Measuring and Characterizing Protein Aggregates

Multiwavelength Transmission Spectroscopy Revisited for the Characterization of the Protein and Polystyrene Nanoparticle Mixtures

“…These complex macromolecules have colloidal behaviors that can considerably affect their therapeutic value, delivery systems, shelf life, and most importantly, patient safety. 1,–4 As a result, both the pharmaceutical industry and the regulatory agencies have taken a keen interest in analytical methods that can reliably characterize the properties of these macromolecules, their aggregates, and their associated drug-delivery systems. 1,–4 It should be noted that the term aggregates in the pharmaceutical industry refers to any self-associated nonnative species from dimers to visible particles 4 and therefore implies a very large range of sizes and types.…”

“…1,–4 As a result, both the pharmaceutical industry and the regulatory agencies have taken a keen interest in analytical methods that can reliably characterize the properties of these macromolecules, their aggregates, and their associated drug-delivery systems. 1,–4 It should be noted that the term aggregates in the pharmaceutical industry refers to any self-associated nonnative species from dimers to visible particles 4 and therefore implies a very large range of sizes and types. 1,2 The analytical chemistry and particle characterization industries have responded with improvements in standard characterization techniques such as multiangle and dynamic (DLS) light scattering, electrophoretic mobility, and particle counters and with improvements in the performance of fractionation-based methods such as size exclusion chromatography, field flow fractionation, and automatic ultracentrifugation.…”

“…Critical technology reviews have concluded that although fractionation techniques have been proven effective, they are also invasive to the sample, and there is always the question as to whether or not the fractionation processes alters the native state of the sample. 4,5 Also, because of the range of aggregate properties to be determined, several methods and instruments are usually required, particularly when both the distribution of particle sizes and particle types are desired. 6 The use of several methods based on different measurement principles and different sensitivities brings about issues related to different sample preparation requirements, data interpretation, and data reconciliation.…”

Multiwavelength Transmission Spectroscopy Revisited for the Characterization of the Protein and Polystyrene Nanoparticle Interactions

“…11 Further, sample fractionation when using size-exclusion chromatography, field-flow fractionation, or automatic ultracentrifugation is usually necessary to prepare a sample, but these fractionation methods are invasive to a sample and can alter its native state. 12,13 Overall, the need to combine several methods based on different measurement principles, different sensitivities, and different sample preparation requirements complicates data reconciliation.…”