2 research outputs found
Using a Novel Multiplexed Algal Cytological Imaging (MACI) Assay and Machine Learning as a Way to Characterize Complex Phenotypes in Plant-Type Organisms
High-throughput phenotypic profiling
assays, popular for their
ability to characterize alternations in single-cell morphological
feature data, have been useful in recent years for predicting cellular
targets and mechanisms of action (MoAs) for different chemicals and
novel drugs. However, this approach has not been extensively used
in environmental toxicology due to the lack of studies and established
methods for performing this kind of assay in environmentally relevant
species. Here, we developed a multiplexed algal cytological imaging
(MACI) assay, based on the subcellular structures of the unicellular
microalgae, Raphidocelis subcapitata, a toxicology and ecological model species. Several different herbicides
and antibiotics with unique MoAs were exposed to R.
subcapitata cells, and MACI was used to characterize
cellular impacts by measuring subtle changes in their morphological
features, including metrics of area, shape, quantity, fluorescence
intensity, and granularity of individual subcellular components. This
study demonstrates that MACI offers a quick and effective framework
for characterizing complex phenotypic responses to environmental chemicals
that can be used for determining their MoAs and identifying their
cellular targets in plant-type organisms
Lipid Corona Formation from Nanoparticle Interactions with Bilayers and Membrane-Specific Biological Outcomes
<a></a><a>While mixing nanoparticles with certain
biological molecules can result in coronas that afford some control over how engineered
nanomaterials interact with living systems, corona formation mechanisms remain
enigmatic. Here, we report spontaneous lipid
corona formation, i.e. without active mixing, upon attachment to stationary lipid
bilayer model membranes and bacterial cell envelopes, and present ribosome-specific
outcomes for multi-cellular organisms. Experiments show that polycation-wrapped
particles disrupt the tails of zwitterionic lipids, increase bilayer fluidity, and
leave the membrane with reduced ζ-potentials. Computer simulations show contact
ion pairing between the lipid headgroups and the polycations’ ammonium groups leads
to the formation of stable, albeit fragmented, lipid bilayer coronas, while microscopy
shows fragmented bilayers around nanoparticles after interacting with <i>Shewanella oneidensis</i>. Our mechanistic insight
can be used to improve control over nano-bio interactions and to help understand
why some nanomaterial/ligand combinations are detrimental to organisms, like <i>Daphnia magna</i>, while others are not. </a