title: Quantitative measurement of Toll-like receptor 4 agonists adsorbed to Alhydrogel(®) by Fourier transform infrared-attenuated total reflectance spectroscopy.
abstract: Aluminum salts have a long history as safe and effective vaccine adjuvants. In addition, aluminum salts have high adsorptive capacities for vaccine antigens and adjuvant molecules, for example, Toll-like receptor 4 (TLR4) agonists. However, the physicochemical properties of aluminum salts make direct quantitation of adsorbed molecules challenging. Typical methods for quantifying adsorbed molecules require advanced instrumentation, extreme sample processing, often destroy the sample, or rely on an indirect measurement. A simple, direct, and quantitative method for analysis of adsorbed adjuvant molecules is needed. This report presents a method utilizing Fourier transform infrared spectroscopy with a ZnSe-attenuated total reflectance attachment to directly measure low levels (<30 μg/mL) of TLR4 agonists adsorbed on aluminum salts with minimal sample preparation.
authors.affiliation: Infectious Disease Research Institute, Seattle, Washington, 98102.
authors.forename: Quinton M
authors.initials: QM
authors.lastname: Dowling
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Schwartz
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Vedvick
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Fox
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Kramer
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000032:analysis* / Q000378:metabolism; D005960:Glucosides / Q000032:analysis* / Q000378:metabolism; D008050:Lipid A / Q000032:analysis* / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D051197:Toll-Like Receptor 4 / Q000819:agonists*
chemical_list: D005960:Glucosides; D008050:Lipid A; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; C000608161:glucopyranosyl lipid-A; D000536:Aluminum Hydroxide
keywords: Absorption Spectroscopy; FTIR; adsorption; aluminum hydroxide adjuvant; glucopyranosyl lipid adjuvant (GLA); hydrogels; vaccine adjuvants; vaccines