Bioinspired Water-soluble Polymers with Grafted Polyamine Chains: Synthesis and Complexation with Oligonucleotides

The siliceous frustules of diatom algae contain complex proteins known as silaffins, which consist of a peptide chain with grafted polyamine chains. These polyamines contain twenty or more nitrogen atoms with trimethylene groups between the nitrogens. We synthesized a set of polymers containing grafted long-chain polyamine fragments by using acryloyl chloride (ACh) polymers and activated acrylic acid copolymers as the starting materials. The new polymers contained 0.05 mol%−3.2 mol% of polyamine chains, which corresponded to 0.06−3.56 mmol·g −1 amine groups. The new amine-containing polymers formed complexes with short (19-21-mer) deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) strands, and these complexes penetrated into model yeast cells and A549 lung cancer cell. This study demonstrates the potential of these species based on long-chain polyamines to serve as novel gene delivery systems.