Physiochemical Changes to TTCF Ensilication Investigated Using Time-Resolved SAXS (2021) |
Aswin Doekhie 1,*, Rajeev Dattani 2, Yun-Chu Chen 1, Francoise Koumanov 3, Karen J. Edler 1, Jean M. H. van den Elsen 4 and Asel Sartbaeva1
1 Department of Chemistry, University of Bath, Bath BA2 7AY, UK
2 European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS 40220, CEDEX 09, 38043 Grenoble, France
3 Department for Health, University of Bath, Bath BA2 7AY, UK
4 Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK
*Author to whom correspondence should be addressed.
Abstract
Successful eradication or control of prevailing infectious diseases is linked to vaccine efficacy, stability, and distribution. The majority of protein-based vaccines are transported at fridge (2–8 °C) temperatures, cold chain, to retain potency. However, this has been shown to be problematic. Proteins are inherently susceptible to thermal fluctuations, occurring during transportation, causing them to denature. This leads to ineffective vaccines and an increase in vaccine-preventable diseases, especially in low-income countries. Our research utilises silica to preserve vaccines at room temperature, removing the need for cold chain logistics. The methodology is based upon sol–gel chemistry in which soluble silica is employed to encapsulate and ensilicate vaccine proteins. This yields a protein-loaded silica nanoparticle powder which is stored at room temperature and subsequently released using a fast chemical process. We have previously shown that tetanus toxin C fragment (TTCF) ensilication is a diffusion-limited cluster aggregation (DLCA)-based process using time-resolved small-angle x-ray scattering (SAXS). Here, we present our expanded investigation on the modularity of this system to further the understanding of ensilication via time-resolved SAXS. Our results show that variations in the ensilication process could prove useful in the transition from batch to in-flow manufacturing of ensilicated nanoparticles.