Solid-phase synthesis of molecularly imprinted nanoparticles

• Published in: Nature protocols Vol. 11; no. 3; pp. 443 - 455
• Main Authors: Canfarotta, Francesco, Poma, Alessandro, Guerreiro, Antonio, Piletsky, Sergey
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-03-2016; Nature Publishing Group
• Subjects: 631/1647/1888; 631/1647/350/354; 639/638/11/872; 639/638/549/2263; Analytical Chemistry; Binders; Binding Sites; Biological Techniques; Biomedical materials; Chemical synthesis; Computational Biology/Bioinformatics; Heterogeneity; Innovations; Life Sciences; Methods; Microarrays; Molecular Imprinting - methods; Nanoparticles; Nanoparticles - chemistry; Organic Chemistry; Polymers; Polymers - chemistry; Properties; protocol; Solid Phase Extraction - methods; Solid-Phase Synthesis Techniques - methods; Triazines - chemistry; Triazines - isolation & purification; Trypsin - chemistry; Trypsin - isolation & purification
• ISSN: 1754-2189; 1750-2799
• DOI: 10.1038/nprot.2016.030

Canfarotta
et al
. describe an elegant molecular imprinting method in which the target is immobilized on glass beads. These are then used to produce nanoparticles, with binding properties analogous to those of antibodies.
Molecularly imprinted polymers (MIPs) are synthetic materials, generally based on acrylic or methacrylic monomers, that are polymerized in the presence of a specific target molecule called the 'template' and capable of rebinding selectively to this target molecule. They have the potential to be low-cost and robust alternatives to biomolecules such as antibodies and receptors. When prepared by traditional synthetic methods (i.e., with free template in solution), their usefulness has been limited by high binding site heterogeneity, the presence of residual template and the fact that the production methods are complex and difficult to standardize. To overcome some of these limitations, we developed a method for the synthesis of MIP nanoparticles (nanoMIPs) using an innovative solid-phase approach, which relies on the covalent immobilization of the template molecules onto the surface of a solid support (glass beads). The obtained nanoMIPs are virtually free of template and demonstrate high affinity for the target molecule (e.g., melamine and trypsin in our published work). Because of an affinity separation step performed on the solid phase after polymerization, poor binders and unproductive polymer are removed, so the final product has more uniform binding characteristics. The overall protocol, starting from the immobilization of the template onto the solid phase and including the purification and characterization of the nanoparticles, takes up to 1 week.