Interactions of polyglycerol dendrimers with human serum albumin: insights from fluorescence spectroscopy and computational modeling analysis.

Polyglycerol dendrimer synthesized from glycerol core (PGLyD) is an interesting reservoir macromolecule for the design of drug delivery systems due to their adequate blood biocompatibility. However, important features as the comprehension of the structural and dynamic characteristics and the interactions of PGLyD with blood proteins receptors remain unresolved. The high affinity and transport of HSA with drugs stimulated the docking simulations utilizing PGLyD as a ligand for the main HSA docking sites IIA and IIIA. HSA and the PGLyD structures were generated with the aid of Autodock Vina and the best conformations were determined by employing molecular docking. The molecular docking results indicate a thermodynamically favorable interaction suggesting a charge transfer complex formation between HSA and PGLyD. The interaction between PGLyD and HSA was investigated by fluorescence and the quenching mechanism of fluorescence of HSA by PGLyD was discussed. The binding constants and the number of binding sites were measured. The values of thermodynamic parameters ΔG, ΔH, and ΔS were calculated at three different temperatures. The experimental and computational results suggest that hydrophobic forces play a major role in stabilizing the HSA-PGLyD complex.