The synthesis of hydroxyethyl starch 200/0.5-loaded albumin nanoparticles: biocompatibility and interaction mechanism

We aim to synthesize hydroxyethyl starch (HES) 200/0.5 -loaded bovine serum albumin nanoparticles (HBNs) and investigate the compatibility and binding mechanism in simulated physiological environments. Herein, to elucidate the morphology, biocompatibility, and formation mechanism of HBNs, techniques such as scanning electron microscopy, hemolysis test, fluorescence, and circular dichroism spectroscopy were applied. The thermodynamic parameters at body temperature (Δ G =-2.35×10 4 J·mol − 1 , Δ S °=-26.7 J·mol − 1 ·K − 1 , and Δ H °=-3.20×10 4 J·mol − 1 ) showed a 1:1 binding stoichiometry, which was governed by hydrogen bonds and van der Waals interactions. Moreover, the conformational analysis revealed that the microenvironment of fluorophores was changed with the adaptational protein secondary structural changes. Energy transfer occurred from the fluorophores to HES with a high possibility. All these results provided accurate and complete primary data for clarifying the binding mechanisms of HES with BSA, which helps understand its pharmaceutical effects in blood.