Structural characterization of IgG1 mAb aggregates and particles generated under various stress conditions.
IgG1 mAb solutions were prepared with and without sodium chloride and subjected to different environmental stresses. Formation of aggregates and particles of varying size was monitored by a combination of size-exclusion chromatography, Nanoparticle Tracking Analysis, Micro-flow Imaging (MFI), turbidity, and visual assessments. Stirring and heating induced the highest concentration of particles. In general, the presence of NaCl enhanced this effect. The morphology of the particles formed from mAb samples exposed to different stresses was analyzed from transmission electron microscopy and MFI images. Shaking samples without NaCl generated the most fibrillar particles, whereas stirring created largely spherical particles. The composition of the particles was evaluated for covalent cross-linking by SDS-PAGE, overall secondary structure by FTIR microscopy, and surface apolarity by extrinsic fluorescence spectroscopy. Freeze-thaw and shaking led to particles containing protein with native-like secondary structure. Heating and stirring produced IgG1-containing aggregates and particles with some non-native disulfide cross-links, varying levels of intermolecular beta sheet content, and increased surface hydrophobicity. These results highlight the importance of evaluating protein particle morphology and composition, in addition to particle number and size distributions, to better understand the effect of solution conditions and environmental stresses on the formation of protein particles in mAb solutions.
Department of Pharmaceutical Chemistry, Macromolecule and Vaccine Stabilization Center, University of Kansas, Lawrence, Kansas, 66047.
Srivalli N
SN
Telikepalli
Ozan S
OS
Kumru
Cavan
C
Kalonia
Reza
R
Esfandiary
Sangeeta B
SB
Joshi
C Russell
CR
Middaugh
David B
DB
Volkin
D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D055598:Chemical Phenomena; D003080:Cold Temperature / Q000009:adverse effects; D003432:Cross-Linking Reagents / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007074:Immunoglobulin G / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D010316:Particle Size; D011489:Protein Denaturation; D055550:Protein Stability; D017433:Protein Structure, Secondary; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D005079:Excipients; D007074:Immunoglobulin G; D012965:Sodium Chloride
IgG; accelerated stability; formulation; monoclonal antibody; particle sizing; particles; protein; protein aggregation; stability