Aggregate Removal Nanofiltration of Human Serum Albumin Solution Using Nanocellulose-Based Filter Paper

Area of Science:

• Biotechnology
• Bioprocessing
• Filtration Technology

Background:

• Plasma-derived human serum albumin (HSA) requires purification to remove protein aggregates and viruses, ensuring product safety.
• Current virus inactivation methods, such as heat treatment, can impact protein integrity.
• Developing efficient and safe virus removal techniques is crucial for biopharmaceutical production.

Purpose of the Study:

• To develop and evaluate a rapid two-step filtration process for removing protein aggregates and viruses from HSA.
• To assess the efficacy of nanocellulose filters with varying thicknesses for aggregate and virus clearance.
• To investigate the impact of transmembrane pressure on virus removal efficiency and product throughput.

Main Methods:

• A two-step filtration system using nanocellulose filters (11 μm prefilter, 22 μm virus filter) was employed.
• Nitrogen gas sorption analysis characterized filter pore size distribution.
• Dynamic light scattering (DLS) and size-exclusion high performance liquid chromatography (SE-HPLC) analyzed HSA aggregates.
• Model virus clearance was quantified using log10 reduction values (LRV) at different pressures.

Main Results:

• The 11 μm prefilter effectively removed HSA aggregates (40-60 nm pores), preventing fouling of the 22 μm virus filter.
• High model virus clearance (LRV > 5) was achieved at 3 and 5 bar, with reduced clearance at 1 bar.
• HSA throughput was pressure-dependent (Vmax 110 ± 2.5 L m⁻² at 3 bar, 63.6 ± 5.8 L m⁻² at 5 bar).
• Protein recovery exceeded 90% with minimal loss.

Conclusions:

• Nanocellulose filtration offers an effective method for simultaneous removal of protein aggregates and viruses from HSA.
• This nanofiltration approach enhances biosafety and provides a viable alternative to traditional virus inactivation methods.
• The study demonstrates the potential of tailored nanocellulose filters in bioprocessing for improved product safety and quality.