Insulin and Human Serum Albumin Interactions with Core-Shell Fe₃O₄@SiO₂ Nanoparticles Functionalized with Carboranes

Area of Science:

• Biomaterials Science
• Nanotechnology
• Protein Chemistry

Background:

• Nanoparticles (NPs) interact with proteins in biological media, altering protein structure and function.
• Understanding protein-nanoparticle interactions is crucial for medical applications of functional NPs.
• Boron neutron capture therapy (BNCT) utilizes targeted nanoparticles.

Purpose of the Study:

• To investigate the interactions between specific functional nanoparticles and human serum albumin (HSA) and insulin.
• To characterize the structural changes in proteins upon adsorption onto nanoparticles.
• To determine the binding affinity and nature of protein-nanoparticle interactions.

Main Methods:

• Spectrofluorometry
• Circular dichroism (CD) spectroscopy
• Isothermal titration calorimetry (ITC)

Main Results:

• Protein adsorption onto nanoparticles is an enthalpy-entropy-driven process, leading to significant structural changes.
• HSA experienced a substantial reduction in alpha-helix content (from 87.59% to 40.9%) and increased beta-sheet and random coil structures.
• Insulin showed weaker interaction with nanoparticles compared to HSA, with a 15% decrease in alpha-helix content.

Conclusions:

• The functional nanoparticles induce significant conformational changes in both HSA and insulin.
• HSA exhibits a stronger binding affinity to the nanoparticles than insulin.
• These findings provide insights into protein-nanoparticle interactions for targeted medical therapies like BNCT.