title: Low molecular weight PEIs modified by hydrazone-based crosslinker and betaine as improved gene carriers.
abstract: Low-molecular-weight polyethyleneimine (LMW PEI) exhibits poorer transfection efficiency but lower cytotoxicity compared to high-molecular-weight polyethyleneimine (such as PEI 25kDa). To enhance the gene transfection performance of LMW PEI, we herein demonstrate a new strategy for modifying LMW PEI. A crosslinker containing an acid-labile hydrazone bond (hydrazone-based crosslinker) was synthesized and used to crosslink PEI 1.8kDa and convert it into higher-molecular-weight polycations. And the crosslinked polycations were further modified by incorporating a betaine monomer [N,N-dimethyl(acrylamidopropyl)ammonium propane sulfonate, DMAAPS] onto their surfaces. The molar percentages of the incorporated betaine molecules to amino groups on the polycations were determined as 21.2%, 36.0% and 77.2%, respectively. Molecular weights of the modified polycations were measured using capillary viscometry at pH 7.4 and 5.0, respectively, and the degradation of the polymers in acidic solution was confirmed. The PEIs modified with hydrazone and betaine (PEI-Hdz-DMAAPS) exhibit much lower cytotoxicity than PEI 25K, and they also show no or little hemolytic effect with their hemolysis rates around 5%. PEI-Hdz-DMAAPS21.2%/DNA and PEI-Hdz-DMAAPS36.0%/DNA complexes exhibit high transfection efficiencies, which are comparable to or higher than that of PEI 25K/DNA complex in the absence or presence of 10% serum. With these improved gene delivery properties, the PEI-Hdz-DMAAPS samples have great potential for serving as efficient gene carriers. This strategy may provide some insights for constructing some other biocompatible materials.
authors.affiliation: Department of Polymer Science, College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Fang
authors.affiliation: College of Materials Science & Engineering, State Key Lab of Luminescent Materials & Devices, South China University of Technology, Guangzhou 510640, China. Electronic address: mcfzeng@scut.edu.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Zeng
authors.affiliation: Department of Polymer Science, College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Changmin
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Polymer Science, College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China; College of Materials Science & Engineering, State Key Lab of Luminescent Materials & Devices, South China University of Technology, Guangzhou 510640, China. Electronic address: shzhwu@scut.edu.cn.
authors.forename: Shuizhu
authors.initials: S
authors.lastname: Wu
mesh_terms: D000818:Animals; D001622:Betaine / Q000737:chemistry*; D005822:Genetic Vectors; D057809:HEK293 Cells; D006367:HeLa Cells; D006461:Hemolysis; D006801:Humans; D006835:Hydrazones / Q000737:chemistry*; D008970:Molecular Weight; D011094:Polyethyleneimine / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D011817:Rabbits
chemical_list: D006835:Hydrazones; D001622:Betaine; D011094:Polyethyleneimine
keywords: Acid labile; Biocompatibility; Cytotoxicity; Gene delivery; Protein adsorption