Water-soluble N-[(2-hydroxy-3-trimethylammonium)propyl]chitosan chloride as a nucleic acids vector for cell transfection

► Amino groups of chitosan were treated with glycidyltrimethylammonium chloride. ► Each modified unit contained quaternary and secondary amino groups. ► The polymer was soluble in the whole pH range and formed stable polyplexes. ► The polymer revealed relatively low cytotoxicity and high transfection efficacy. ► The modified chitosans are suitable for delivery of plasmid DNA and siRNA.