Development of photocrosslinked sialic acid containing polymers for use in Aβ toxicity attenuation

β-Amyloid peptide (Aβ), the primary protein component in senile plaques associated with Alzheimer's disease (AD), has been implicated in neurotoxicity associated with AD. Previous studies have shown that the Aβ-neuronal membrane interaction plays a crucial role in Aβ toxicity. More specifically, it is thought that Aβ interacts with ganglioside rich and sialic acid rich regions of cell surfaces. In light of such evidence, we have hypothesized that the Aβ-membrane sialic acid interaction could be inhibited through use of a biomimic multivalent sialic acid compound that would compete with the cell surface for Aβ binding. To explore this hypothesis, we synthesized a series of photocrosslinked sialic acid containing oligosaccharides and tested their ability to bind Aβ and attenuate Aβ toxicity in cell culture assays. We show that a polymer prepared via the photocrosslinking of disialyllacto-N-tetraose (DSLNT) was able to attenuate Aβ toxicity at low micromolar concentrations without adversely affecting the cell viability. Polymers prepared from mono-sialyl-oligosaccharides were less effective at Aβ toxicity attenuation. These results demonstrate the feasibility of using photocrosslinked sialyl-oligosaccharides for prevention of Aβ toxicity in vitro and may provide insight into the design of new materials for use in attenuation of Aβ toxicity associated with AD.