therapy.
Purpose of the Study:
- To evaluate the in vitro and in vivo targeting ability of bevacizumab-conjugated quantum dots (QDs).
- To assess the potential of these nanoprobes for detecting VEGF-expressing tumors.
Main Methods:
- Quantum dots (QDs) were conjugated with bevacizumab.
- In vitro experiments utilized colorectal and breast cancer cell lines.
- In vivo studies involved a breast cancer xenograft mouse model, with fluorescence measurements at various time points post-injection.
Main Results:
- Bevacizumab-conjugated QDs demonstrated specific binding to cancer cell lines.
- In vivo imaging revealed increased tumor signal after QD injection.
- Ex vivo analysis showed significant tumor accumulation of QDs, which was reduced by pre-treatment with excess bevacizumab.
Conclusions:
- Bevacizumab-conjugated QDs successfully detected VEGF-expressing tumors in vitro and in vivo.
- This approach opens new avenues for non-invasive, VEGF-targeted cancer imaging.
- The study highlights the potential of nanoprobes for clinical applications in oncology.
