Microchip-Grafted P(NIPAAm-co-VPBA) with Thermoresponsive Boronate Affinity for Capture–Release of cis-Diol Biomolecules

Combination of Three Functionalized Temperature-Sensitive Chromatographic Materials for Serum Protein Analysis

We have developed a methodology to capture acidic proteins, alkaline proteins, and glycoproteins separately in mouse serum using a combination of three functionalized temperature-responsive chromatographic stationary phases. The temperature-responsive polymer poly(N-isopropylacrylamide) was attached to the stationary phase, silica. The three temperature-responsive chromatographic stationary phase materials were prepared by reversible addition-fragmentation chain transfer polymerization. Alkaline, acidic, and boric acid functional groups were introduced to capture acidic proteins, alkaline proteins, and glycoproteins, respectively. The protein enrichment and release properties of the materials were examined using the acidic protein, bovine serum albumin; the alkaline protein, protamine; and the glycoprotein, horseradish peroxidase. Finally, the three materials were used to analyze mouse serum. Without switching the mobile phase, the capture and separation of mouse serum was achieved by the combination of three temperature-responsive chromatographic stationary phase materials. On the whole, 313 proteins were identified successfully. The number of different proteins identified using the new method was 1.46 times greater than the number of proteins that has been identified without applying this method. To our knowledge, this method is the first combinatorial use of three functionalized temperature-responsive chromatographic stationary phase silica materials to separate proteins in mouse serum.

Design of pH-Responsive Polymer Monolith Based on Cyclodextrin Vesicle for Capture and Release of Myoglobin

β-Cyclodextrin vesicles (CDVs) were first introduced into the polymer monolith to prepare a pH-responsive adsorption material and used for capture and release of a cardiac biomarker, myoglobin (Myo). SH-CDV was decorated with adamantane-modified SH-octapeptide to enhance the encapsulation and release rates of Myo. Afterward, SH-CDV was introduced into the polymer monolith via click reaction to produce a pH-responsive monolith. Combining with the mass spectrometry detection, the CDV-based pH-responsive monolith was used for the enrichment of Myo glycopeptides from the mixture of glycopeptides and nonglycoprotein (bovine serum albumin) tryptsin digests reach up to 1:10 000. A limit of detection of 0.1 fmol was obtained for Myo glycopeptides in the blood sample, indicating the high sensitivity of the method. The prepared CDV-based hybrid monolith demonstrated itself to be a promising material for capture of glycoproteins in complex samples, which provides an efficient strategy for the identification and discovery of biomarkers of acute myocardial infarction.

A double responsive smart upconversion fluorescence sensing material for glycoprotein

A novel strategy was developed to prepare double responsive smart upconversion fluorescence material for highly specific enrichment and sensing of glycoprotein. The novel double responsive smart sensing material was synthesized by choosing Horse radish peroxidase (HRP) as modal protein, the grapheme oxide (GO) as support material, upconversion nanoparticles (UCNPs) as fluorescence signal reporter, N-isopropyl acrylamide (NIPAAM) and 4-vinylphenylboronic acid (VPBA) as functional monomers. The structure and component of smart sensing material was investigated by transmission electron microscopy (TEM), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopic (XPS) and Fourier transform infrared (FTIR), respectively. These results illustrated the smart sensing material was prepared successfully. The recognition characterizations of smart sensing material were evaluated, and results showed that the fluorescence intensity of smart sensing material was reduced gradually, as the concentration of protein increased, and the smart sensing material showed selective recognition for HRP among other proteins. Furthermore, the recognition ability of the smart sensing material for glycoprotein was regulated by controlling the pH value and temperature. Therefore, this strategy opens up new way to construct smart material for detection of glycoprotein.

Synthesis and polymerization of boronic acid containing monomers

This mini-review summarizes the most commonly used methods for the synthesis of phenylboronic acid-(co)polymers ranging from simple straightforward polymerization to complex post-polymerization modification.

Boronate affinity materials for separation and molecular recognition: structure, properties and applications

Boronate affinity materials, as unique sorbents, have emerged as important media for the selective separation and molecular recognition of cis-diol-containing compounds. With the introduction of boronic acid functionality, boronate affinity materials exhibit several significant advantages, including broad-spectrum selectivity, reversible covalent binding, pH-controlled capture/release, fast association/desorption kinetics, and good compatibility with mass spectrometry. Because cis-diol-containing biomolecules, including nucleosides, saccharides, glycans, glycoproteins and so on, are the important targets in current research frontiers such as metabolomics, glycomics and proteomics, boronate affinity materials have gained rapid development and found increasing applications in the last decade. In this review, we critically survey recent advances in boronate affinity materials. We focus on fundamental considerations as well as important progress and new boronate affinity materials reported in the last decade. We particularly discuss on the effects of the structure of boronate ligands and supporting materials on the properties of boronate affinity materials, such as binding pH, affinity, selectivity, binding capacity, tolerance for interference and so on. A variety of promising applications, including affinity separation, proteomics, metabolomics, disease diagnostics and aptamer selection, are introduced with main emphasis on how boronate affinity materials can solve the issues in the applications and what merits boronate affinity materials can provide.