NEW, RELIABLE ROUTES TO PROTEIN IMPRINTED POLYMERS

Molecularly imprinted polymers are crosslinked polymers formed in the presence of a template (or target) molecule. Template removal produces complementary cavities (binding sites) that can selectively rebind the molecule. First described by G. Wulff in 1972, this technology has been widely employed to bind low molecular weight substances and has found commercial application as high-selectivity, solid phase extraction cartridges. The synthesis of protein imprinted polymers (PIPs) requires fundamentally different conditions and, although there are numerous publications, the efforts in this field have been far less successful.

Semorex has developed new approaches for PIP synthesis that include libraries of proprietary tyrosine-based and other functional monomers. The monomer-protein affinities are validated and characterized prior to PIP synthesis, using techniques such as Surface Plasmon Resonance and MicroScale Thermophoresis. With these methodologies, monomers with high affinity for lysozyme and ricin B-chain (RBC) were successfully identified. Selected tyrosine- and galactosamine-based functional monomers were shown to strongly interact with lysozyme and RBC, respectively, enabling the robust synthesis of PIPs. A novel ELISA-based assay was also developed in order to characterize the lysozyme and RBC imprinted polymers. The selectivity and binding parameters of these PIPs are significantly superior to those thus far reported. Furthermore, characterization of these PIPs addresses all of the pitfalls mentioned in a critical review of this field [E. Verheyen, et. al. Biomaterials 2011, 32, 3008].

PIPs are stable and more resistant to heat and microbial degradation than antibodies; therefore, they have great potential as a platform for broad biomedical, defense and security applications. The reported results advance the realization of these applications.

Acknowledgements: We thank the Israel Ministry of Absorption for a Grant to D. Dweck.