Relating Collective Diffusion, Protein–Protein Interactions, and Viscosity of Highly Concentrated Monoclonal Antibodies through Dynamic Light Scattering

Abstract

To understand and predict the viscosities of highly concentrated monoclonal antibody (mAb) solutions, it is important to characterize the protein–protein interactions (PPI) and how they influence the possible formation of protein clusters. Herein, the collective diffusion is measured by dynamic light scattering (DLS) for solutions of three different mAbs, each with various cosolutes to tune the PPI. The results are combined with measurements of static structure factor, S(0), and self-diffusion coefficient, D s , to understand the behavior of viscosity at high concentration. The small degree of variation in the hydrodynamic factor, H(0), and solvent protein friction, f sp c s , among systems with a wide range of viscosities suggests solvent–protein interactions have a small influence on viscosity. Measurements of net PPI such as S(0) and the diffusion interaction parameter, k D , are predictive of high concentration viscosity across cosolutes for a single mAb, but not for multiple mAbs. In contrast, properties that characterize the presence of clusters in solution, such as the polydispersity index from DLS, PDI, and the coefficient of protein–protein friction, f pp c p , exhibit stronger correlations to viscosity.

Utility of High Resolution 2D NMR Fingerprinting in Assessing Viscosity of Therapeutic Monoclonal Antibodies

“…larger clusters, as have been detected for high concentration monoclonal antibody solutions (9,12) (9,12). In other cases, formation of long lived "dynamic clusters" that may result in increasing solution viscosities (55). While the underlying mechanism(s) of viscosity behavior at a molecular level remains elusive, several biophysical techniques have been used to study PPI.…”

Cluster Percolation Causes Shear Thinning Behavior in Concentrated Solutions of Monoclonal Antibodies

“…Due to the high solution concentrations often required, the average distance between protein molecules in biopharmaceutical products is comparable to the molecule size, , so that short-range, attractive protein–protein interactions (PPIs) become relevant, leading to a decrease of the long-term self-diffusion coefficient D S L . , Since D S L is related to the zero-shear viscosity η 0 by the Generalized Stokes–Einstein relationship (η 0 /η buffer = D 0 / D S L , where D 0 and η buffer are the diffusion coefficient in the limit of low protein concentration and the buffer viscosity, respectively; see ref ), values of η 0 as large as 0.1 Pa·s or above can be observed. − , On the other hand, the acceptable injection flow rates are typically on the order of 1 mL/10 s, which leads to characteristic rates of deformation equal to 10 4 –10 5 s –1 (calculated in this example for flows through 27G regular wall needles with an inner diameter of 290 μm). In addition, several other unit operations such as chromatography, vial filling by piston pumps, tangential flow filtration, and pumping through sterilized tubing are characterized by rates of deformations between 10 3 and 10 5 s –1 .…”

Why Should Tryptones Rather Than Bovine Serum Albumin Be Used as Model Proteins to Explore the Interactions between Proteins and Pollutants in Environments?

“…Ultraviolet visible (UV–vis) absorption spectra of the samples were tested with a 1 cm quartz cell, and the data were recorded on a UV–vis spectrophotometer (UV2450, Shimadzu Co.) with a range of 200–600 nm. The hydrodynamic diameter distribution and the ζ potentials of the samples were determined by dynamic light scattering (Zetasizer Nano ZS, Malvern Co.) with specific protein-related parameters, which are widely adopted for protein-like sample measurement. − The solid samples of BSA, three tryptones, and three solid environmental protein-like substances after being freeze-dried were collected and then formed into tablets with KBr, followed by Fourier transform infrared (FTIR) spectral measurement in transition mode on a spectrometer (Vertex 70, Bruker Co.). The morphological structures of the samples were characterized via scanning electron microscopy (SEM) (PW-100-51, Phenom Co.) and transmission electron microscopy (TEM) (TECNAI G2 Spirit BioTWIN, FEI Co.).…”