We introduce a new class of enzyme-derived polymer brush with extraordinary thickness and regenerative capacity. The brush fabrication leverages the rapid, processive polymerization kinetics of hyaluronan synthase in order to generate hyaluronan brushes with heights reaching up to 25 μm. We report the characterization of the brush grafting density, concentration profile, molecular weight distribution and interaction with nanoparticles. Further, we demonstrate sophisticated manipulation of the brush height, using start-stop control of the enzyme, and introduce a method to sculpt the brush topography (and grafting density) via photopatterning that generates localized reactive oxygen species which in turn locally eliminate the polymer anchorage. Recent efforts demonstrate that azide-modified sugar monomers can be integrated into the hyaluronan polymer by the synthase. We demonstrate brush modification leveraging these clickable groups. Last, possible applications of the ultra-thick brushes will be briefly discussed, ranging from fundamental studies of polymer physics to stimulus responsive materials to anti-microbial coatings.

<b>Top Left</b>: Confocal sideview image of ~20 μm thick hyaluronan brush excluding 200nm particles. <b>Bottom Left</b>: Fluorescently-labeled hyaluronan brush on 8 micron glass sphere. <b>Right</b>: Plot of hyaluronan polymer brush height versus synthesis time on planar and spherical surfaces (in 125 mM NaCl).<b> Insert: </b>Schematic of hyaluronan synthase enzyme responsible for brush synthesis..

Top Left: Confocal sideview image of ~20 μm thick hyaluronan brush excluding 200nm particles. Bottom Left: Fluorescently-labeled hyaluronan brush on 8 micron glass sphere. Right: Plot of hyaluronan polymer brush height versus synthesis time on planar and spherical surfaces (in 125 mM NaCl). Insert: Schematic of hyaluronan synthase enzyme responsible for brush synthesis..

Blair Brettmann

Georgia Tech

Appearances