B21-High Throughput SAXS
|
Open Access
Abstract: The current SARS-Covid-2 (SARS-CoV-2) pandemic has led to an acceleration of messenger ribonucleic acid (mRNA) vaccine technology. The development of production processes for these large mRNA molecules, especially self-amplifying mRNA (saRNA), has required concomitant development of analytical characterization techniques. Characterizing the purity, shape and structure of these biomolecules is key to their successful performance as drug products. This article describes the biophysical characterization of the Imperial College London Self-amplifying viral RNA vaccine (IMP-1) developed for SARS-CoV-2. A variety of analytical techniques have been used to characterize the IMP-1 RNA molecule. In this article, we use ultraviolet spectroscopy, dynamic light scattering, size-exclusion chromatography small-angle X-ray scattering and circular dichroism to determine key biophysical attributes of IMP-1. Each technique provides important information about the concentration, size, shape, structure and purity of the molecule.
|
Jan 2023
|
|
|
|
Jill
Trewhella
,
Patrice
Vachette
,
Jan
Bierma
,
Clement
Blanchet
,
Emre
Brookes
,
Srinivas
Chakravarthy
,
Leonie
Chatzimagas
,
Thomas E.
Cleveland
,
Nathan
Cowieson
,
Ben
Crossett
,
Anthony P.
Duff
,
Daniel
Franke
,
Frank
Gabel
,
Richard E.
Gillilan
,
Melissa
Graewert
,
Alexander
Grishaev
,
J. Mitchell
Guss
,
Michal
Hammel
,
Jesse
Hopkins
,
Qingqui
Huang
,
Jochen S.
Hub
,
Greg L.
Hura
,
Thomas C.
Irving
,
Cy Michael
Jeffries
,
Cheol
Jeong
,
Nigel
Kirby
,
Susan
Krueger
,
Anne
Martel
,
Tsutomu
Matsui
,
Na
Li
,
Javier
Pérez
,
Lionel
Porcar
,
Thierry
Prange
,
Ivan
Rajkovic
,
Mattia
Rocco
,
Daniel J.
Rosenberg
,
Timothy M.
Ryan
,
Soenke
Seifert
,
Hiroshi
Sekiguchi
,
Dmitri
Svergun
,
Susana
Teixeira
,
Aurelien
Thureau
,
Thomas M.
Weiss
,
Andrew E.
Whitten
,
Kathleen
Wood
,
Xiaobing
Zuo
Open Access
Abstract: Through an expansive international effort that involved data collection on 12 small-angle X-ray scattering (SAXS) and four small-angle neutron scattering (SANS) instruments, 171 SAXS and 76 SANS measurements for five proteins (ribonuclease A, lysozyme, xylanase, urate oxidase and xylose isomerase) were acquired. From these data, the solvent-subtracted protein scattering profiles were shown to be reproducible, with the caveat that an additive constant adjustment was required to account for small errors in solvent subtraction. Further, the major features of the obtained consensus SAXS data over the q measurement range 0–1 Å−1 are consistent with theoretical prediction. The inherently lower statistical precision for SANS limited the reliably measured q-range to <0.5 Å−1, but within the limits of experimental uncertainties the major features of the consensus SANS data were also consistent with prediction for all five proteins measured in H2O and in D2O. Thus, a foundation set of consensus SAS profiles has been obtained for benchmarking scattering-profile prediction from atomic coordinates. Additionally, two sets of SAXS data measured at different facilities to q > 2.2 Å−1 showed good mutual agreement, affirming that this region has interpretable features for structural modelling. SAS measurements with inline size-exclusion chromatography (SEC) proved to be generally superior for eliminating sample heterogeneity, but with unavoidable sample dilution during column elution, while batch SAS data collected at higher concentrations and for longer times provided superior statistical precision. Careful merging of data measured using inline SEC and batch modes, or low- and high-concentration data from batch measurements, was successful in eliminating small amounts of aggregate or interparticle interference from the scattering while providing improved statistical precision overall for the benchmarking data set.
|
Nov 2022
|
|
B21-High Throughput SAXS
|
Gunjan
Tyagi
,
Jake L.
Greenfield
,
Beatrice E.
Jones
,
William N.
Sharratt
,
Kasim
Khan
,
Dale
Seddon
,
Lorna A.
Malone
,
Nathan
Cowieson
,
Rachel C.
Evans
,
Matthew J.
Fuchter
,
Joao T.
Cabral
Diamond Proposal Number(s):
[98433, 28884]
Open Access
Abstract: The self-assembly of an arylazopyrazole-based photosurfactant (PS), based on cetyltrimethylammonium bromide (CTAB), and its mixed micelle formation with CTAB in aqueous solution was investigated by small angle neutron and X-ray scattering (SANS/SAXS) and UV–vis absorption spectroscopy. Upon UV light exposure, PS photoisomerizes from E-PS (trans) to Z-PS (cis), which transforms oblate ellipsoidal micelles into smaller, spherical micelles with larger shell thickness. Doping PS with CTAB resulted in mixed micelle formation at all stoichiometries and conditions investigated; employing selectively deuterated PS, a monotonic variation in scattering length density and dimensions of the micellar core and shell is observed for all contrasts. The concentration- and irradiance-dependence of the E to Z configurational transition was established in both neat and mixed micelles. A liposome dye release assay establishes the enhanced efficacy of photosurfactants at membrane disruption, with E-PS exhibiting a 4-fold and Z-PS a 10-fold increase in fluorescence signal with respect to pure CTAB. Our findings pave the way for external triggering and modulation of the wide range of CTAB-based biomedical and material applications.
|
Oct 2022
|
|
B21-High Throughput SAXS
|
Diamond Proposal Number(s):
[29646]
Open Access
Abstract: Confining chemotherapy to tumour sites by means of active targeting nanoparticles (NPs) may increase the treatment effectuality while reducing potential side effects. Cubosomes are one of the next-generation drug delivery nanocarriers by virtue of their biocompatibility and bioadhesion, sizeable payload encapsulation and high thermostability. Herein, an active tumour targeting system towards rhabdomyosarcoma (RMS) cells was evaluated. Cubosomes were loaded with helenalin (a secondary metabolite from Arnica plants), which we have previously shown to induce apoptosis in RMS cells. The functionalization of the cubosomes was accomplished to enable binding to membrane receptors and translocation under a magnetic field. RMS cells overexpress CD44 and CD221 on their membrane surface and, therefore, hyaluronic acid (HA, a ligand for CD44) and antibodies (Abs) against CD221 were coupled to cubosomes via electrostatic attraction and the thiol-Michael reaction, respectively. Magnetization of the cubic phase NPs was achieved by embedding superparamagnetic iron oxide NPs (SPIONPs) into the cubic matrix. Single-function and multi-function cubosomes had Im3m cubic phase structures with well-organized lattice patterns. Conjugation with 2% HA or anti-CD221 half Abs and/or 1% SPIONPs showed significantly higher uptake into RMS cells compared to unfunctionalized cubosomes. CD44 and CD221 directed magnetic (triple-function) cubosomes were capable of internalizing into RMS cells in an energy-independent mechanism. Helenalin-laden triple functionalized cubosomes showed limited impact on the viability of control fibroblast cells, while they induced a high degree cytotoxicity against RMS cells. Profound tumour cell death was observed in both two-dimensional (2D) culture and three-dimensional (3D) tumour spheroids.
|
Oct 2022
|
|
B21-High Throughput SAXS
|
Diamond Proposal Number(s):
[24271, 27588]
Open Access
Abstract: Stimuli-responsive materials are crucial to advance controlled delivery systems for drugs and catalysts. Lyotropic liquid crystals (LLCs) have well-defined internal structures suitable to entrap small molecules and can be broken up into low-viscosity dispersions, aiding their application as delivery systems. In this work, we demonstrate the first example of light-responsive cubic LLC dispersions, or cubosomes, using photoswitchable amphiphiles to enable external control over the LLC structure and subsequent on-demand release of entrapped guest molecules. Azobenzene photosurfactants (AzoPS), containing a neutral tetraethylene glycol head group and azobenzene-alkyl tail, are combined (from 10–30 wt %) into monoolein-water systems to create LLC phases. Homogenization of the bulk LLC forms dispersions of particles, ∼200 nm in diameter with internal bicontinuous primitive cubic phases, as seen using small-angle X-ray scattering and cryo-transmission electron microscopy. Notably, increasing the AzoPS concentration leads to swelling of the cubic lattice, offering a method to tune the internal nanoscale structure. Upon UV irradiation, AzoPS within the cubosomes isomerizes within seconds, which in turn leads to squeezing of the cubic lattice and a decrease in the lattice parameter. This squeeze mechanism was successfully harnessed to enable phototriggerable release of trapped Nile Red guest molecules from the cubosome structure in minutes. The ability to control the internal structure of LLC dispersions using light, and the dramatic effect this has on the retention of entrapped molecules, suggests that these systems may have huge potential for the next-generation of nanodelivery.
|
Oct 2022
|
|
B21-High Throughput SAXS
|
Diamond Proposal Number(s):
[16125, 21035]
Open Access
Abstract: Biofermentative production of styrene from renewable carbon sources is crucially dependent on strain tolerance and viability at elevated styrene concentrations. Solvent-driven collapse of bacterial plasma membranes limits yields and is technologically restrictive. Styrene is a hydrophobic solvent that readily partitions into the membrane interior and alters membrane-chain order and packing. We investigate styrene incorporation into model membranes and the role lipid chains play as determinants of membrane stability in the presence of styrene. MD simulations reveal styrene phase separation followed by irreversible segregation into the membrane interior. Solid state NMR shows committed partitioning of styrene into the membrane interior with persistence of the bilayer phase up to 67 mol % styrene. Saturated-chain lipid membranes were able to retain integrity even at 80 mol % styrene, whereas in unsaturated lipid membranes, we observe the onset of a non-bilayer phase of small lipid aggregates in coexistence with styrene-saturated membranes. Shorter-chain saturated lipid membranes were seen to tolerate styrene better, which is consistent with observed chain length reduction in bacteria grown in the presence of small molecule solvents. Unsaturation at mid-chain position appears to reduce the membrane tolerance to styrene and conversion from cis- to trans-chain unsaturation does not alter membrane phase stability but the lipid order in trans-chains is less affected than cis.
|
Jan 2022
|
|
B21-High Throughput SAXS
|
Diamond Proposal Number(s):
[23247]
Abstract: Nanofibres are an interesting phase into which amphiphilic molecules can self-assemble. Described for a large number of synthetic lipids, they were seldom reported for natural lipids like microbial amphiphiles, known as biosurfactants. In this work, we show that the palmitic acid congener of sophorolipids (SLC16:0), one of the most studied families of biosurfactants, spontaneously forms a self-assembled fibre network (SAFiN) at pH below 6 through a pH jump process. pH-resolved in situ small-angle X-ray scattering (SAXS) shows a continuous micelle-to-fibre transition, characterized by an enhanced core–shell contrast between pH 9 and pH 7 and micellar fusion into a flat membrane between pH 7 and pH 6, approximately. Below pH 6, homogeneous, infinitely long nanofibres form by peeling off the membranes. Eventually, the nanofibre network spontaneously forms a thixotropic hydrogel with fast recovery rates after applying an oscillatory strain amplitude out of the linear viscoelastic regime: after being submitted to strain amplitudes during 5 min, the hydrogel recovers about 80% and 100% of its initial elastic modulus after, respectively, 20 s and 10 min. Finally, the strength of the hydrogel depends on the medium's final pH, with an elastic modulus fivefold higher at pH 3 than at pH 6.
|
Sep 2021
|
|
|
|
Open Access
Abstract: We show how to control the formation and alignment of gel ‘noodles’. Nanostructure alignment can be achieved reproducibly by extensional deformation as the filaments form. Using a spinning technique, very long and highly aligned filaments can be made. The Young’s moduli of the gel noodles are similar to that of a bulk gel. By using two syringe pumps in a concentric flow setup, we show that a filament-in-filament morphology can be created.
|
Aug 2021
|
|
B21-High Throughput SAXS
|
Open Access
Abstract: The design of a multipurpose sample cell holder for the high-throughput (HT) beamline B21 is presented. The device is compatible with the robot bioSAXS sample changer currently installed on BM29, ESRF, and P12 Petra IV synchrotrons. This work presents an approach that uses 3D-printing to make hardware alterations which can expand the versatility of HT beamlines at low cost.
|
Dec 2020
|
|
B21-High Throughput SAXS
|
Daniel
Mcdowall
,
Benjamin J.
Greeves
,
Rob
Clowes
,
Kate
Mcaulay
,
Ana M.
Fuentes‐caparrós
,
Lisa
Thomson
,
Nikul
Khunti
,
Nathan
Cowieson
,
Michael C.
Nolan
,
Matthew
Wallace
,
Andrew I.
Cooper
,
Emily R.
Draper
,
Alexander J.
Cowan
,
Dave J.
Adams
Diamond Proposal Number(s):
[20362]
Open Access
Abstract: Amino acid functionalized perylene bisimides (PBIs) form self‐assembled structures in solution, the nature of which depends on the local environment. Using a high‐throughput photocatalysis setup, five PBIs are studied for the hydrogen evolution reaction (HER) under a range of conditions (pH and hole scavenger concentration) across 350 experiments to explore the relationship between supramolecular structure and photocatalytic activity. Using small angle X‐ray scattering (SAXS), NMR spectroscopy and ultraviolet‐visible (UV‐vis) absorption spectroscopy, it is shown that photocatalytic activity is determined by the nature of the self‐assembled aggregate that is formed, demonstrating the potential of self‐assembly to tune activity. There is a clear correlation between the presence of charged flexible cylindrical aggregates and the occurrence of photocatalytic H2 production, with UV–vis spectroscopy indicating that the most active structure type has a distinctive form of π‐aggregation which is proposed to enable efficient charge separation across multiple PBI units.
|
Oct 2020
|
|
