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Jérôme Charmet

Publications and source records attributed to Jérôme Charmet.

4 recordsLinked to original sources

High-fidelity robotic PCR amplification

Polymerase chain reaction (PCR) underpins modern molecular biology, yet its deployment in emerging domains such as DNA data storage and distributed diagnostics remains constrained by bulky thermocyclers, complex thermal hardware, and contamination-prone workflows. Here, we present an autonomous robotic PCR platform that redefines thermocycling as a motion-controlled process rather than a temperature-controlled device. The system employs a programmable robotic liquid handler to execute PCR entirely within sealed pipette tips, repeatedly immersing and withdrawing reaction volumes in a single temperature-stabilized oil bath to realize denaturation, annealing, and extension steps through precise spatiotemporal control. This architecture eliminates conventional thermocyclers and enables fully enclosed reactions with complete sample recovery. We demonstrate that the robotic system achieves amplification efficiency and sequencing fidelity comparable to high-performance commercial thermocyclers when applied to DNA-encoded datasets. Beyond performance parity, the platform minimizes consumables consumption, suppresses cross-contamination through physical isolation, and supports parallelization through robotic scheduling rather than hardware duplication. Structural contamination control is demonstrated through sealed-tip confinement, validated by no-template control experiments under deliberate challenge conditions. By abstracting PCR thermocycling into a robotically orchestrated manipulation task, this work establishes a generalizable framework for automated biochemical processing and positions robotic control as a central design axis for scalable, low-cost molecular workflows.

q-bio.QM↗

Sample volume as a key design parameter in affinity-based biosensors

Affinity-based biosensors have become indispensable in modern diagnostics and health monitoring. While considerable research has focused on optimizing analyte transport and binding kinetics, a fundamental parameter - sample volume - remains largely underexplored in biosensor design. This is critical because biosensor performance depends on the absolute number of target molecules present, not solely their concentration, making volume a key consideration where sample availability is limited. To address this gap, we developed a mathematical two-compartment model integrating simplified mass transport, Langmuir binding kinetics, and mass conservation under finite volume constraints. The model accurately simulates biosensor binding kinetics and predicts equilibration time and required volume compared to finite-element simulations, whilst achieving more than 100-fold reduction in computational time. From the framework, we derived analytical expressions for biosensor equilibration time and required volume as a function of the Damköhler number, ranging from reaction-limited to transport-limited systems. These analytical solutions predict equilibration time and required volume for a biosensors, providing rapid estimates from first-order biosensor parameters without numerical simulation. We validated this framework experimentally by optimizing flow rate parameters for a quartz crystal microbalance (QCM) biosensor and retrospectively applied optimization guidelines on a published biosensor. The open-source model and analytical expressions allow researchers to gain mechanistic insights, optimize device performance, and make informed design decisions tailored to specific healthcare contexts, including point-of-care testing and resource-constrained environments.

q-bio.QM↗

Tuneable and biodegradable poly(ester amide)s for disposable facemasks

The widespread use of disposable facemasks during the COVID-19 pandemic has led to environmental widespread concern due to microplastic pollution. Biodegradable disposable facemasks are a first step to reducing the environmental impact of pandemics. In this paper we present high-performance facemask components based on novel poly(ester amide) (PEA) grades synthesized from bio-sourced materials and processed into non-woven facemask components. PEA based polymers present an excellent compromise between mechanical performance and biodegradability. Importantly, the properties of the PEA can easily be tuned by changing the ratio of the ester and amides, or variation of diol and diacid part. We synthesized seven polymers which we optimized for biodegradability and processability. Among them, two grades combined electrospinning process compatibility with full degradation within 35 days, using a normalized biodegradation test. The ultra-thin filters thus developed were evaluated for performance on a custom-made characterization bench. The filters achieved a microparticle capture efficiency and breathability comparable to commercial filters. Another PEA grade was optimized to reach optimal visco-thermal properties that made it compatible with solvent-free melt-spinning process as demonstrated with continuous fibres production. Overall, our environmentally friendly solution paves the way for the fabrication of high-performance fibres with excellent biodegradability for the next generation facemasks.

physics.med-ph↗

Flow Rate Independent Multiscale Liquid Biopsy for Precision Oncology

Immunoaffinity-based liquid biopsies of circulating tumor cells (CTCs) hold great promise for cancer management, but typically suffer from low throughput, relative complexity and post-processing limitations. Here we address these issues simultaneously by decoupling and independently optimizing the nano-, micro- and macro-scales of an enrichment device that is simple to fabricate and operate. Unlike other affinity-based devices, our scalable mesh approach enables optimum capture conditions at any flow rate, as demonstrated with constant capture efficiencies, above 75% between 50-200 uL/min. The device achieved 96% sensitivity and 100% specificity when used to detect CTCs in the blood of 79 cancer patients and 20 healthy controls. We demonstrate its post processing capacity with the identification of potential responders to immune checkpoint inhibition therapy and the detection of HER2 positive breast cancer. The results compare well with other assays, including clinical standards. This suggests that our approach, which overcomes major limitations associated with affinity-based liquid biopsies, could help improve cancer management.

q-bio.QM↗