2 research outputs found
Biogenic and Synthetic Polyamines Bind Cationic Dendrimers
Biogenic polyamines are essential for cell growth and differentiation, while polyamine analogues exert antitumor activity in multiple experimental model systems, including breast and lung cancer. Dendrimers are widely used for drug delivery in vitro and in vivo. We report the bindings of biogenic polyamines, spermine (spm), and spermidine (spmd), and their synthetic analogues, 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333) to dendrimers of different compositions, mPEG-PAMAM (G3), mPEG-PAMAM (G4) and PAMAM (G4). FTIR and UV-visible spectroscopic methods as well as molecular modeling were used to analyze polyamine binding mode, the binding constant and the effects of polyamine complexation on dendrimer stability and conformation. Structural analysis showed that polyamines bound dendrimers through both hydrophobic and hydrophilic contacts with overall binding constants of Kspm-mPEG-G3β=β7.6Γ104 Mβ1, Kspm-mPEG-PAMAM-G4β=β4.6Γ104 Mβ1, Kspm-PAMAM-G4β=β6.6Γ104 Mβ1, Kspmd-mPEG-G3β=β1.0Γ105 Mβ1, Kspmd-mPEG-PAMAM-G4β=β5.5Γ104 Mβ1, Kspmd-PAMAM-G4β=β9.2Γ104 Mβ1, KBE-333-mPEG-G3β=β4.2Γ104 Mβ1, KBe-333-mPEG-PAMAM-G4β=β3.2Γ104 Mβ1, KBE-333-PAMAM-G4β=β3.6Γ104 Mβ1, KBE-3333-mPEG-G3β=β2.2Γ104 Mβ1, KBe-3333-mPEG-PAMAM-G4β=β2.4Γ104 Mβ1, KBE-3333-PAMAM-G4β=β2.3Γ104 Mβ1. Biogenic polyamines showed stronger affinity toward dendrimers than those of synthetic polyamines, while weaker interaction was observed as polyamine cationic charges increased. The free binding energies calculated from docking studies were: β3.2 (spermine), β3.5 (spermidine) and β3.03 (BE-3333) kcal/mol, with the following order of binding affinity: spermidine-PAMAM-G-4>spermine-PAMMAM-G4>BE-3333-PAMAM-G4 consistent with spectroscopic data. Our results suggest that dendrimers can act as carrier vehicles for delivering antitumor polyamine analogues to target tissues