hPAMAM/DNA polyplexes, compared to viral vectors, display unique characteristics including more safety, less immune response outcomes, a simpler synthesis and an easier process. Given the importance of these polymers, hPAMAM coated with the PEGDGA copolymer was developed as a promising non-viral gene carrier. In the present study, a new complex of hPAMAM, PEGDGA-modified hyperbranched polyamidoamine (hPAMAM), was established as a versatile non-viral gene vector. The hPAMAM polymer was synthesized by using a modified one-pot method. The resulting hPAMAM-PEGDGA polymer was able to efficiently protect encapsulated-DNA against degradation for over 2 h. In addition to low cytotoxicity, the transfection efficiency of hPAMAM-PEGDGA represented much higher (p < 0.05) than that of Lipofectamine 2000 in both MCF7 and MDA-MB231 cells (an approximately 4.5-fold increase). Cellular uptake of hPAMAM-PEGDGA in MDA-MB231 cells, 254.79 ± 2.1, was significantly higher than that in MCF7 cells, 51.61 ± 6.1 (p < 0.05). EMA-labeled DNA can be clearly observed in the tumor tissue of mice receiving hPAMAM-PEGDGA/EMA-labeled DNA. However, a significant number of fluorescent spots can be found in the tumor tissue of mice receiving hPAMAM/DNA, when compared to those treated with naked hPAMAM/DNA. It has been observed that GFP is expressed more highly in hPAMAM-PEGDGA/EMA-labeled/DNA than the one in PAMAM/DNA. The results indicated that hPAMAM-PEGDGA-mediated gene delivery to breast cancer cells is a feasible and effective strategy that may offer a new therapeutic avenue as a non-viral gene delivery carrier. Notably, According to these findings, this newly-introduced copolymer, the hPAMAM-PEGDGA complex, has proved to be a promising strategy for drug or gene delivery to tissues or cell types of interest, particularly to triple-negative breast cancer.
Keywords: Breast cancer; copolymer PEG–glutamic acid; gene delivery; glutamic acid; hPAMAM; hPAMAM–Glu.