Abstract
To take a comprehensive evaluation of the bio-safety of doxorubicin-loaded superparamagnetic iron oxide nanoparticles (SPION), the interaction of bovine serum albumin (BSA) with the drug delivery was investigated by multi-spectroscopic techniques and molecular modelling calculation. Ultraviolet absorption and synchronous fluorescence results elucidate that DOX-SPION unfold the framework conformation of BSA, leading to changes in the microenvironment of amide moieties. Circular dichroism (CD) data show that the content of α-helix decreases from 68.62% to 62.76%, which shows the changes of protein's secondary structure quantificationally. Through Stern–Volmer analysis, the quenching mode is determined to be static interaction, forming a stable bioconjugate. The molecular model illustrates that DOX prefers a highly polar binding site at the external region of domains □ of BSA, and the hydrogen bonds are marked. This work elucidates that the drug delivery has deleterious effects on the frame conformation of protein, affecting its physiological function.
Acknowledgements
The authors thank technical support from the department of chemistry and Institute of Crystal Materials Shandong University.