PREPARATION OF MOLECULARLY IMPRINTED MAGNETIC NANOPARTICLE FOR SPECIFIC EXTRACTION OF ALKALINE PHOSPHATASE

Keywords: molecular imprinting; oriented imprinting; boronate affinity; magnetic nanoparticle; alkaline phosphatase

Glycoproteins are a large family of proteins which have great biological and clinical importance, including molecular recognition, signal transduction, cell adhesion and immune response. Many glycoproteins are important biomarkers for disease diagnosis and as therapeutic targets. However, glycoproteins are present in very low abundance in the body and coexist alongside similar molecules present at much higher abundance. So, specific recognition of glycoproteins is of great significance. Although antibodies are commonly used to solve this issue, they are associated with some apparent drawbacks, such as, difficult to prepare, poor storage stability, high cost and requiring harsh conditions for target release. Therefore, novel alternatives are highly desirable. Molecularly imprinted polymers (MIPs) are advanced functional materials with excellent selectivity, high affinity and good stability, which have been applied in various aspects such as separation, sensing and catalysis. Herein, by virtue of the boronate-affinity oriented surface imprinting approach proposed by our group^1,2, molecularly imprinted magnetic nanoparticles (MI-MNPs) have been prepared for the selective extraction of alkaline phosphatase (ALP). ALP is a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests. By using the boronic acid-functionalized MNPs as the nanocores, the template molecules were immobilized onto the boronic acid-functionalized MNPs through boronate affinity interaction. Then, a thin-layer of silica was formed to cover the templates to an appropriate thickness. After that, the templates are removed facilely by washing with an acidic solution to disrupt the boronate affinity interaction. The prepared MIPs exhibited very good specificity for ALP, and this characteristic was preserved even in a complicated real sample. Moreover, the MI-MIPs synthesized in this work were simple to prepare, stable, cost-efficient and easy to collect. Besides, the target release just needed gentle conditions. With the unique properties, the MIPs can be powerful tools for important applications such as proteomics, glycomics and disease diagnostics.

Reference

[1] Bie Z, Chen Y, Ye J, Wang S, & Liu Z. (2015). Boronate-affinity glycan-oriented surface imprinting: a new strategy to mimic lectins for the recognition of an intact glycoprotein and its characteristic fragments. Angewandte Chemie International Edition, 54(35), 10211-10215.

[2] Xing, R., Wang, S., Bie, Z., He, H., & Liu, Z. (2017). Preparation of molecularly imprinted polymers specific to glycoproteins, glycans and monosaccharides via boronate affinity controllable-oriented surface imprinting. Nature Protocols, 12(5), 964-987.