Biology subjects

Adamatzky, A.

Publications and source records attributed to Adamatzky, A..

3 recordsLinked to original sources

bioRxiv2017

Programmable transport of micro- and nanoparticles by Paramecium caudatum

We exploit chemo- and galvanotactic behaviour of Paramecium caudatum to design a hybrid device that allows for controlled uptake, transport and deposition of environmental micro- and nanoparticulates in an aqueous medium. Manipulation of these objects is specific, programmable and parallel. We demonstrate how device operation and output interpretation may be automated via a DIY low-cost fluorescence spectrometer, driven by a microprocessor board. The applications of the device presented range from collection and detoxification of environmental contaminants (e.g. nanoparticles), to micromixing, to natural expressions of computer logic.

microbiology↗

bioRxiv2017

Studies in Particle Sorting by Paramecium Cilia Arrays

Motile cilia are cell-surface organelles whose purposes, in ciliated protists and certain ciliated vertebrate epithelia, include generating fluid flow, chemosensation, mechanosensation and substance uptake. Certain properties of cilia arrays, such as beating synchronisation and manipulation of external proximate particulate matter, are considered emergent, but remain incompletely characterised despite these phenomena having being the subject of extensive modelling. This study constitutes a laboratory experimental characterisation of one of the emergent properties of motile cilia; microparticle manipulation. The work demonstrates through automated videomicrographic particle tracking that interactions between microparticles and somatic cilia arrays of the ciliated model organism Paramecium caudatum constitute a form of rudimentary sorting. Small particles are drawn into the organisms proximity by cilia-induced fluid currents at all times, whereas larger particles may be held immobile at a distance from the cell margin when the cell generates characteristic feeding currents in the surrounding media. These findings can contribute to the design and fabrication of biomimetic cilia, with potential applications to the study of ciliopathies.

microbiology↗

bioRxiv2017

Toxicity and applications of internalised magnetite nanoparticles within live Paramecium caudatum cells

The nanotechnology revolution has allowed us to speculate on the possibilities of hybridising nanoscale materials with live substrates, yet significant doubt still remains pertaining to the effects of nanomaterials on biological matter. In this investigation we cultivate the ciliated protistic pond-dwelling microorganism Paramecium caudatum in the presence of excessive quantities of magnetite nanoparticles in order to assess both potential beneficial applications for this technique as well as any deleterious effects on the organisms health. Our findings indicate that these nanoparticles are well-tolerated by paramecia, who were observed to consume in quantities exceeding 10% of their body volume: cultivation in the presence of magnetite nanoparticles does not alter P. caudatum cell volume, swim speed, growth rate or peak colony density and cultures may persist in nanoparticle-contaminated medium for many weeks. We demonstrate that P. caudatum cells ingest starch coated magnetite nanoparticles which facilitates their being magnetically immobilised whilst maintaining apparently normal ciliary dynamics, thus demonstrating that nanoparticle biohybridisation is a viable alternative to conventional forms of ciliate quieting. Ingested magnetite nanoparticle deposits appear to aggregate, suggesting that (a) the process of being internalised concentrates and therefore detoxifies nanomaterial suspensions in aquatic environments and (b) P. caudatum is a candidate organism for programmable nanomaterial manipulation and delivery.

microbiology↗