Nanoparticle tracking analysis as a process analytical tool for characterising magnetosome preparations


Nanoparticle Tracking Analysis (NTA) has been employed to measure the particle concentration and size distribution of magnetosomes extracted and purified from Magnetospirillum gryphiswaldense MSR-1, and then exposed to probe ultrasonication for various times, or 1% (w/v) sodium dodecyl sulphate (SDS) for 1 h. Particle concentration increased 3.7-fold over the first 15 min of ultrasonication (from 2 × 108 to >7.3 × 108 particles mL−1), but fell steeply to ∼3.6 × 108 particles mL−1 after 20 min. NTA of untreated magnetosome preparation confirmed a wide particle distribution dominated by larger species (D[1,0] = 312 nm; Dn50 = 261 nm; mode = 243 nm) with no particles in the size range of isolated single magnetosomes. After 5 min of ultrasonication the whole particle size distribution shifted to smaller size (D[1,0] = 133 nm; Dn50 = 99 nm; mode = 36 nm, corresponding to individual magnetosomes), but longer treatment times (15 and 20 min) reversed the previous transition; all characteristic numbers of the particle size distributions increased and very few small particles were detected. Side-by-side comparison of NTA and TEM sizing data revealed remarkable similarity at low ultrasonication times, with both showing single magnetosomes accounted for ∼30% population after 5 min. Exposure of magnetosomes to SDS resulted in a ∼3-fold increase in particle concentration to 5.8 × 108 particles mL−1, narrowing of the size distribution and gross elimination of particles below 60 nm. We conclude that NTA is a rapid cost-effective technique for measuring particle concentration, size distribution and aggregation state of magnetosomes in solution.

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Divisions: College of Engineering & Physical Sciences > School of Infrastructure and Sustainable Engineering > Chemical Engineering & Applied Chemistry
College of Engineering & Physical Sciences
Additional Information: © 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Uncontrolled Keywords: Biomanufacturing,Bioprocessing,Magnetic nanoparticles,Nanobiotechnology,Process analytical technology,Quality control,Biotechnology,Food Science,Biochemistry,Chemical Engineering(all)
Publication ISSN: 1744-3571
Last Modified: 21 May 2024 07:15
Date Deposited: 07 Apr 2021 12:49
Full Text Link: https://www.sci ... 960308521000572
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2021-05
Published Online Date: 2021-03-26
Accepted Date: 2021-03-18
Authors: Fernandez-Castane, Alfred (ORCID Profile 0000-0002-2572-7797)
Overton, Tim W.
Li, Hong
Joseph, Stephan
Ebeler, Moritz
Franzreb, Matthias
Bracewell, Daniel
Thomas, Owen R.T.

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