Double domain polyethylenimine-based nanoparticles for integrin receptor mediated delivery of plasmid DNA

Abstract

The objective of the present study is to conjugate L-thyroxine PEI derivative onto another PEI to compensate the amine content of the whole structure which has been utilized for the ligand conjugation. Since αvβ3 integrin receptors are over-expressed on cancer cells and there is binding site for L-thyroxine on these receptors, PEI conjugation by L-thyroxine along with restoring the PEI amine content might be an efficient strategy for targeted delivery using polymeric nanoparticles. The results demonstrated the ability of the PEI conjugate in the formation of nanoparticles with the size of around 210 nm with higher buffering capacity. The conjugated PEI derivative increased the transfection efficiency in the cell lines over-expressing integrin by up to two folds higher than unmodified PEI, whereas in the cell lines lacking the integrin receptors there was no ligand conjugation-associated difference in gene transfer ability. The specificity of transfection demonstrated the delivery of plasmid DNA through integrin receptors. Also, the results of in vivo imaging of the polyplexes revealed that 99mTc-labeled PEI/plasmid DNA complexes accumulated in kidney and bladder 4 h post injection. Therefore, this PEI derivative could be considered as an efficient targeted delivery system for plasmid DNA.

Targeted double domain nanoplex based on galactosylated polyethylenimine enhanced the delivery of IL‐12 plasmid

“…This could be the result of the coupling of two separate molecules of PEI via a linker, which increased the overall amine content of the PEI derivative. 21 This result is consistent with the buffering capacity measurement (vide supra). On the other hand, substitution of amines on PEI structure by different moieties has shown remarkable impact on its binding affinity.…”

“…In our previous study on the conjugation of two HMW PEI molecules, the size increased to around 200 nm. 21 However, in this study no significant size increase was observed. This might be the effect of the conjugation of LMW PEI, which is a smaller molecule than HMW PEI.…”

“…The preparation of succinylated PEI was performed according to our previous investigation. 21,22 Briefly, succinic anhydride was added dropwise to the 25 kDa PEI solution and incubated at room temperature. The dialysis (10,000 Da cutoff Spectra/Por membrane) was carried out against NaCl solution (0.25 M) followed by twice against water at 4 C. The fluffy materials obtained following the lyophilization were characterized by 1 H-NMR (D 2 O) spectroscopy using a Bruker Avance DRX-500 MHz NMR spectrometer (Bruker, Ettlingen, Germany).…”

“…The measurement of polymer buffering capacity was carried out using acid-base titration method as described elsewhere. 21 Briefly, PEI and its conjugate were dissolved in water in order to prepare a solution Buffer capacity (β) = Δ Acid mol /ΔpH.…”

“…In order to have high conjugation degree while maintaining significant buffering capacity, the separation of motifs responsible for targeting and plasmid condensation and delivery was considered as an alternative strategy in preparation of PEI-based gene delivery systems. 21 To achieve this goal, a double domain PEI conjugate was prepared, in which a high molecular weight PEI (HMW PEI) was coupled to a galactosylated low molecular weight PEI (LMW PEI) through a succinic acid linker. Since HMW PEI has been considered as the golden standard for polymer-based gene delivery experiments, this molecule was selected as the condensation motif.…”