Human serum albumin adsorption on cellulose nanocrystal: A spectroscopy and molecular dynamics simulation research

Abstract

Cellulose nanocrystal (CNC) is a relatively new natural nanoparticle derived from plants. Several biomedical applications are envisioned for CNC. Although its safety upon systemic administration is still questionable, it may serve as a worthy substrate for the adsorption of blood proteins in ex vivo settings for diagnostic purposes. The interaction between CNC and Human serum albumin (HSA) may influence both structure and function of other adsorbed proteins on the CNC surface. Herein, molecular dynamics (MD) simulation and circular dichroism spectroscopy (CD) were utilized to study the conformational changes of HSA in the presence and absence of the CNC. The secondary structure study results show that the HSA structure was conserved during the interaction. Fluorescence spectroscopy indicates that the CNC has a quenching property on the intrinsic fluorescence of HSA. Furthermore, increasing CNC concentrations led to a blue shift in the HSA fluorescence emission at 344 nm. The Gibbs free energy demonstrated the HSA and CNC interaction is spontaneous; the MMPBSA outcomes also approved that electrostatic and van der Waals (vdW) interactions were the major forces in the HSA-CNC complex. The results of this study shed light on the adsorption of HSA on CNC and the nature of their interactions.