Biology subjects

Delanoë-Ayari, H.

Publications and source records attributed to Delanoë-Ayari, H..

4 recordsLinked to original sources

bioRxiv2026

Integrating 3D Tumor Models and Microfluidics for Precise Metabolic Control

Understanding how metabolic deprivation shapes tumor behavior requires in vitro systems that faithfully reproduce millimeter-scale biochemical gradients. Here, we introduce MilliFlow3D, an open hydrogel-based microfluidic platform that generates controlled metabolic gradients and supports in situ spheroid formation, real-time imaging, and intact retrieval for spatial analyses. Gradients are generated by passive diffusion across a structured agarose microwell array positioned between two perfusion channels. Using a fluorescent tracer and numerical simulations, we show that MilliFlow3D establishes stable linear gradients with local metabolite levels matching those reported in avascular tumor regions. Using HCT116 colorectal cancer spheroids, we demonstrate that a L-glutamine gradient imposes graded effects on growth and proliferation: spheroid expansion decreases from high- to low-glutamine regions, and Ki-67-positive cells progressively shift toward the periphery under glutamine depletion. Thanks to the platforms spatial accessibility, these phenotypic responses could in the future be coupled to molecular readouts, enabling spatial mapping of metabolic pathway activity along the gradient. Altogether, MilliFlow3D provides a robust and versatile platform to investigate how heterogeneous metabolic landscapes sculpt tumor behavior and to identify context-dependent metabolic vulnerabilities with high analytical precision.

bioengineering↗

bioRxiv2025

Transient volume stabilization reveals the key role a PM permeability in pyroptotic cell swelling.

Pyroptosis, an inflammatory form of cell death, is characterized by massive cell swelling and plasma membrane rupture. Although swelling was recently shown to occur in two steps, the molecular and biophysical mechanisms driving this process remained unclear. Using fast quantitative microscopy, we reveal that between the two swelling phases, cell volume transiently stabilizes despite sustained plasma membrane permeability to ions and small molecules. From a biophysical perspective, the existence of such a plateau is puzzling, as ion pumps should not be able to regulate cell volume under these conditions. To address this, we developed a physical model based on an ion pump and leak framework that incorporates the dynamics of non-selective pore formation. Experimentally, we demonstrate that the plateau phase is controlled by the dynamics of the GSDMD pore enlargement, which is modulated by Ninj1 activation, possibly through intracellular calcium. Ninj1-mediated lesions are also required for the second swelling phase. We further show that fully opened GSDMD pores display an effective hydrodynamic radius slightly above 1.9 nm, providing an insitu upper bound for pore size. Together, our findings demonstrate that pyroptotic volume dysregulation emerges from the successive and interdependent actions of GSDMD and Ninj1, each imparting distinct permeability regimes associated with increased water filtration and decreased ion selectivity due to pore opening. These insights bridge molecular and biophysical perspectives on lytic cell death and may inform the broader understanding of membrane rupture in inflammatory and pathological contexts. Significance StatementAmong programmed modes of lytic cell death, pyroptosis mediated by gasdermin D (GSDMD) and ninjurin-1 (Ninj1) involves dramatic changes in cell shape and large volume fluctuations, fundamentally altering the cells physical properties. By combining optogenetics, quantitative microscopy, and modeling, we show that a progressive increase in plasma membrane pore size drives cell swelling and membrane lysis through successive and interdependent actions of GSDMD and Ninj1, each imparting distinct permeability regimes associated with increased water filtration and decreased ion selectivity. A deeper understanding of these dynamic cell modifications will shed light on the molecular and biophysical mechanisms driving different forms of cell death.

biophysics↗

bioRxiv2022

A microfluidic platform to investigate the role of mechanical constraints on tissue reorganization

Mechanical constraints have a high impact on development processes, and there is a need for new tools to investigate the role of mechanosensitive pathways in tissue reorganization during development. We present here experiments where embryonic cell aggregates are aspired through constrictions in microfluidic channels, generating highly heterogeneous flows and high cell deformations that can be imaged using two-photon microscopy. This approach provides a way to measure in situ local viscoelastic properties of 3D tissues and connect them to intracellular and intercellular events such as cell shape changes and cell rearrangements. Perspectives include applications on organoids to investigate and quantify rheological properties of tissues, and to understand how constraints affect development.

biophysics↗

bioRxiv2021

Quantifying nanotherapeutics penetration using hydrogel based microsystem as a new 3D in-vitro platform

The huge gap between 2D in vitro assays used for drug screening, and the in vivo 3D-physiological environment hampered reliable predictions for the route and accumulation of nanotherapeutics in vivo. For such nanotherapeutics, Multi-Cellular Tumour Spheroids (MCTS) is emerging as a good alternative in vitro model. However, the classical approaches to produce MCTS suffer from low yield, slow process, difficulties in MCTS manipulation and compatibility with high-magnification fluorescent optical microscopy. On the other hand, spheroid-on-chip set-ups developed so far require a microfluidic practical knowledge difficult to transfer to a cell biology laboratory. We present here a simple yet highly flexible 3D-model microsystem consisting of agarose-based microwells. Fully compatible with the multi-well plates format conventionally used in cell biology, our simple process enables the formation of hundreds of reproducible spheroids in a single pipetting. Immunostaining and fluorescent imaging including live high-resolution optical microscopy can be performed in-situ, with no manipulation of spheroids. As a proof-of-principle of the relevance of such in vitro platform for nanotherapeutics evaluation, this study investigates the kinetic and localization of nanoparticles within colorectal cancer MCTS cells (HCT-116). The nanoparticles chosen are sub-5 nm ultrasmall nanoparticles made of polysiloxane and gadolinium chelates that can be visualized in MRI (AGuIX(R), currently implicated in clinical trials as effective radiosensitizers for radiotherapy) and confocal microscopy after addition of Cy 5.5. We show that the amount of AGuIX(R) nanoparticles within cells is largely different in 2D and 3D. Using our flexible agarose-based microsystems, we are able to resolve spatially and temporally the penetration and distribution of AGuIX(R) nanoparticles within MCTS. The nanoparticles are first found in both extracellular and intracellular space of MCTS. While the extracellular part is washed away after few days, we evidenced intracellular localisation of AGuIX(R), mainly within lysosomes compartment, but also occasionally within mitochondria. Our agarose-based microsystem appears hence as a promising 3D in vitro user-friendly platform for investigation of nanotherapeutics transport, ahead of in vivo studies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/427020v2_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@bd48adorg.highwire.dtl.DTLVardef@ee7502org.highwire.dtl.DTLVardef@143ee60org.highwire.dtl.DTLVardef@d6f5ca_HPS_FORMAT_FIGEXP M_FIG Graphical abstract C_FIG

bioengineering↗