title: Bioreducible poly(amido amine)s with different branching degrees as gene delivery vectors.
abstract: Based on the knowledge that cationic polymers with different topographical structures behave differently in gene transfection process, herein, we synthesized three biodegradable poly(amido amine)s (PAAs) with the same repeating units and molecular weights except for degree of branching: linear PAA (LPAA), low-branched PAA (LBPAA), and high-branched PAA (HBPAA). We found that LBPAA could more effectively compact pDNA into positively charged nanoparticles than both HBPAA and LPAA. LBPAA polyplexes had the highest transfection efficiency among the three PAA polyplexes, and the difference in transfection efficiency is mainly attributed to the endocytosis rate. The cytotoxicity of PAAs was negligible at the transfection doses, probably due to the degradable disulfide bonds. Therefore, we could use branching as a parameter to simply tune a polymer's cellular uptake behavior and transfection efficiency.
authors.affiliation: Center for Bionanoengineering and the State Key Laboratory for Chemical Engineering, Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Xinpeng
authors.initials: X
authors.lastname: Ma
authors.forename: William
authors.initials: W
authors.lastname: Murdoch
authors.forename: Maciej
authors.initials: M
authors.lastname: Radosz
authors.forename: Youqing
authors.initials: Y
authors.lastname: Shen
mesh_terms: D002460:Cell Line; D016503:Drug Delivery Systems; D018014:Gene Transfer Techniques; D006801:Humans; D053758:Nanoparticles; D010957:Plasmids / Q000378:metabolism; D011073:Polyamines / Q000138:chemical synthesis / Q000378:metabolism*
chemical_list: D011073:Polyamines