Quantum dots are tiny nanoparticles made of semiconductors that have unusual optical properties. In medicine, they may be very useful because they emit light when stimulated by electricity or an external light source, making them easy to spot in diagnostic tests. They’re more than ten times brighter than fluorescent dyes commonly used today, potentially allowing their use to significantly improve many existing tests and systems that rely on fluorescence. A major challenge of putting quantum dots into clinical practice is how to attach them to antibodies that seek out diseases without ruining the functionality of neither the quantum dots nor the antibodies.
Researchers at the Riken research institute in Japan have now developed what seems like a foolproof way of binding antibodies with quantum dots. Previous attempts at a direct connection have led to molecules that clump together, while using a connecting protein made the resulting compound molecule too big to function normally. The Riken team built a protein that is much smaller than previous attempts, called HisGB1, and that binds better to quantum dots. “HisGB1 quantum dots can be used to simply prepare compact antibody–quantum dots conjugates that can enable highly sensitive molecular imaging,” said Takashi Jin, the lead of the research study.
To validate the new capability in practice, the researchers used attached quantum dots to antibodies that seek out the Her2 receptor commonly found on many breast cancer tumors. The result was that they able to light up the tumor samples while keeping the non-cancerous cells in the dark.
Study in journal Chemical Communications: Immunoglobulin binding (B1) domain mediated antibody conjugation to quantum dots for in vitro and in vivo molecular imaging…
Via: RIKEN…