Biology subjects

Olivier, T.

Publications and source records attributed to Olivier, T..

5 recordsLinked to original sources

bioRxiv2026

Scalable microvascular networks-on-chip enable 8-week unidirectional perfusion for long-term vascular toxicity screening

Cardiovascular toxicity is a leading cause of late-stage drug attrition, yet current in vitro vascular models lack the longevity and scalability needed to capture clinically relevant responses in mature vasculature. We developed a vascular microphysiological system comprising 32 parallel, self-assembled microvascular networks from primary human endothelial cells and stromal fibroblasts. Networks were unidirectionally perfused by gravity-driven, pump-free flow. They remained functionally perfusable for at least 57 days, the longest duration reported for self-assembled microvascular networks, and underwent progressive maturation characterised by perivascular fibroblast organisation, basement membrane deposition, and matrix remodelling. Variance decomposition confirmed high reproducibility, with intra-plate variability of 3-7% and no operator-dependent effects on network morphometry. Exploiting this extended culture window, we reveal maturation-dependent shifts in endothelial inflammatory responsiveness and cytotoxic susceptibility. Distinct acute and chronic toxicity profiles of clinically used tyrosine kinase inhibitors are resolved, and a concentration- and time-dependent spectrum of sorafenib-induced microvascular responses is produced. These results show that vascular longevity and progressive maturation are key requirements for assessing vascular toxicity, and provide a scalable platform for evaluating acute and chronic drug responses in mature human microvascular tissues.

cell biology↗

bioRxiv2026

A scalable tumor-vasculature-on-chip for CAR T cell trafficking and efficacy studies

Most cellular therapies, like CAR T cells, remain ineffective in solid tumors. This is primarily due to a complex tumor microenvironment (TME), which creates biochemically hostile and often immunosuppressive conditions that limit efficacy of immunotherapies. Besides, cellular therapy efficacy is still often established in traditional 2D cultures that fail to simulate relevant aspects of solid tumor biology. Recent advances in three-dimensional (3D) and organ-on-chip culture systems have provided more physiologically relevant models for immunotherapy testing. These microphysiological systems (MPS) not only offer a 3D environment that alters tumor cell sensitivity to therapy but also enable inclusion of TME components and assessment of processes such as extravasation and infiltration, key steps in CAR T cell activity in vivo. This study focuses on applying an advanced culture technique and further building on the use of a scalable on-chip platform, the OrganoPlate, to grow EpCAM-positive and EpCAM-negative tumor cells in co-culture with an endothelial vessel to study EpCAM-targeting CAR T cell migration and killing kinetics. The CAR T cells specifically targeted and killed EpCAM-positive HT-29 tumor cells while EpCAM-negative A375 tumor cells were not affected. In addition, target cell killing was dependent on the ratio between CAR T and tumor cells (E:T ratio) and was enhanced by addition of IL-2. Inflammatory cytokines like INF-{gamma}, TNF and IL-6 increased overtime in cultures containing CAR T cells. Morphometric analyses of the endothelial compartment showed E:T ratio dependent disruption of endothelial vessels. Additionally, this system was able to distinguish EpCAM ScFv-CD28-CD3z and EpCAM ScFv-TM-4-1BB-CD3z CAR T cells killing abilities and was used for studying the effect of immune checkpoint inhibitors and Temozolomide, a DNA targeting drug, on CAR T cell performance. Altogether, this work adds to the available advanced culture techniques for immunotherapy developers by describing a model that is modular, scalable, and suitable for phenotypic and functional characterization of CAR T cells.

bioengineering↗

bioRxiv2025

Building the blood-brain barrier: a scalable self-assembling 3D model of the brain microvasculature under unidirectional flow

The blood vessels of the central nervous (CNS) system form a tight, protective blood-brain barrier (BBB). This barrier is essential for healthy CNS function but also poses a hurdle in the treatment of increasingly common neurological disorders. Additionally, BBB dysfunction is a hallmark of many neurological diseases, further emphasizing a need for a better understanding of BBB function in health and disease. We present a human self-assembling 3D model of the BBB in a microfluidic cell culture platform that allows culture of 48 models in parallel on one tissue culture plate. Human brain microvascular endothelial cells, pericytes, and astrocytes form highly reproducible BBB vascular networks under unidirectional perfusion and remain viable for a minimum of 14 days. Immunostaining reveals close cell-cell interactions with pericytes and astrocyte end-feet in direct contact with the brain microvasculature. Compared to endothelial monocultures, co-culture with astrocytes or pericytes results in improved barrier function, lower vessel diameters, increased branching, and alignment of the vessels in the direction of fluid flow. These results were most pronounced in tri-cultures containing all three cell types. Unlike similar models previously reported, this brain microvasculature model allows for unidirectional perfusion without the need for pumps and syringes. Combined with its high-throughput nature, this feature renders the model suitable for studies of BBB function in health and disease, and assessment of potential BBB restorative therapies.

neuroscience↗

bioRxiv2025

Modeling Hepatocellular Carcinoma and its microenvironment on a chip

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Its incidence is increasing and is closely related to advanced liver disease. Interactions in the HCC microenvironment between tumor cells and the associated stroma actively regulate tumor initiation, progression, metastasis, and therapy response. Effective drug development increasingly requires advanced models that can be utilized in the earliest stages of compound and target discovery. Here we report a phenotypic screen on an advanced HCC patient-derived chip (PDChip) model. The vascularized HCC PDChip models include relevant cellular players of the HCC microenvironment. We assessed the effect of 28 treatment conditions on a panel of 8 primary HCC tumors and 2 cell lines. Approximately 1200 HCC PDchips were grown under perfusion flow, exposed to treatments, and subsequently assessed for viability, tumor-associated vasculature responses and chemokine and cytokine changes. Although the SoC therapeutics sorafenib and lenvatinib reduced culture viability and produced profound changes in the organization of the vascular beds, they did not affect the tumor cell population in these cultures. Atorvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, reduced tumor viability but did not affect vascular bed organization. Sorafenib, lenvatinib and atorvastatin also affected chemokine and cytokine release. Tocilizumab, galunisertib, and vactosertib decreased the level of IL6, a relevant prognostic marker for HCC, while IL6 was increased by halofuginone. In conclusion, HCC PDChip models enabled a detailed evaluation of drug-induced responses in the tumor and associated microenvironment, highlighting their importance in preclinical research for understanding diseases and developing new drugs.

bioengineering↗

bioRxiv2024

An immunocompetent human kidney on-a-chip model to study renal inflammation and immune-mediated injury

Kidney damage and dysfunction is an emerging health issue worldwide resulting in high morbidity and mortality rates. Numerous renal diseases are recognized to be driven by the immune system. Despite this recognition, the development of targeted therapies has been challenging as knowledge of the underlying mechanism and complex interactions remains insufficient. Recent advancements in the field offer promising avenues for exploring the interplay between renal cells and immune cells and their role in the development of renal inflammation and diseases. This study describes the establishment of a human immunocompetent 3D in vitro co-culture model of the proximal tubule in a high-throughput microfluidic platform that can be used to study renal functionality and inflammatory processes. The model incorporated RPTEC in the top compartment and HUVECs in the bottom compartment cultured under flow and in direct contact with a collagen-I ECM gel resulting in the formation of polarized tubular structures. As an immune component, human primary monocytes of different donors were added to the lumen of the endothelium. Renal inflammation was successfully induced using complement activated serum (CAS) as evident by epithelial morphological changes, increased expression of adhesion molecules, release of pro-inflammatory cytokines, and reduced epithelial viability. Realtime migratory behavior of monocytes showed increased extravasation and migration towards the ECM and Renal compartment upon exposure to CAS with donor-to-donor differences observed. Finally, immune modulatory compounds showed efficacious inhibition of monocyte migration under inflammatory conditions in the microfluidic co-culture model. A successful co-culture model was established and can be applied to study renal functionality in health and disease but also for drug screening due to the compatibility of the platform with automation and relatively high throughput. Overall, the described proximal tubule model has high potential to fill the gap that currently exists to study renal inflammation preclinically.

immunology↗