Scaling analytical RP-HPLC to semi-preparative for fractionation and characterization of pegfilgrastim oxidized variants.

Pegfilgrastim, a 40 kDa PEGylated form of recombinant human granulocyte colony-stimulating factor (rhG-CSF), is a biotherapeutic protein used to treat chemotherapy-induced neutropenia. To ensure the product is safe and effective, stringent monitoring of product-related impurities, particularly those arising from oxidative degradation, is necessary. This study focuses on the isolation and characterization of oxidized variants in pegfilgrastim using a multi-step approach that includes method transfer to semi-preparative High-Performance Liquid Chromatography (HPLC), mass spectrometry, and an in vitro cell-based potency assay (CBPA).

Immunological memory diversity in the human upper airway.

The upper airway is an important site of infection, but immune memory in the human upper airway is poorly understood, with implications for COVID-19 and many other human diseases. Here we demonstrate that nasal and nasopharyngeal swabs can be used to obtain insights into these challenging problems, and define distinct immune cell populations, including antigen-specific memory B cells and T cells, in two adjacent anatomical sites in the upper airway. Upper airway immune cell populations seemed stable over time in healthy adults undergoing monthly swabs for more than 1 year, and prominent tissue resident memory T (T) cell and B (B) cell populations were defined.

IBAT inhibitors in pediatric cholestatic liver diseases: Transformation on the horizon?

Historically, the therapeutic options available to hepatologists managing cholestasis have been limited. Apart from bile acid--binding resins and the choleretic ursodeoxycholic acid, the medical management of cholestasis in children has been predominately focused on managing the complications of cholestasis, namely pruritus, malnutrition, fat-soluble vitamin deficiencies, and portal hypertension. As such, invasive surgical procedures such as biliary diversion and liver transplantation may become the only options for progressive and unremitting cases of cholestasis.

Analysis of therapeutic monoclonal antibodies by imaged capillary isoelectric focusing (icIEF).

Imaged capillary isoelectric focusing (icIEF) is a preferred analytical method for determining isoelectric points (pIs) and charge heterogeneity profiles in biotherapeutic proteins. In this study, we optimized the icIEF method for an in-house IgG1κ monoclonal antibody (mAb-1) and assessed its reproducibility, robustness, and autosampler stability. The optimized method was used to evaluate batch-to-batch consistency in pIs for multiple lots of mAb-1 and determine the relative percentages of charge variants.