Protein particles: what we know and what we do not know

Area of Science:

• Biopharmaceutical analysis
• Protein aggregation studies
• Immunogenicity research

Background:

• Therapeutic protein products inherently contain particles from protein monomer aggregation.
• Advancements in particle analysis and concerns about product quality/safety drive interest in understanding these particles.
• Current methods offer rudimentary particle counting, sizing, and characterization across a wide size range.

Purpose of the Study:

• To review known attributes of common protein particles in biopharmaceuticals.
• To discuss current knowledge gaps in particle characterization.
• To identify limitations and opportunities for improving particle analysis methods.

Main Methods:

• Literature review of protein particle attributes.
• Analysis of capabilities and limitations of current particle characterization techniques.
• Discussion of knowledge gaps regarding particle diversity and immunogenicity.

Main Results:

• Common protein particles exhibit variations in unfolding, nucleation centers, and morphology.
• Existing methods provide basic characterization but lack detailed classification capabilities.
• Significant gaps exist in understanding the correlation between particle attributes and immunogenicity.

Conclusions:

• Enhanced analytical methods are crucial for detailed classification and characterization of protein particles.
• Further research is essential to elucidate the relationship between specific particle attributes and potential immunogenicity.
• Addressing these knowledge gaps is vital for ensuring the safety and efficacy of therapeutic protein products.