This project will focus on the preparation of polyalkeleneimines through a recently discovered method to selective hydrolyze poly(2-oxazoline)s, for which a patent was filed. In this project we will further explore the scope of this patent and generate additional examples to support the broad claims. Furthermore, the project will focus on the preparation of block copolymers consisting of a non-ionic poly(2-oxazoline) block and a cationic polyalkyleneimine block for the preparation of shielded polyplexes with oligonucleotides. The transfection efficiency of the resulting polyplexes will be investigated.