IMPROVING THE TRANSGENE RESPONSE OF POLYETHYLENEIMINE THROUGH AMINO ACID DERIVATIZATION

L.T. de Marco^a, F.A. de Oliveira^b, K. Panico^b, L. Meier^a, F.C. Giacomelli^b, I.C. Bellettini^a

^a Departamento de Ciências Exatas e Educação, Universidade Federal de Santa Catarina, Blumenau, Brazil

^b Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, Brazil

([email protected])

The efficient delivery of nucleic acids requires a gene vector as they are unable to cross cell membranes.¹ Polycations and DNA can self-assemble into polyplexes enabling intracellular delivery of genetic material.² In this framework, we have evaluated the transfection efficiency and cytotoxicity of amino acid-modified polyethyleneimine (PEI) as novel vectors for gene delivery purposes. The formation of DNA-polymer polyplexes has been identified by fluorescence spectroscopy and agarose gel electrophoresis with an average size of the assemblies ranging from 100-170 nm. Biological evaluations were conducted at N/P ratios 3, 5, 10, 15, and 30, and the experimental data demonstrated that PEI substituted with arginine, cysteine and histidine are able to transfect HeLa cells to a higher extent and with lower cytotoxicity compared to the unsubstituted counterpart. PEI-Arg showed the highest values of transfection efficiency as attributed to its positive charges at nearly neutral pH (pH = 7.4). The enhanced gene delivery capacity can also be linked to the cell-penetrating feature of arginine, which is indeed a valuable tool for the intracellular delivery of bioactive molecules. The enhanced efficiency evidenced for PEI-Cys and PEI-His are possibly connected to polyplex stabilization due to the formation of bioreducible disulfide bridges, and the protonation of histidine at low pH, respectively.

References:

1. L.J.C Albuquerque et al. Macromol. Biosci. 2018, 18 (2), 1700299.
2. F.A. de Oliveira et al. J. Mater. Chem. B 2023, 11(20):4556-4571.