SYNTHESIS OF 3'-PEG-MODIFIED OLIGONUCLEOTIDES ON PS-PEG TENTACLE POLYMERS

PS-PEG tentacle polymers are modified for the synthesis of oligonucleotides covalently bound to polyethylene glycol (PEG) at their 3'-position by the solid phase method without additional steps. The average stepwise coupling rates and overall yields are in the range of standard oligonucleotide synthesis. Oligonucleotides and phosphorothioates up to 20 nucleotides, modified with hexaethylene glycol (HEG), PEG(400) and PEG(1500), are synthesized in this manner. The products are characterized by capillary electrophoresis and electrospray mass spectrometry (ES-MS). These new methods are very efficient for purity control as it is required for potential antisense drugs.