Bacteria-Repulsive Polyglycerol Surfaces by Grafting Polymerization onto Aminopropylated Surfaces

The, formation of hydrogels on surfaces is a frequently used strategy to render these surfaces biorepulsive. Hyperbranched polyglycerol: layers are a alternative to the frequently used polyethyleneglycol layers. Here, we present a, strategy to covalently graft polyglycerol layers onto surfaces by first depositing an aminopropylsiloxane layer, which then acts as initiator layer for the ring-opening polymerization of 2-(hydroxymethyl)oxirane (glycidol). For silicon surfaces, the resulting polyglycerol layers start being biorepulsive for E. coli at a thickness of 2 nm and reach their highest bacterial repulsion (98%) at thicknesses of 7 nm or larger. This deposition strategy promises general applicability because the formation of aminopropylsiloxane layers has already been described for many materials.