“…Firstly introduced by ourselves (12)(13)(14) and advanced by Wagner et al (15,16), it could be shown that in dependence of the number, type and position of cationic groups within the macromolecule, their potential as non-viral vectors for gene delivery can dramatically be altered -from toxic compounds to highly effective yet non-toxic transfection agents (14,17,18). There are also other examples for artificial solid phase synthesized macromolecules, however the synthetic procedure is often related to a single target structure and is not necessarily applicable for the synthesis of a variety of macromolecules (19)(20)(21). We believe that solid phase synthesis has the potential for the synthesis of a large variety of synthetic macromolecules and thus introduced the term solid phase polymer synthesis.…”