Abstract:Bioorthogonal chemistry is an effective tool for measuring metabolic pathways and cellular activity, yet its use is currently limited due to the difficulty of introducing probes past the cell membrane and into the cytoplasm, especially as more complex probes are desired. Here we present a simple and minimally perturbative technique to deliver functional probes of glycolysylation into cells using a nanostructured "nanostraw" delivery system. Nanostraws provide large scale intracellular access to cells through fluidic conduits that remain small enough to minimize cell perturbation. First, we demonstrate that our platform can deliver an unmodified azidosugar, N-azidoacetylmannosamine, into cells with similar effectiveness as a chemical modification strategy (peracetylation). We then show that for an azidosugar modified with a charged uridine diphosphate group (UDP) that prevents intracellular penetration, the nanostraw platform enables its direct delivery into cells, thus bypassing multiple enzymatic processing steps. By effectively removing the cell permeability requirement from the probe, the nanostraws expand the toolbox of bioorthogonal probes to study biological processes using a single, easy-to-use platform.