Oligoamines grafted hyperbranched polyether as high efficient and serum-tolerant gene vectors

To develop low toxic, high efficient, and excellent serum-tolerant polycation gene delivery systems, a series of oligoamines grafted hyperbranched polyether (oligoamines-g-HBP) were synthesized by conjugating different oligoamines, including triethylenetetramine (TETA) and tetraethylenepentamine (TEPA), onto COOH-functionalized hyperbranched poly(3-ethyl-3-oxetanemethanol). It was found that oligoamines-g-HBP exhibited good buffering capacity, strong DNA binding and high resistance against protein adsorption. In vitro cytotoxicity measurement indicated that oligoamines-g-HBP had much lower cytotoxicity as compared with 25 kDa PEI. The transfection efficiency of TEPA-g-HBP/DNA complexes at a certain N/P ratio was significantly higher than that of 25 kDa PEI/DNA complexes. Interestingly, it was found that TEPA-g-HBP had much improved serum-tolerant capability as compared with 25 kDa PEI even when serum concentration was increased to 30%. Confocal laser images further showed that the amount of YOYO-1 labeled DNA in nuclei got increased with increasing the number of secondary amino ethylene groups in oligoamines-g-HBP. The oligoamines-g-HBP presented great potential as gene delivery vectors for further clinical applications.

Bilayer matrix composed of polycation/DNA complex and sodium alginate gel as a tumor cell catcher

A bilayer matrix consisting of TABP-SS/DNA complexes and sodium alginate gel is formed via electrostatic interaction. In vitro cell adhesion, proliferation and transfection of the bilayer matrix are investigated in HepG2, HeLa and COS7 cells. Results show that this matrix can only promote tumor cell attachment and growth. Compared with normal cells, the bilayer matrix exhibits significantly higher transfection efficacy in tumor cells. Cell co-culture competitive transfection assay shows that the cell uptake of TABP-SS/DNA complexes is significantly enhanced in tumor cells rather than normal cells under the co-culture competitive condition, which confirms that TABP-SS/DNA complexes have strong tumor cell selectivity and tumor targeting transfection ability.