HYDRA: A novel hydroxy and amine functionalised resin synthesised by reductive amination of PEG aldehyde and a polyamine

Abstract

A chemically inert poly(ethylene glycol) (PEG)-based resin was synthesised by reductive amination of a mixture of mono- and dialdehyde PEG₁₅₀₀ and the branched cross-linker tris(2-aminoethyl)amine. This unique concept of resin polymerisation yields a polar resin with two functionalities present (OH and NH). The resin loading could be tuned between 0.33 and 0.80 mmol OH per gram and 0.88 and 0.24 mmol NH per gram by varying the monomer composition in the polymerisation mixture. The resin was found to exhibit excellent swelling properties in a broad range of solvents, and was stable towards strongly acidic and basic conditions for weeks. Furthermore, both an octa- and a decapeptide were successfully assembled independently on the different functionalities. In addition, the resin was shown to be fully permeable to a 27 kDa protease.