Structural Instability of Human Serum Albumin during Microparticles Synthesis

Area of Science:

• Biomaterials Science
• Protein Engineering
• Nanotechnology

Background:

• Human serum albumin (HSA) is a versatile plasma protein with significant biomedical potential.
• Its properties like biocompatibility and binding affinity make it ideal for drug delivery systems.
• However, processing HSA into microparticles can alter its structure and function.

Purpose of the Study:

• To characterize human serum albumin microparticles (HSA-MPs) produced via a specific method.
• To investigate the structural changes and their impact on HSA's binding capabilities.
• To explore the implications for biomedical applications, particularly drug delivery.

Main Methods:

• Coprecipitation-cross-linking-dissolution method for HSA-MP synthesis.
• Physicochemical characterization including morphology and mechanical properties.
• Raman and FTIR spectroscopy to analyze protein secondary structure changes.
• Binding assays to assess HSA's interaction with ligands like hemin.

Main Results:

• Submicron HSA-MPs were produced with uniform, peanut-shaped morphology and robust mechanical properties.
• Microparticle formation induced structural changes, shifting HSA from α-helices to β-sheets.
• This structural alteration led to diminished binding capability for ligands such as hemin.
• Reduced surface binding prevents unintended ligand transport, offering a potential safety mechanism.

Conclusions:

• HSA-MPs exhibit a trade-off between mechanical strength and native protein binding activity.
• Structural changes impact HSA's utility in applications requiring precise molecular interactions.
• The findings suggest strategies for engineering HSA-MPs with tailored properties for specific biomedical uses.
• HSA-MPs could be engineered to balance structural resilience with controlled functional surface activity.