Amphiphilic azobenzene-neomycin conjugate self-assembles into nanostructures and transports plasmid DNA efficiently into the mammalian cells

Abstract

The present study demonstrates the use of self-assembled nanostructures of cationic amphiphilic azobenzene-neomycin (a small molecule) conjugate, Azo-Neo, as delivery vector for plasmid DNA. These nanostructures efficiently condensed nucleic acid and formed more compact nanoassemblies. DLS analysis showed size and zeta potential of the resulting Azo-Neo/pDNA nanoassemblies ∼153.7nm and +7.26mV, respectively. The nanoassemblies were characterized by physicochemical techniques and evaluated for its toxicity and ability to deliver nucleic acid therapeutics. The flow cytometry results on MCF-7 and HEK293T cells revealed that Azo-Neo/pDNA nanoassemblies transfected ∼31% and 23% cells, respectively, at a w/w ratio of 250, while the standard transfection reagent, bPEI/pDNA complex, could transfect only ∼21% and 29% cells, respectively, at its best w:w ratio of 2.3. MTT and hemolysis assays showed the non-toxic nature of the projected nanoassemblies and nanostructures, respectively, at various concentrations. Further, Azo-Neo nanostructures showed efficient antibacterial activity against different strains, laboratory strain of Staphylococcus aureus (MTCC 740) as well as MRSA strains (Staphylococcus aureus ATCC 33591, ATCC 43300 and ATCC 700699). These results ensure the great potential of these nanostructures in gene delivery and antimicrobial applications.

Keywords: Antimicrobial activity; Azobenzene-neomycin; Cytotoxicity; Self-assembly; Transfection efficiency.