Application of a Best Practice Approach Using Resonant Mass Measurement for Biotherapeutic Product Characterization.

Characterizing and quantifying subvisible particles in protein drug products is critical to ensuring product quality. A variety of analytical methods are used to detect and make meaningful measurements of subvisible particles. Resonant mass measurement (RMM) is a novel technology that characterizes the subvisible particle content of samples on a particle-by-particle basis.

UV photodegradation of murine growth hormone: chemical analysis and immunogenicity consequences.

During manufacturing, therapeutic proteins may be exposed to ultraviolet (UV) radiation. Such exposure is of concern because UV radiation may cause photooxidative damage to proteins, which in turn could lead to physical changes such as aggregation and enhanced immunogenicity. We exposed murine growth hormone (mGH) to controlled doses of UV radiation, and examined the resulting chemical, physical and immunogenic changes in the protein.

Glass particles as an adjuvant: a model for adverse immunogenicity of therapeutic proteins.

Unwanted immune responses to parenterally administered therapeutic proteins pose serious safety and economic risks, but the mechanism(s) by which these responses are generated are unknown. We measured immune responses to aggregates of recombinant murine growth hormone (mGH) formed by agitation or freeze-thawing, two pharmaceutically relevant stresses, as well as to mGH adsorbed on microscopic glass or alum particles. Insoluble aggregates, even at levels below the detection limits of size-exclusion high-performance liquid chromatography analysis (<1%), induce immune responses when administered subcutaneously.

Recombinant murine growth hormone from E. coli inclusion bodies: expression, high-pressure solubilization and refolding, and characterization of activity and structure.

We expressed recombinant murine growth hormone (rmGH) in E. coli as a cost-effective way to produce large quantities (gram scale) of the protein for use in murine studies of immunogenicity to therapeutic proteins. High hydrostatic pressure was used to achieve high solubility and high refolding yields of rmGH protein produced in E.

Immunogenicity of aggregates of recombinant human growth hormone in mouse models.

Aggregation of recombinant therapeutic protein products is a concern due to their potential to induce immune responses. We examined the immunogenicity of protein aggregates in commercial formulations of recombinant human growth hormone produced by freeze-thawing or agitation, two stresses commonly encountered during manufacturing, shipping and handling of therapeutic protein products. In addition, we subjected each preparation to high-pressure treatment to reduce the size and concentration of aggregates present in the samples.