文摘
Hyperbranched poly(amino ester)s containing tertiary amines in the core and primary, secondary, and tertiaryamines in the periphery, respectively, were evaluated for DNA delivery in vitro. The same core structure facilitatedthe investigation on the effects of the terminal amine type on the properties of hyperbranched poly(amino ester)sfor DNA delivery. The hydrolysis of the poly(amino ester)s was monitored using 1H NMR. The results reflectedthat the terminal amine type had negligible effects on the hydrolysis rate but was much slower than that of linearpoly(amino ester)s, probably due to the compact hyperbranched spatial structure preventing the accessibility ofwater. In comparison with PEI 25 K, the hyperbranched poly(amino ester)s showed much lower cytotoxicity inCos7, HEK293, and HepG2 cells. Gel electrophoresis indicated that poly(amino ester)s could condense DNAefficiently, and the zeta potentials and sizes of the complexes formed with different weight ratios of hyperbranchedpoly(amino ester)s and DNA were measured. Remarkably, all the hyperbranched poly(amino ester)s showed DNAtransfection efficiency comparable to PEI 25 K in Cos7, HEK293, and HepG2 cells regardless of the terminalamine type. Therefore, the terminal amine type had insignificant effects on the hydrolysis rate, cytotoxicity, DNAcondensation capability, and in vitro DNA transfection efficiency of the hyperbranched poly(amino ester)s.
