Serum albumins have five sites for binding of cationic dendrimers.

The detailed analysis of the interaction between PAMAM G4 dendrimer and serum albumins was performed using circular dichroism, isothermal titration calorimetry, capillary electrophoresis, zeta-potential and fluorescence polarization. It was shown that serum albumins and PAMAM G4 dendrimer form the complex with stoichiometry of 4-6:1 for G4:HSA and 4-5:1 for G4:BSA molar ratio. The possible sites of PAMAM G4 dendrimers binding to protein surface were discussed. Also, it has been proposed that dendrimer does not significantly affect the protein secondary structure studied by circular dichroism.

Impact of PAMAM G2 and G6 dendrimers on bovine serum albumin (fatty acids free and loaded with different fatty acids).

Dendrimers are a new class of nanotechnological polymers suitable for drug targeting, microarray systems or detoxication. The present study is devoted to a detailed analysis of binding between PAMAM dendrimers and bovine serum albumin (fatty acid free or loaded with oleic, linoleic, oleic+linoleic or oleic+linoleic+arachodonic acids) by measuring zeta-potential, fluorescence quenching, fluorescence anisotropy and electron paramagnetic resonance. Addition of PAMAM G2 and G6 dendrimers to protein solutions resulted in attachment to the protein molecule. The PAMAM dendrimers also competed with BSA for fatty acids if two or three fatty acids were loaded per protein. This can lead to the extraction of fatty acids from BSA to the PAMAM dendrimer.

Interaction between PAMAM 4.5 dendrimer, cadmium and bovine serum albumin: a study using equilibrium dialysis, isothermal titration calorimetry, zeta-potential and fluorescence.

Binding of Cd(2+) by PAMAM 4.5 dendrimer was studied by equilibrium dialysis, isothermal titration calorimetry and zeta-potential measurement. The following binding parameters were obtained: n=23.8+/-9.5, K(b)=4.7+/-0.9x10(3) in water; and n=41.3+/-13.4, K(b)=2.1+/-0.8x10(3) in 0.15 mol/l phosphate-buffered saline. The location of the bound Cd(2+) is discussed. The interactions between bovine serum albumin, PAMAM 4.5 dendrimer and cadmium were analyzed using fluorescence and equilibrium dialysis. The competition between Cd(2+) binding to BSA and PAMAM 4.5 dendrimer was investigated. It is proposed that PAMAM 4.5 dendrimer could be successfully used for extracting Cd(2+) from aqueous solutions (environmental protection).

Surface properties of zinc oxide nanoparticles studied by inverse gas chromatography.

Inverse gas chromatography (IGC) was applied in infinite dilution to evaluate the surface properties of zinc oxide nanoparticles with respect to their specific surface area, particle size and morphology (spherical, whiskers, and snowflakes). The dispersive components (gamma(S)(D)) of the free energy of zinc oxides were determined by Gray's method, whereas their tendency to undergo specific interactions was estimated based on the electron donor-acceptor approach presented by Papirer. The zinc oxide nanoparticles exhibited high surface energies that were dependent on their morphology. The highest value of gamma(S)(D) was determined for spherical zinc oxide particles with high specific surface area, which had the most structure defects. The specific interactions were characterized by the energy (DeltaG(A)(SP)) and enthalpy (DeltaH(A)(SP)) of adsorption as well as the donor and acceptor interaction parameters (K(A), K(D)).

The interaction between PAMAM G3.5 dendrimer, Cd2+, dendrimer-Cd2+ complexes and human serum albumin.

The interactions between PAMAM G3.5 dendrimer, Cd2+, a complex of "PAMAM G3.5 dendrimer-Cd2+" and human serum albumin were studied by equilibrium dialysis, fluorescence quenching, fluorescence anisotropy and zeta-potential. It was found that in water one molecule of PAMAM 3.5 dendrimer can bind 38+/-9 cadmium ions with Kb=1.3+/-0.13 x 10(3). The calculated Stern-Volmer constants of albumin fluorescence quenching by Cd2+, G3.5 and the "PAMAM G3.5-Cd2+" complex were 2.2+/-0.2, 1.6+/-0.3 and 1.4+/-0.1(mmol/l)(-1), respectively. The data from the fluorescence and zeta-potential studies show that the "PAMAM G3.5-Cd2+" complex interacted much less strongly with human serum albumin than the pure dendrimer or Cd2+.