Dialysis Monitoring of Ionic Strength and Denaturant Effects, and Their Reversibility, for Various Classes of Macromolecules.

Monitoring membrane-mediated dialysis in real time with static and dynamic light scattering revealed distinctive differences, including reversibility/irreversibility, in the effects of ionic strength (NaCl) and the denaturant guanidine-HCl (Gd) on a synthetic polyelectrolyte and several types of biomacromolecules: protein, polysaccharide, and polyampholyte. Dialysis cycles against aqueous NaCl and Gd, and reverse back to the original aqueous solution, were monitored. The behavior of Na-polystyrenesulfonate was reversible and yielded a detailed polymer physics description.

DNA Released by Adeno-Associated Virus Strongly Alters Capsid Aggregation Kinetics in a Physiological Solution.

While adeno-associated virus is a leading vector for gene therapy, significant gaps remain in understanding AAV degradation and stability. In this work, we study the degradation of an engineered AAV serotype at physiological pH and ionic strength. Viral particles of varying fractions of encapsulated DNA were incubated between 30 and 60 °C, with changes in molecular weight measured by changes in total light scattering intensity at 90° over time.

Route and antigen shape immunity to dmLT-adjuvanted vaccines to a greater extent than biochemical stress or formulation excipients.

A key aspect to vaccine efficacy is formulation stability. Biochemical evaluations provide information on optimal compositions or thermal stability but are routinely validated by ex vivo analysis and not efficacy in animal models. Here we assessed formulations identified to improve or reduce stability of the mucosal adjuvant dmLT being investigated in polio and enterotoxigenic E.

A polarization sensitive light scattering unit for high throughput screening.

A simple, effective light scattering prototype sensitive to both polarized and depolarized scattering was constructed, and its performance was tested on a variety of pure liquids and optically isotropic and anisotropic polymer solutions and colloidal suspensions. The results, performance, and means to further improvement are reported here. Because of its simplicity and low cost, many identical units can be produced to construct a simultaneous multiple sample light scattering platform that can be used to monitor polymer and colloid solution stability, phase changes, aggregation, degradation, etc.

On the Reproducibility of Early-Stage Thermally Induced and Contact-Stir-Induced Protein Aggregation.

Is aggregation kinetics for a protein under given conditions reproducible? Is aggregation inherently deterministic, stochastic, or even chaotic? Because protein aggregation in ex vivo formulations is complex, with many origins and manifestations, the question of aggregation reproducibility for a given protein, formulation, and stressor is of both fundamental and practical significance. This work concerns temperature-induced and contact-stir-induced aggregation of bovine serum albumin (BSA) and a monoclonal antibody (mAbX). It assesses reproducibility via early-stage aggregation rates (ARs) from light scattering.

Diisocyanate emission from a paint product: a preliminary analysis.

Exposure of workers to diisocyanates in the polyurethane foam manufacturing industry is well documented. However, very little quantitative data have been published on exposure to diisocyanates from the use of paints and coatings. The purpose of this study was to evaluate emission of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate (2,6-TDI), and isophorone diisocyanate from a commercially available two-stage concrete coating and sealant.