Aptamers for cancer detection

Detection of cancer cells relies on the binding of specific sequences on the surface of cancer cells or soluble proteins by the use of a probe molecule bearing the complementary sequence. This is traditionally achieved by the use of antibodies. However, given the high cost of antibodies, the generation of potentially non-specific sequences and the need to raise the antibodies in animals, alternative approaches have been sought.

One such alternative is the development of synthetic molecules such as aptamers, these are designed to display the correct binding sequences and as they are synthetic do not require the use of animals. Aptamers are molecules based on nucleic acids, peptides or dendrons. Dendrons are hyperbranched structures which can be composed of amino acids, organic molecules and or saccharides. Their hyperbranched nature allows for dendrons of different sizes to be produced. The dendrons are composed of three main sections: the root - for binding the dendron to surfaces, the bulk - the branching generations of amino acids and the terminal groups at the end of the branching groups, which can be modified to include biologically active sequences. The potential to synthesise dendrons of different generations enables the control of the density of cell surface binding sequences to increase the sensitivity of the binding.