title: Poly (ethylenimine)-grafted-poly [(aspartic acid)-co-lysine], a potential non-viral vector for DNA delivery.
abstract: A potential non-viral gene-transfer vector, poly(ethylenimine)-grafted-poly[(aspartic acid)-co-lysine] (PSL), has been developed by thermal polycondensation of aspartic acid and lysine under reduced pressure. Low-molecular-mass branch poly(ethylenimine) (PEI600) was conjugated to the backbone. The chemical structure of the resulting co-polymer was identified by 1H-NMR, FT-IR, TGA and X-ray diffraction. The results of the MTT assay showed that at concentration up to 4000 nmol/l of the vector cell viability was over 80% and showed low toxicity. Electrophoretic retardation and ethidum bromide assay showed that at N/P ratios 12-15 (w/w) the DNA could be condensed and neutralized. Using the zeta potential assay we discovered that it had a high positive charge on its surface of the particle (over 30 mV). The particle sizes of the co-polymer/DNA complexes were 150-170 nm, as measured by DLS and AFM. Compared with PEI600, co-polymer/DNA complexes showed a significant enhancement of transfection activity in the absence and presence of serum in NT2 and COS7 cell lines. This means that the PEI600-PSL co-polymer is a promising candidate for gene delivery.
authors.affiliation: Institute of Bioengineering and Nanotechnology, Singapore. tangguping@yahoo.com.cn
authors.forename: Gu Ping
authors.initials: GP
authors.lastname: Tang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics; D001704:Biopolymers / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology; D019556:COS Cells; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D016895:Culture Media, Serum-Free; D004247:DNA / Q000235:genetics* / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000008:administration & dosage* / Q000648:ultrastructure; D006801:Humans; D008027:Light; D018625:Microscopy, Atomic Force; D008970:Molecular Weight; D009474:Neurons / Q000166:cytology; D019906:Nuclear Magnetic Resonance, Biomolecular; D010316:Particle Size; D010957:Plasmids / Q000648:ultrastructure; D011094:Polyethyleneimine / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology; D011107:Polylysine / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D001704:Biopolymers; D016895:Culture Media, Serum-Free; D011107:Polylysine; D001224:Aspartic Acid; D011094:Polyethyleneimine; D004247:DNA