Biology subjects

McCloskey, M. C.

Publications and source records attributed to McCloskey, M. C..

3 recordsLinked to original sources

bioRxiv2026

Bacterial extracellular vesicles indirectly destabilize a human stem cell-derived blood-brain barrier on-chip through pro-inflammatory stimulation of immune cells

Pathogenic bacterial extracellular vesicles (BEVs) can disrupt the blood-brain barrier (BBB), leading to neuroinflammation. Prior in vitro studies of this process were performed in simple models that may have lacked important physiological factors. We sought to determine if treatment with Escherichia coli-derived BEVs could directly compromise the integrity of a BBB lab-on-chip model or if an immune component was required. Our device featured isogenic human induced pluripotent stem cell-derived brain microvascular endothelial-like cells (BMECs) and pericytes separated by an ultrathin, porous silicon nitride membrane. BEVs and free lipopolysaccharide (LPS) were capable of causing upregulation of intercellular adhesion molecule-1 on the BMEC surfaces, which is important for immune cell recruitment. However, neither BEVs nor LPS at physiological doses caused pronounced loss of BMEC tight junction proteins, nor did they increase barrier permeability to small dye molecules. In contrast, stimulating THP-1 macrophages with BEVs led to increased production of pro-inflammatory cytokines, and conditioned media from the stimulated macrophages disrupted BMEC tight junctions and increased barrier permeability. Our work demonstrates the importance of incorporating an immune component in studies of BEV-mediated disruption of BBB models.

cell biology↗

bioRxiv2022

The Modular μSiM: a Mass Produced, Rapidly Assembled, and Reconfigurable Platform for the Study of Barrier Tissue Models In Vitro

Advanced in vitro tissue chip models can reduce and replace animal experimentation and may eventually support on-chip clinical trials. To realize this potential, however, tissue chip platforms must be both mass-produced and reconfigurable to allow for customized design. To address these unmet needs, we introduce an extension of our {micro}SiM (microdevice featuring a silicon-nitride membrane) platform. The modular {micro}SiM (m-{micro}SiM) uses mass-produced components to enable rapid assembly and reconfiguration by laboratories without knowledge of microfabrication. We demonstrate the utility of the m-{micro}SiM by establishing an hiPSC-derived blood-brain barrier (BBB) in bioengineering and non-engineering, brain barriers focused laboratories. We develop and validate in situ and sampling-based assays of small molecule diffusion as a measure of barrier function. BBB properties show excellent interlaboratory agreement and match expectations from literature, validating the m-{micro}SiM as a platform for barrier models and demonstrating successful dissemination of components and protocols. We then demonstrate the ability to quickly reconfigure the m-{micro}SiM for co-culture and immune cell transmigration studies through addition of accessories and/or quick exchange of components. Because the development of modified components and accessories is easily achieved, custom designs of the m-{micro}SiM should be accessible to any laboratory desiring a barrier-style tissue chip platform.

bioengineering↗

bioRxiv2022

The Modular μSiM Reconfigured: Integration of Microfluidic Capabilities to Study in vitro Barrier Tissue Models under Flow

Microfluidic approaches to study tissue barriers have emerged to address the lack of fluid flow in conventional "open-well" Transwell-like devices. However, microfluidic techniques have not achieved widespread usage in bioscience laboratories because they are not fully compatible with traditional, tried-and-true experimental protocols. To advance barrier tissue research, there is a need for a platform that combines the advantages of both conventional open-well and microfluidic systems. Here, we develop a plug-and-play flow module to add on-demand microfluidic capabilities to a modular microfluidic system featuring a silicon membrane "m-SiM" as an open-well device with live-cell imaging capabilities. The magnetic latching assembly of our design enables bi-directional reconfiguration between open-well and fluidic modes. This design feature allows users to conduct an experiment in an open-well format with established protocols and then add or remove microfluidic capabilities as desired. Our work also provides an experimentally-validated flow model to help select desired flow conditions based on the experimental needs. As a proof-of-concept, we demonstrate flow-induced alignment of endothelial cells and visualize different phases of neutrophil transmigration across an endothelial monolayer under flow. We anticipate that our reconfigurable design will be adopted by both engineering and bioscience laboratories due to the compatibility with standard open-well protocols and the simple flow addition capabilities.

bioengineering↗