The Effect of Linear PEI on Characteristics and Transfection Efficiency of PEI-Based Cationic Nanoliposomes

Document Type: Original Article


1 Pharmaceutical Research Centre, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran

2 Nanotechnology Research Centre, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran

3 Pharmaceutical Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran


The development of efficient and safe carrier system to transfer DNA into cells is essential in non-viral gene therapy. The aim of the present study was to evaluate the effect of linear polyetheneimine (lPEI) (2500 Da) on the physicochemical and biological properties of lipopolyplexes constructed from liposomes and lPEI.
Materials and Methods
Different lipopolymers were synthesized from lPEI and acrylate derivatives. Nanocarriers were composed of the lipids (DOPE, DPPE and DOTAP) and the synthesized lipopolymers. After characterization of the prepared vectors by determination of size and zeta potential, transfection activity was tested in Neuro2A cells. Ethidium bromide and MTT test were used to evaluate the DNA condensation ability and cytotoxicity of vectors, respectively.
Vector’s size ranged from 95 to 337 nm and they had positive charge. The differences in DNA binding properties of lipopolyplexes were not significant. Among lipids, DOTAP showed better impact on transfection efficiency. The highest transfection activity was achieved by liposomal formulation consist of DOTAP and lipopolymer composed of lPEI and hexyl acrylate. The lipopolyplexes showed minimum cytotoxicity to the cultured cells in vitro.
The results of study confirmed that it is possible to improve gene expression using lipopolyplexes.


1. El-Aneed A. An overview of current delivery systems in cancer gene therapy. J Control Release 2004; 94:1-14.

2. Garcia L, Bunuales M, Duzgunes N, Tros de Ilarduya C. Serum-resistance lipopolyplexes for gene delivery to liver tumour cells. Eur J Pharm Biopharm 2007; 67:58-66.

3. Matsumoto M, Kishkawa R, Kurosaki T, Nakagawa H, Ichikawa N, Hamamoto T, et al. Hybrid vector including polyethylenimine and cationic lipid, DOTMA, for gene delivery. Int J Pharm 2008; 363:58-65.

4. Gao X, Kim K, Liu D. Nonviral gene delivery:What we know and what is next. AAPS J 2007; 9:E92-104.

5. Luo D, Saltzman WM. Synthetic DNA delivery systems. Nat Biotechnol 2000; 18:33-37.

6. Elouahabi A, Ruysschaert J. Formation and intracellular trafficking of lipoplexes and polyplexes. Mol Ther 2005; 11:336-347.

7. Khalil IA, Kogure K, Akita H, Harashima H. Uptake pathways and subsequent intracellular trafficking in nonviral gene delivery. Pharmacol Rev 2006; 58:32-45.

8. Chen J, Wang H, Gao J, Chen H, Liang W. Liposomes modified with polycation used for gene delivery: Preparation, characterization and transfection in vitro. Int J Pharm 2007; 343:255-261.

9. McNeil SE, Perrie Y. Gene delivery using cationic liposomes. Expert Opin Ther Pat 2005; 16:1371-1382.

10. Hanzlikova M, Soinine P, Lampela P, Mannisto PT, Raasmaja A. The role of PEI structure and size in the PEI/liposome-mediated synergism of gene transfection. Plasmid 2009; 61:15-21.

11. Yamazaki Y, Nango M, Matsuura M, Hasegawa Y, Hasegawa Y, Oku N. Polycation liposomes, a novel nonviral gene transfer system, constructed from cetylated polyethylenimine. Gene Ther 2000; 7:1148-1155.

12. Merdan T, Kopecek J, Kissel T. Prospects for cationic polymers in gene and oligonucleotide therapy against cancer. Adv Drug Deliv Rev 2002; 54:715-758.

13. Lee C, Ni Y, Chen C, Chou C, Chang F. Synergistic effect of polyethylenimine and cationic liposmes in nucleic acid delivery to human cancer cells. Biochim Biophys Acta 2003; 1611:55-62.

14. Masotti A, Moretti F, Mancini F, Russo G, Di Lauro N, Checchia P, et al. Physicochemical and biological study of selected hydrophobic polyethylenimine-based polycationic liposomes and their complexes with DNA. Bioorg Med Chem 2007; 15:1504-1515.

15. Ko YT, Kale A, Hartner WC, Papahadjopoulos-Sternberg B, Torchilin VP. Self-assembling micelle-like nanoparticles based on phospholid-polyethyleneimine conjugates for systemic gene delivery. J Control Release 2009; 133:132-138.

16. Malaekeh-Nikouei B, Malaekeh-Nikouei M, Kazemi Oskuee R, Ramezani M. Preparation, characterization and transfection efficiency of nanoliposomes modified with oligoamines as gene carrier. Nanomedicine:NBM 2009; 5:457-462.

17. Zintchenko A, Philipp A, Dehshahri A, Wagner E. Simple modifications of branched PEI lead to highly efficient siRNA carriers with low toxicity. Bioconjug Chem 2008; 19:1448-1455.

18. Lampela P, Elomaa M, Ruponen M, Urtti A, Mannisto PT, Raasmaja A. Different synergistic roles of small polyethylenimine and Dosper in gene delivery. J Control Release 2003; 88:173-178.

19. Incani V, Tunis E, Clements BA, Olson C, Kuchavski C, Lavasanifar A, et al. Palmetic acid substitution on cantianic polymers for effective delivery of plasmid DNA to bone marrow stromal cells. Biomed Mater Res 2006; 81:493-504.

20. Zuhorn IS, Bakowsky U, Polushkin E, Visser WH, Marc CA, Stuart J, et al. Nonbilayer phase of lipoplex– membrane mixture determines endosomal escape of genetic cargo and transfection efficiency. Mol Ther 2005, 11:801-810.

21. Ramezani M, Khoshhamdam M, Dehshahri A, Malaekeh-Nikouei B. The influence of size, lipid composition and bilayer Tm on the transfection efficiency of nanolipoplexes. Colloids Surf B 2009; 72:1 5.

22. Simões S, Filipe A, Faneca H, Mano M, Penacho N, Düzgünes N, et al. Cationic liposomes for gene delivery. Expert Opin Drug Deliv 2005; 2:237-254.

23. Godbey WT, Wu KK, Mikos AG. Polyethyleneimine and its role in gene delivery. J Control Release 1999; 60:149-160.

24. Fischer D, Bieber T, Li Y, Elsasser HP, Kissel T. A novel non-viral vector for DNA delivery based on low molecular weight. Pharm Res 1999; 17:1373-1379.