title: Physical characterization and in silico modeling of inulin polymer conformation during vaccine adjuvant particle formation.
abstract: This study combined physical data from synchrotron SAXS, FTIR and microscopy with in-silico molecular structure predictions and mathematical modeling to examine inulin adjuvant particle formation and structure. The results show that inulin polymer chains adopt swollen random coil in solution. As precipitation occurs from solution, interactions between the glucose end group of one chain and a fructose group of an adjacent chain help drive organized assembly, initially forming inulin ribbons with helical organization of the chains orthogonal to the long-axis of the ribbon. Subsequent aggregation of the ribbons results in the layered semicrystalline particles previously shown to act as potent vaccine adjuvants. γ-Inulin adjuvant particles consist of crystalline layers 8.5 nm thick comprising helically organized inulin chains orthogonal to the plane of the layer. These crystalline layers alternate with amorphous layers 2.4 nm thick, to give overall particle crystallinity of 78%.
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia. Electronic address: tom.barclay@unisa.edu.au.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Barclay
authors.affiliation: Vaxine Pty Ltd, Flinders Medical Centre, Bedford Park, SA 5042, Australia. Electronic address: harinda.rajapaksha@sa.gov.au.
authors.forename: Harinda
authors.initials: H
authors.lastname: Rajapaksha
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia. Electronic address: thilagam.lohe@unisa.edu.au.
authors.forename: Alagu
authors.initials: A
authors.lastname: Thilagam
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia. Electronic address: gujie.qian@unisa.edu.au.
authors.forename: Gujie
authors.initials: G
authors.lastname: Qian
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia. Electronic address: milena.ginic-markovic@unisa.edu.au.
authors.forename: Milena
authors.initials: M
authors.lastname: Ginic-Markovic
authors.affiliation: Vaxine Pty Ltd, Flinders Medical Centre, Bedford Park, SA 5042, Australia; Cancer Research Laboratory, ANU Medical School, Garran, ACT 2605, Australia; John Curtin School of Medical Research, ANU, Acton, ACT 2601, Australia. Electronic address: doddcoop@ozemail.com.au.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Cooper
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia; Blue Minerals Consultancy, Mill Terrace, Middleton, SA 5213, Australia. Electronic address: andrea.gerson@bigpond.au.
authors.forename: Andrea
authors.initials: A
authors.lastname: Gerson
authors.affiliation: Vaxine Pty Ltd, Flinders Medical Centre, Bedford Park, SA 5042, Australia; Department of Endocrinology, Flinders Medical Centre/Flinders University, Bedford Park, SA 5042, Australia. Electronic address: nikolai.petrovsky@flinders.edu.au.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Petrovsky
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry*; D002236:Carbohydrate Conformation; D003198:Computer Simulation; D007444:Inulin / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D056004:Molecular Dynamics Simulation; D053838:Scattering, Small Angle; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D000276:Adjuvants, Immunologic; D007444:Inulin
keywords: Adjuvant; FTIR; Inulin; Inulin from chicory (PubChem CID: 16219508); Modeling; Polysaccharide; SAXS