title: Influence of hydroxyl groups on the biological properties of cationic polymethacrylates as gene vectors.
abstract: In this study poly(aminoethyl methacrylate) (PAEMA), poly(3-amino-2-hydroxypropyl methacrylate) (PAHPMA), poly(2-(2-aminoethylamino)ethyl methacrylate) (PAEAEMA) and poly(3-(2-aminoethylamino) 2-hydroxypropyl methacrylate) (PAEAHPMA) were synthesized using atom transfer radical polymerization to evaluate the effect of hydroxyl groups on the relative properties of cationic polymeric gene vectors. The results of heparin displacement assays showed that PAHPMA possessed a stronger binding capacity than PAEMA. PAHPMA/DNA complexes and PAEAHPMA/DNA complexes had lower zeta potentials than those of PAEMA and PAEAEMA. MTT assay results indicated that PAHPMA and PAEAHPMA exhibited obviously lower cytotoxicities than PAEMA and PAEAEMA. Subsequently, in vitro gene transfection studies in 293T cells without serum showed that PAHPMA exhibited a lower transfection efficiency than PAEMA and PAEAHPMA/DNA complexes possessed a similar transfection efficiency to PAEAEMA/DNA complexes. Moreover, PAHPMA and PAEAHPMA retained similar transfection efficiencies in DMEM with 10% serum, but PAEMA and PAEAEMA showed slightly lower transfection efficiencies than in the absence of serum. The reason for these phenomena might be attributed to the introduction of hydroxyl groups into PAHPMA and PAEAHPMA, i.e. the existence of hydroxyl groups might increase the binding capacity to DNA and at the same time decrease the surface charge of the polymer/DNA complexes due to the formation of hydrogen bonds between the polymers and DNA. Therefore, a lower zeta potential and stronger binding ability may result in a lower gene transfection efficiency. This effect of hydroxyl groups decreased with increasing amino group density on the polymer.
authors.affiliation: Key Laboratory of Biomedical Polymers of Ministry of Education, College of Chemistry and Molecular Science, Wuhan University, Wuhan, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Ma
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Zhe-fan
authors.initials: ZF
authors.lastname: Yuan
authors.forename: Ren-xi
authors.initials: RX
authors.lastname: Zhuo
mesh_terms: D002460:Cell Line; D002850:Chromatography, Gel; D005822:Genetic Vectors; D006801:Humans; D017665:Hydroxyl Radical / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011109:Polymethacrylic Acids / Q000008:administration & dosage* / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014162:Transfection
chemical_list: D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D017665:Hydroxyl Radical