Abstract
In terms of nuclear decay 18F is the most ideal PET nuclide but its short t1/2 precludes its use for directly labelling whole antibodies due to their long blood residence times. Pre-targeted imaging using affinity systems such as Neutravidin™–biotin facilitates the application of short-lived nuclides by their attachment to biotin for imaging cell surface proteins targeted with Neutravidin™-conjugated antibodies.
Methods
Boroaryl functionalised biotin was prepared with a PEG linker and radiolabelled by incubation with 18F in acidified aqueous solution. Cells expressing high (SKBr3), medium (MDA-MB-453) and low (MDA-MB-468) levels of HER-2 were pre-incubated with Neutravidin™-conjugated trastuzumab, washed, and then incubated with 18F-PEG-biotin.
Results
The 18F-fluorination of boroaryl-PEG-biotin was much more efficient than reported for other versions of boroaryl-biotin. The novel 18F-PEG-biotin was demonstrated to bind to HER-2-expressing cells in-vitro pre-incubated with Neutravidin™-conjugated trastuzumab.
Conclusion
Biotin can be functionalised with boroaryl and readily 18F-radiolabelled in aqueous solution and will bind to cells pre-incubated with Neutravidin™–antibody conjugates.
Highlights
¿ Boroaryl-biotin precursor is prepared. ¿ Rapid 18F-fluorination is demonstrated. ¿ HER-2 expressing breast cancer cells pre-treated with trastuzumab–Neutravidin™. ¿ 18F-PEG-biotin binding to pre-treated cells corresponds with HER-2 expression.
Methods
Boroaryl functionalised biotin was prepared with a PEG linker and radiolabelled by incubation with 18F in acidified aqueous solution. Cells expressing high (SKBr3), medium (MDA-MB-453) and low (MDA-MB-468) levels of HER-2 were pre-incubated with Neutravidin™-conjugated trastuzumab, washed, and then incubated with 18F-PEG-biotin.
Results
The 18F-fluorination of boroaryl-PEG-biotin was much more efficient than reported for other versions of boroaryl-biotin. The novel 18F-PEG-biotin was demonstrated to bind to HER-2-expressing cells in-vitro pre-incubated with Neutravidin™-conjugated trastuzumab.
Conclusion
Biotin can be functionalised with boroaryl and readily 18F-radiolabelled in aqueous solution and will bind to cells pre-incubated with Neutravidin™–antibody conjugates.
Highlights
¿ Boroaryl-biotin precursor is prepared. ¿ Rapid 18F-fluorination is demonstrated. ¿ HER-2 expressing breast cancer cells pre-treated with trastuzumab–Neutravidin™. ¿ 18F-PEG-biotin binding to pre-treated cells corresponds with HER-2 expression.
Original language | English |
---|---|
Pages (from-to) | 1395-1400 |
Number of pages | 6 |
Journal | Applied Radiation and Isotopes |
Volume | 69 |
Issue number | 10 |
Early online date | 11 May 2011 |
DOIs | |
Publication status | Published - Oct 2011 |
Keywords
- 18F
- PET
- Neutravidin™
- breast cancer cells
- Biotin