Boronate-containing copolymers: polyelectrolyte properties and sugar-specific interaction with agarose gel

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Chromatography

Background:

• Boronate-sugar interactions are crucial for specific molecular recognition.
• Developing materials for biomedical applications requires understanding adsorption behavior under physiological conditions.

Purpose of the Study:

• To synthesize and characterize copolymers of N-acryloyl-m-aminophenylboronic acid (NAAPBA) with acrylamide (AA), N,N-dimethylacrylamide (DMAA), and N-isopropylacrylamide (NIPAM).
• To investigate the adsorption of these boronate-containing copolymers (BCCs) onto cross-linked agarose gel (Sepharose CL-6B).
• To explore the potential biomedical applications of these copolymers based on their binding characteristics.

Main Methods:

• Synthesis of NAAPBA-based copolymers.
• Adsorption studies on Sepharose CL-6B across a pH range of 7.5-9.2.
• 1H NMR spectroscopy for determining phenylboronic acid (PBA) group percentages.
• Characterization of binding using equilibrium association constants and chromatographic capacity factors.
• Desorption studies using fructose.

Main Results:

• Copolymers adsorbed onto agarose gel via specific boronate-sugar interactions in the pH range of 7.5-9.2.
• Adsorption capacities ranged from 15-30 mg/ml gel at pH 9.2, decreasing with lower pH.
• AA-NAAPBA copolymer showed maximal adsorption capacity at pH 7.5.
• Binding was multivalent, with copolymers showing stronger adsorption than monomeric NAAPBA.
• Complete desorption was achieved with 0.1 M fructose.

Conclusions:

• The strong adsorption of AA-NAAPBA on agarose gel suggests potential for biomedical applications under physiological conditions.
• Multivalent, weak-affinity adsorption of BCCs to agarose gel serves as a model for interactions with cell membrane carbohydrates.
• These copolymers offer a promising platform for developing targeted drug delivery or diagnostic tools.