Lectin Recognizable Biomaterials Synthesized via Nitroxide-Mediated Polymerization of a Methacryloyl Galactose Monomer

Abstract

The preparation of poly(2-(2′,3′,4′,6′-tetra-O-acetyl-β-d-galactosyloxy)ethyl methacrylate-co-styrene) (P(AcGalEMA-co-S)) glycopolymer was performed via nitroxide-mediated polymerization using a methacrylic acid-based alkoxyamine with N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) (SG1) nitroxide as mediating agent. In the presence of a low proportion of styrene, the polymerization of the glycomonomer was conducted in a controlled fashion at 85 °C. The synthesis of the diblock copolymers was investigated via two routes by using either P(AcGalEMA-co-S) or polystyrene macroinitiators capped with SG1 nitroxide to yield P(AcGalEMA-co-S)-b-PS and PS-b-P(AcGalEMA-co-S), respectively. The AcGalEMA moieties on the diblock copolymer were deacetylated to afford carbohydrate-based amphiphilic diblock copolymer, polystyrene-block-poly(2-(β-d-galactosyloxy)ethyl methacrylate-co-styrene) (PS-b-P(GalEMA-co-S)). The self-assembling properties of PS-b-P(GalEMA-co-S) amphiphilic diblock copolymers were thoroughly exploited to obtain micellar structures and porous films. Lectin binding assays were conducted using the UV−vis spectroscopy and dynamic light scattering to test the biofunctionality of the β-galactose moieties with peanut agglutinin (PNA) on the micelles. The polymer was used to prepare honeycomb structured porous films with bioactivity. Fluorescent PNA was eventually conjugated with the sugar moieties on the porous films. Most protein was conjugated to glycopolymer inside the pore, demonstrating that this procedure can be a simple route to pattern proteins onto surfaces.