Understanding lipopolysaccharide aggregation and its influence on activation of Factor C.

The quantification of lipopolysaccharide (LPS) shed by bacteria within aqueous samples is typically performed by binding LPS to a protein called Factor C within a lysate prepared from the blood of horseshoe crabs (Limulus amebocyte lysate (LAL)). How the state of aggregation of LPS impacts Factor C activation, however, is not understood, particularly in the presence of select salts and non-ionic surfactants that are commonly incorporated into pharmaceutical formulations. To address this open question, herein we report on the aggregation status of LPS in aqueous solution, characterized using angle-dependent static and dynamic light scattering with and without chelating salts and polysorbate surfactants, and its correlation with activation of Factor C.

Mechanistic evaluation of virus clearance by depth filtration.

Virus clearance by depth filtration has not been well-understood mechanistically due to lack of quantitative data on filter charge characteristics and absence of systematic studies. It is generally believed that both electrostatic interactions and sized based mechanical entrapment contribute to virus clearance by depth filtration. In order to establish whether the effectiveness of virus clearance correlates with the charge characteristics of a given depth filter, a counter-ion displacement technique was employed to determine the ionic capacity for several depth filters.

A novel approach to achieving modular retrovirus clearance for a parvovirus filter.

Viral filtration is routinely incorporated into the downstream purification processes for the production of biologics produced in mammalian cell cultures (MCC) to remove potential viral contaminants. In recent years, the use of retentive filters designed for retaining parvovirus (~20 nm) has become an industry standard in a conscious effort to further improve product safety. Since retentive filters remove viruses primarily by the size exclusion mechanism, it is expected that filters designed for parvovirus removal can effectively clear larger viruses such as retroviruses (~100 nm).

Effectiveness of mouse minute virus inactivation by high temperature short time treatment technology: a statistical assessment.

Viral contamination of mammalian cell cultures in GMP manufacturing facility represents a serious safety threat to biopharmaceutical industry. Such adverse events usually require facility shutdown for cleaning/decontamination, and thus result in significant loss of production and/or delay of product development. High temperature short time (HTST) treatment of culture media has been considered as an effective method to protect GMP facilities from viral contaminations.

Root cause investigation of a viral contamination incident occurred during master cell bank (MCB) testing and characterization--a case study.

An adventitious agent contamination occurred during a routine 9 CFR bovine viral screening test at BioReliance for an Eli Lilly Chinese Hamster Ovary (CHO) cell-derived Master Cell Bank (MCB) intended for biological production. Scientists from the sponsor (Eli Lilly and Company) and the testing service company (BioReliance) jointly conducted a systematic investigation in an attempt to determine the root cause of the contamination. Our investigation resulted in the identification of the viral nature of the contaminant.