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

A chemically inert poly(ethylene glycol) (PEG)-based resin was synthesised by reductive amination of a mixture of mono- and dialdehyde PEG(1500) and t he branched cross-linker tris(2-aminoethyl)amine. This unique concept of re sin polymerisation yields a polar resin with two functionalities present (O H and NH). The resin loading could be tuned between 0.33 and 0.80 mmol OH p er gram and 0.88 and 0.24 mmol NH per gram by varying the monomer compositi on in the polymerisation mixture. The resin was found to exhibit excellent swelling properties in a broad range of solvents, and was stable towards st rongly acidic and basic conditions for weeks. Furthermore, both an octa- an d 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.