The role of mesoporous silica morphology in the incorporation of diphtheria and tetanus anatoxins: potential adjuvants for oral vaccines

• Grant number: 20/13204-7
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): February 01, 2021
• Effective date (End): January 31, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal researcher: Marcia Carvalho de Abreu Fantini
• Grantee: Pedro Leonidas Oseliero Filho
• Supervisor abroad: Heloisa Nunes Bordallo
• Home Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: University of Copenhagen, Denmark
• Associated to the scholarship: 19/12301-1 - Synthesis of ordered mesoporous silica with different structures and morphologies, BP.PD

Abstract

We propose the synthesis and characterization of ordered mesoporous silica (OMS) with new morphology as functional adjuvants for tetanus and diphtheria oral vaccines. For this study, our focus will rely on two mesoporous materials: SBA-15 and FDU-12. In addition to the regular synthesis, we will modify the reaction and hydrothermal treatment temperature, agitation and include a swelling agent (in the case of SBA-15) in order to obtain materials with different textural properties (e.g., particle size, superficial area, pore size, volume and ordering). Once the materials are synthetized, we will incorporate tetanus and diphtheria anatoxins (used to vaccine manufacturing) into the OMS following a protocol stablished by Prof. Fantini's group. As shown by Rasmussen et al. in a recent investigation, the textural properties of OMS play a fundamental role in the incorporation of anatoxins and, consequently, in the adjuvant effect of the complex OMS + anatoxin. Therefore, we will apply several techniques to characterize both the anatoxins, OMS and the complexes. Nitrogen Adsorption Isotherm (NAI) and Small-angle X-ray Scattering (SAXS) will be used to probe structural and morphology aspects of OMS (SAXS will also be used to characterized the anatoxins in solution) whereas Raman Imaging (RI) and Thermal Analysis (including Thermogravimetry (TG), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC)) will be employed i) to confirm that anatoxins are somehow incorporated in OMS, ii) to quantify the mass of incorporated anatoxin and finally iii) to provide a chemical map of the anatoxins' distribution in the OMS structure. The combination of these techniques will allow us to correlate the physicochemical mechanisms involved in the formation of the complexes OMS + anatoxin whose comprehension is the first step to the development of potential adjuvants for oral vaccines. (AU)