No abstract

Ligand-binding assays are used for determination of minute amounts of substances in the bloodstream. Such assays require a receptor that specifically binds the substance of interest. The receptor used is often an antibody, but antibodies require special handling and a costly production procedure. We have used molecular imprinting, a method for creating selective recognition sites in synthetic polymers, to prepare polymers that mimic antibody combining sites. Molecular imprints made against theophylline and diazepam showed strong binding and cross-reactivity profiles similar to those of antibodies. Here we describe a new radiolabelled ligand-binding assay, the molecularly imprinted sorbent assay, which uses antibody mimics. This assay accurately measures drug levels in human serum, with results comparable to those obtained using a well established immunoassay technique. Antibody mimics, which are stable and readily prepared by molecular imprinting, may provide a useful general alternative to antibodies.

No abstract

Molecular imprinting is an emerging methodology for the creation of selective recognition sites in synthetic polymers. This technique entails the polymerization of functional monomers in the presence of an important molecule (template). Recent studies have shown that the polymers obtained exhibit a surprisingly high degree of stereo- and regiospecific selectivity, making the commercial use of such tailor-made separation materials in several areas, such as the chiral separation of bioactive molecules and as antibody mimics, a realistic possibility.

Molecular imprinting is a versatile technique providing functional materials able to recognize and in some cases respond to biological and chemical agents of interest. In contrast to biological antibodies, the best known receptors derived from biological combinatorial processes, molecularly imprinted polymers (MIPs) are obtained by template-directed synthesis. Thus, molecular imprinting can more properly be characterized as a "rational design" approach, allowing research and application problems to be solved. Using simple molecular building blocks, material chemists can now produce tailored synthetic materials of much improved stabilities able to replace or complement natural receptors.