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. 2014 Dec 12;19(12):20731-50.
doi: 10.3390/molecules191220731.

Investigation of dendriplexes by ion mobility-mass spectrometry

Emma-Dune Leriche  1 , Marie Hubert-Roux  1 , Carlos Afonso  1 , Catherine M Lange  1 , Martin C Grossel  2 , Florian Maire  1 , Corinne Loutelier-Bourhis  3
Affiliations

Investigation of dendriplexes by ion mobility-mass spectrometry

Emma-Dune Leriche et al. Molecules. .

Abstract

Highly branched polyamidoamine (PAMAM) dendrimers presenting biological activities have been envisaged as non-viral gene delivery vectors. They are known to associate with nucleic acid (DNA) in non-covalent complexes via electrostatic interactions. Although their transfection efficiency has been proved, PAMAMs present a significant cytotoxicity due to their cationic surface. To overcome such a drawback, different chemical modifications of the PAMAM surface have been reported such as the attachment of hydrophobic residues. In the present work, we studied the complexation of DNA duplexes with different low-generation PAMAM; ammonia-cored G0(N) and G1(N) PAMAM, native or chemically modified with aromatic residues, i.e., phenyl-modified-PAMAM G0(N) and phenylalanine-modified-PAMAM G1(N). To investigate the interactions involved in the PAMAM/DNA complexes, also called dendriplexes, we used electrospray ionization (ESI) coupled to ion mobility spectrometry-mass-spectrometry (IM-MS). ESI is known to allow the study of non-covalent complexes in native conditions while IM-MS is a bidimensional separation technique particularly useful for the characterization of complex mixtures. IM-MS allows the separation of the expected complexes, possible additional non-specific complexes and the free ligands. Tandem mass spectrometry (MS/MS) was also used for the structural characterization. This work highlights the contribution of IM-MS and MS/MS for the study of small dendriplexes. The stoichiometries of the complexes and the equilibrium dissociation constants were determined. The [DNA/native PAMAM] and [DNA/modified-PAMAM] dendriplexes were compared.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Chemical structures of phenyl-modified-PAMAM (generation 0) (A) and phenylalanine-modified-PAMAM (generation 1) [PhenG1(N); n = 3] (B).
Figure 2
Figure 2
Negative-ion ESI mass spectrum (A) and IM-MS plot (drift time versus m/z) (B) of DNA duplex solution.
Figure 3
Figure 3
Negative-ion ESI mass spectra of [ds/G0(N)] (A) and [ds/φ3G0(N)] (B) dendriplexes solutions in 1:1 molar ratio.
Figure 4
Figure 4
Negative-ion ESI mass spectra of [ds/G0(N)] dendriplex (A) and [ds/φ3G0(N)] dendriplex (B) in 1:10 molar ratio solution.
Figure 5
Figure 5
Negative-ion ESI IM-MS plot (drift time vs. m/z) of [ds/φ3G0(N)] dendriplex in 1:10 molar ratio solution.
Figure 6
Figure 6
Negative-ion ESI MS/MS spectra of [ds/G0(N)-5H]5− (m/z 1529.7) (A) and [ds-5H]5− (m/z 1457.5) (B).
Figure 7
Figure 7
Negative-ion ESI-MS/MS spectra of [ds/φ3G0(N)-5H]5− (m/z 1610.5) (A) and [ds-5H]5− (m/z 1,457.5) (B).
Figure 8
Figure 8
Negative-ion ESI mass spectra of [ds/G1(N)] (A) and [ds/PhenG1(N)] (B) dendriplexes in 1:10 molar ratio solution. Insert: enlargement of m/z 1660–1763 range (dendriplexes ions region).
Figure 9
Figure 9
Negative-ion ESI IM-MS plot (drift time vs. m/z) of [ds/PhenG1(N)] dendriplex in 1:10 molar ratio solution.
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References

    1. Esfand R., Tomalia D.A. Poly(amidoamine) (PAMAM) dendrimers: from biomimicry to drug delivery and biomedical applications. Drug Discov. Today. 2001;6:427–436. - PubMed
    1. Eichman J., Bielinska A., Kukowska-Latallo J., Baker J. The use of PAMAM dendrimers in the efficient transfer of genetic material into cells. Pharm. Sci. Technol. Today. 2000;3:232–245. - PubMed
    1. Fischer D., Li Y., Ahlemeyer B., Krieglstein J., Kissel T. In vitro cytotoxicity testing of polycations: Influence of polymer structure on cell viability and hemolysis. Biomaterials. 2003;24:1121–1131. - PubMed
    1. Jevprasesphant R., Penny J., Jalal R., Attwood D., McKeown N.B., D’Emanuele A. The influence of surface modification on the cytotoxicity of PAMAM dendrimers. Int. J. Pharm. 2003;252:263–266. - PubMed
    1. Luo D., Haverstick K., Belcheva N., Han E., Saltzman W.M. Poly(ethylene glycol )-Conjugated PAMAM Dendrimer for Biocompatible, High-Efficiency DNA Delivery. Macromolecules. 2002;35:3456–3462.

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