Bioengineering Functional Copolymers. VIII. Stimuli-Responsive Boron-Containing Graft Copolymers and Their Poly ethylene imine Macrocomplexes and DNA Conjugates

Abstract

New boron-containing graft copolymers and their poly ethylene imine PEI macrocomplexes were synthesized byamidolysis of poly N-isopropylacrylamide-co-maleic anhydride s [poly NIPA-co-MA s] with ethanolamine ester ofdiphenylboronic acid EAPB , and following complexation of graft copolymers with poly ethylene imine PEI ,respectively. The structure, compositions and properties stimuli-responsive, polyelectrolyte and thermal behavior ofsynthesized copolymers were characterized by FTIR,1H {13C} NMR and UV spectroscopy, viscometry, DSC and TGAanalyses. It was shown that under given conditions pH, temperature and grafting degree , these H-bondingmacrocomplexes with hydrophobic diphenylborate side chain groups in aqueous solutions undergo a reversiblecooperative conformational transition which is provided a promising possibility of adjusting the hydophobic–hydrophilicbalance in the studied graft copolymer systems. Fluorescence measurements indicated that poly[ NIPA-co-MA -gEAPB]/PEI macrocomplex easily transferred to the HELA tumor cells, and showed low cytotoxicity against a normalcell line. Obtained results, especially stimuli-responsive and very high transferable behavior allow use these boroncontaining graft copolymer systems as non-viral vectors in gene- and bioengineering processes and drug deliverysystems, as well as in boron neutron capture therapy