Preparation of low molecular weight N-maleated chitosan-graft-PAMAM copolymer for enhanced DNA complexation

► Chitosan-grafted-PAMAM copolymer was prepared with simple Michael type addition reaction. ► Surface charge density increased due to increase in number of primary amine groups. ► pDNA complexation ability of chitosan markedly increases after copolymerization. ► The novel water soluble copolymers were comparatively of lower toxicity than PEI. ► The novel copolymers may be used safely as drug and gene delivery carrier.