Application of Extrinsic Fluorescence Spectroscopy for the High Throughput Formulation Screening of Aluminum-Adjuvanted Vaccines

Mechanism of Immunopotentiation and Safety of Aluminum Adjuvants

“…This likely contributes to reduced desorption of antigens from aluminum adjuvants in aged vaccines (Shi et al, 2001a; Vessely et al, 2009). Several biophysical assays including differential scanning calorimetry, intrinsic (tryptophan) and extrinsic fluorescence, and Fourier transform infrared spectroscopy, have been successfully employed in recent years to assess the conformational stability of proteins adsorbed onto aluminum adjuvants (Jones et al, 2005; Peek et al, 2007; Ausar et al, 2011; Iyer et al, 2012; Ljutic et al, 2012). Adsorption usually decreases the stability of proteins, but increased stability of AH-adsorbed proteins was observed in a few cases (Estey et al, 2009; Iyer et al, 2012).…”

High-Throughput Screening of Excipients Intended to Prevent Antigen Aggregation at Air-Liquid Interface

“…HTS technologies have been used in developing stable formulations of monoclonal antibodies (25), therapeutic proteins (26), and vaccines (27). However, sensitivity issues may make some HTS analytical methods incompatible with the low antigen concentrations found in vaccines.…”

Pharmaceutical Analysis and Quality Control of Vaccines

“…It is clear that immunogenicity is impacted by antigen adsorption to the adjuvant, but we are still far away from understanding the factors that make an antigen more immunogenic as systematic studies that compare antigen adsorption capacity, adsorption coeffi cient, desorption potential, and stability in relationship to immune response are only a handful. An interesting study in this regard has recently been published where, for the fi rst time, the authors attempt a systematic study of these different parameters and substantiate the hypothesis present in the literature that a strong interaction between the antigen and the adjuvant may hamper processing of the antigens by the immune system resulting in a lower immune response and suggest the importance of studying the antigen-adjuvant adsorption (Ausar et al 2011 ). From this question, which is probably the central one, more questions arise on how to understand and control adsorption maturation and the impact on the immune response: This question could be very important to connect formulation maturation to immunogenicity and one day may have the potential to impact how we will determine the shelf-life of a product.…”

“…However, none of these, with the exception of the antibody-based techniques and NMR, has the level of detail required for an in-depth structural characterization of the changes occurring. More generally, all these techniques can be used to describe average changes like rearrangements of elements of secondary Theoretically possible but not tested structure, stability of thermal domains, or changes in exposure of aromatic or hydrophobic residues as a consequence of the measurement conditions employed (Jones et al 2005 ;Ausar et al 2011 ). Currently, by taking advantage of these techniques we understand that both the adjuvant and the antigen(s) change as a matter of their reciprocal interaction.…”