Biology subjects

Aider, J.-L.

Publications and source records attributed to Aider, J.-L..

5 recordsLinked to original sources

bioRxiv2026

Scaffold-Free Acoustic Levitation Platforms Enable Scalable Culture of Neuronal Spheroids and Assembly of Layered Cortico - Striatal Assembloids

Engineering three-dimensional neuronal tissues with defined architecture and functional connectivity remains a critical challenge for applications in disease modeling, drug discovery, and regenerative medicine. Recently, a variety of fabrication methods have arisen, such as bioprinting or manual assembly of organoids, but often struggle with scalability, reproducibility, or maintaining cell viability. Here, two scaffold-free acoustic levitation bioreactors are introduced: one optimized for the culture of uniform neuronal spheroids, and another designed for the structuration of assembloids composed of distinct neuronal identities. Using acoustic standing waves, these platforms enable the contactless manipulation of cells and aggregates, facilitating the formation of highly viable functionally mature spheroids. This study shows that both striatal and cortical cell aggregates formed in acoustic levitation self-organize into spheroids within 24 hours and remain viable up to 10 days under these particular culture conditions without medium renewal. These neuro-spheroids demonstrate healthy development with increased growth and typical terminal differentiation and synaptic maturation. Moreover, concentric cortico-striatal assembloids were successfully structured and cultivated using optimized acoustofluidic chips. Offering versatile and scalable tools for engineering complex neuronal networks, acoustic levitation reveals itself as an innovative approach to 3D neuronal tissue modeling, with broad implications for bioengineering, regenerative medicine and fundamental neuroscience research.

bioengineering↗

bioRxiv2025

Low-Power Acoustic Trapping and Illumination Optimization of Cyanobacteria by Acoustic Layering in Photobioreactors

Space missions require sustainable life support systems capable of producing oxygen and biomass under microgravity. We report the use of acoustic levitation to trap and manipulate the filamentous cyanobacterium Limnospira indica PCC 8005 during parabolic flights. Within a millimeter-scale fluidic chamber, this helical microorganism rapidly assembles into thin layers under a standing ultrasonic wave. Stable trapping in microgravity requires substantially less acoustic power (0.42 mW) than on Earth (1.4 mW), highlighting the potential for energy-efficient bioprocessing in space. Monte Carlo simulations and light attenuation modelling show that layered structuring enhances light penetration, potentially overcoming the "compensation point" limitation in bulk cultures. These findings open new perspectives for photobioreactors using acoustic manipulation to boost photosynthetic efficiency and reduce energy demands for oxygen and biomass production in space.

biophysics↗

bioRxiv2025

Immune Cells Infiltration of Patient Derived Glioblastoma Cells spheroids in Acoustic Levitation in Bulk Acoustic Wave devices

We describe an acoustofluidic device that allows scaffold-free structuration and culture of multi-cellular tumoroids composed of patient-derived glioblastoma cells only or in combination with non-cancerous cell. A PDMS chip of controlled height was created to allow acoustic levitation of cells using a 2 MHz transducer held on top of the chip. Cells are introduced into the chip through a dedicated inlet upstream of the resonant cavity. The specific design of the cavity together with the acoustic field allow the formation of tumoroids of cells in a precise and controlled manner within the levitation chamber. The acoustic and fluidic environment of the device was determined through experiments confronted with numerical simulations. The control of the flow within the chip was optimized to allow long-term culture of tumoroids and injection of cell culture media without disturbing the tumoroids in levitation. The tumoroids can be also structured, with sequential injections of the different cell types. Using microglia, we show that the acoustofluidic device allows the formation and culture in acoustic levitation of tumoroids mixing cancer cells with other cells populating the tumor as well as immune cell infiltration within the tumoroids. These results demonstrate the suitability of acoustofluidic levitation as an original 3D culture method adapted to the exploration of cancer growth at multiple levels.

bioengineering↗

bioRxiv2024

Microgravity stimulates network activity of 3D neuronal spheroids in an acoustic trap

Among biological models, cell culture constitutes an important paradigm that allows rapid examination of cell phenotype and behavior. While cell cultures are classically grown on a 2D substrate, the recent development of organoid technologies represents a paradigmatic shift in biological experimentation as they pave the way for the reconstruction of minimalist organs in 3D. Manipulating these 3D cell assemblies represents a considerable challenge. While there is growing interest in studying the behavior of cells and organs in the space environment, manipulating 3D cultures in microgravity remains a challenge. But with cellular research underway aboard the International Space Station (ISS), optimizing techniques for handling 3D cellular assemblies is essential. Here, in order to cultivate 3D models of spheroids in microgravity, we developed and used an acoustic bioreactor to trap levitating cellular organoids in a liquid cell culture medium. Indeed, in a Bulk Acoustic Wave (BAW) resonator, spherical objects, such as cells, can be maintained in an equilibrium position, inside a resonant cavity, away from the walls. In the acoustic levitation plane, gravity is counterbalanced by the acoustic radiation force (ARF) making it possible to maintain an object even in weightlessness. A dedicated setup was designed and built to perform live calcium imaging during parabolic flights. During a parabolic flight campaign, we were able to monitor the calcium activity of 3D neural networks trapped in an acoustic field during changes in gravity during different parabolas. Our results clearly indicate a change in calcium activity associated with variations in gravity.

biophysics↗

bioRxiv2020

Self-organization and culture of Mesenchymal Stromal Cell spheroids in acoustic levitation

In recent years, 3D cell culture models such as spheroid or organoid technologies have known important developments. Many studies have shown that 3D cultures exhibit better biomimetic properties compared to 2D cultures. These properties are important for in-vitro modeling systems, as well as for in-vivo cell therapies and tissue engineering approaches. A reliable use of 3D cellular models still requires standardized protocols with well-controlled and reproducible parameters. To address this challenge, a robust and scaffold-free approach is proposed, which relies on multi-trap acoustic levitation. This technology is successfully applied to Mesenchymal Stromal Cells (MSCs) maintained in acoustic levitation over a 24-hour period. During the culture, MSCs spontaneously self-organized from cell sheets to cell spheroids with a characteristic time of about ten hours. Each acoustofluidic chip could contain up to 30 spheroids in acoustic levitation and four chips could be ran in parallel, leading to the production of 120 spheroids per experiment. Various biological characterizations showed that the cells inside the spheroids were viable, maintained the expression of their cell surface markers and had a higher differentiation capacity compared to standard 2D culture conditions. These results open the path to long-time cell culture in acoustic levitation of cell sheets or spheroids for any type of cells.

bioengineering↗