M/F Researcher: Development of tools for cellular electroporation and application in stem cells

  • Villejuif, Val-de-Marne
  • CDD
  • Temps-plein
  • Il y a 15 jours
Offer DescriptionThe post-doctoral researcher recruited for this position will participate in the biological validation of two tools for cell electroporation and their application in the context of stem cell electroporation.The first tool is a new photoluminescent probe of the electric potential developed as part of the ANR UFO (Up-conversion ferroelectric nanocrystals for optical sensing of electric potential in biological systems). This photoluminescent probe is based on a transduction mechanism never before explored for this application and which should lead to very high spatiotemporal resolution. The probe consists of ferroelectric nanocrystals (NCFE) doped with rare earth ions whose up-conversion (UC) spectral modulation we will detect (by fluorescence microscopy) as a function of the surrounding electric potential. A biofunctionalized version of these probes will also be tested as optical sensors of changes in the electric potential near cell membranes under different experimental biological conditions.The second tool is a non-invasive (“contactless”) electroporation system developed as part of the ANR Escapade 2 (new bipolar ultra-wideband high power pulsed Source for medical and Defense Applications). The system uses high power electromagnetic sources with two different technologies: (i) one for surface medical applications, i.e., cutaneous or subcutaneous electroporation, (ii) the other will use a device inducing a focusing of the electric field in an area of interest a few centimeters deep, for deep tissue electroporation. The researcher will have to test the ability of these systems to electroporate bacteria and eukaryotic cells without direct contact and optimize the parameters of the applied electric pulses (number of pulses, amplitude, frequency, etc.). The percentage of permeabilized cells will be quantified by flow cytometry using a non-permeant fluorescent marker. A 3-dimensional mapping of the spatial distribution of electroporated cells obtained with these non-invasive systems will be carried out by fluorescence microscopy. This will allow to evaluate the geometry and depth of achievable electroporation. Depending on the progress of the project, the candidate will then evaluate these systems for skin or in vivo tumor electroporation.In parallel, the researcher will study one of the possible applications of these systems: the electro-manipulation of cytosolic calcium in stem cells and its impact on their proliferation and differentiation. The candidate will use specific microsecond electric pulses to control cytosolic calcium oscillations in order to either promote proliferation or facilitate the maturation of human induced neural stem cells (iNSCs, derived from induced pluripotent stem cells, iPSCs) into a neuronal lineage and guide multipotent stromal cells (MSCs) towards a neuronal-like cell phenotype secreting neurotrophic factors (BDNF, GDNF, etc.) essential for neuronal differentiation and survival. The candidate will also test a low amplitude direct current (DC) stimulation to induce neurite growth and guidance- Ensure scientific and technological monitoring in connection with the project
- Plan, design and carry out experiments
- Analyze and interpret the results
- Present the data in writing and orally (in English)
- Participate in the writing of scientific articles in English
- Supervise and collaborate with students and technicians involved in the projectThe postdoctoral researcher chosen for this position will participate in two ANR projects.The Escapade 2 project includes 6 French partners (including 2 industrial ones). Each partner has different expertise and is in charge of the part of the project related to their expertise. The project is based on the use of electromagnetic fields that induce the migration of electric charges near the cell membrane, thus modifying the existing physiological transmembrane potential and leading to membrane permeabilization (electroporation). Electroporation is mainly exploited in the anticancer therapy known as electrochemotherapy (ECT), already used in clinics. Although very effective, fast, and repeatable, ECT usually requires the use of invasive electrodes (needles), which cause pain and tissue damage and require anesthesia or even surgical procedure. This greatly complicates the treatment of deep tumors or those located in sensitive organs by ECT. A process of applying pulsed electric fields in a non-invasive way is therefore highly desirable and is the subject of this project.The ANR UFO project includes 5 French partners. Each partner will bring their unique complementary expertise. Most living cells have an electric potential difference on either side of their plasma membrane resulting from ion concentration differences maintained by ion channels and pumps. The membrane of a neuron can be suddenly (≈1 ms) depolarized (its intracellular potential going from -70 mV to +30 mV) by the synchronized opening of these channels, stimulated by other neurons, thus generating an “action potential” that propagates to other cells to which this neuron is connected by synapses. The monitoring of this depolarization thus informs about synaptic transmission, essential to cognitive and neuromotor processes. The classic approach is to measure electrophysiological activity using micropipettes on a few cells at a time (“patch-clamp”), or with a microelectrode array then recording the extracellular potentials of a set of neurons. For several decades, optical measurement methods have been introduced to simultaneously obtain the electrical activity of a large number of cells simultaneously with high resolution. Apart from a few works exploiting the modulation of electroplasmonic effects of gold nanoparticles or charges of semiconductor nanocrystals, these methods have a number of disadvantages (photobleaching, toxicity…) or limits in measuring an extracellular electrophysiological signal. The aim of the project is to develop and biologically validate a new photoluminescent probe of the extracellular potential based on a mechanism never explored for this application and which should lead to very high spatiotemporal resolution. These probes are ferroelectric nanocrystals (NCFE) doped with rare earth ions whose up-conversion (UC) spectral modulation we will detect as a function of the surrounding electric potential. After biofunctionalization, these probes will be tested as optical sensors of changes in electric potential near cell membranes under different experimental conditions (electric field, electroporation, membrane potential, action potential, etc).The postdoctoral researcher chosen for this position will also collaborate with members of a FETOPEN European project involving 6 organizations from 3 different European countries, including an SME. The aim of the project is to promote functional neuronal regeneration after spinal cord injury (SCI) through an implantable electro-activated technology. Specifically, the project uses high-voltage microsecond electrical stimulations (micropulses) and low-amplitude direct currents on a combination of stem cells (induced neural stem cells and multipotent stromal cells), whose transplantation is facilitated by a biomaterial containing microfibers and microelectrodes. The concept is that the micropulses are capable of imposing and controlling cytosolic calcium oscillations and will thus facilitate proliferation and then neuronal differentiation. Then the direct currents and fibers present in the biomaterial will facilitate and guide axon growth.The postdoctoral researcher will be recruited by the CNRS and will work in the UMR 9018 METSY laboratory (Metabolic and systemic aspect of oncogenesis for new therapeutic approaches) under the direction of Dr. Franck ANDRE and Dr. Lluis MIR. They have numerous collaborations in France and Europe, regularly welcoming interns from these other laboratories. The team also has industrial contacts and a desire to valorize research results.The candidate will benefit from the support of two other members of METSY, also partially involved in the project: a postdoctoral intern and a biologist study engineer. The candidate will also work closely with the other partner laboratories also involved in the project. He/She will participate in all meetings organized by the consortiums.The METSY laboratory is located in research pavilion 2 within the Gustave Roussy Institute in Villejuif. The unit is composed of four teams and more than 40 researchers, clinicians, technicians, postdoctoral interns, and doctoral students. The laboratory is equipped with state-of-the-art equipment (e.g., fluorescence microscopy, flow cytometry, Seahorse technology, cell culture, etc.) and has full access to technological platforms (e.g., imaging, genomics, transcriptomics, animal facility) managed by the Gustave Roussy Institute.RequirementsResearch Field Pharmacological sciences Education Level PhD or equivalentResearch Field Engineering Education Level PhD or equivalentResearch Field Technology Education Level PhD or equivalentLanguages FRENCH Level BasicResearch Field Pharmacological sciences Years of Research Experience 1 - 4Research Field Engineering Years of Research Experience 1 - 4Research Field Technology Years of Research Experience 1 - 4Additional InformationEligibility criteriaThe ideal candidate for this position is an excellent, highly motivated researcher with a PhD in biophysics or stem cell biology/neural regeneration.He/She must master various classical biology techniques: culture of bacteria, animal cells, stem and nerve cells, fluorescence microscopy (calcium), confocal microscopy, two-photon confocal microscopy, flow cytometry, immunohistochemistry, PCR, western blots, etc… Training in animal experimentation can be a plus.He/She must also have knowledge in the field of electroporation and electromagnetism, be able to use oscilloscopes, high voltage electric generators, a 3D printer… Previous experience in electroporation would be a plus.The candidate must appreciate the challenge of new multidisciplinary scientific concepts and have a highly motivated, persistent and results-oriented attitude. We are looking for a candidate interested in working in a multidisciplinary research environment, who has excellent communication skills and is motivated, critical and trustworthy. He/She must be able to work both autonomously and in an interdisciplinary team and in collaboration with other international research teams involved in the project. Good oral and written communication skills in English are essential. Good organizational and planning skills are necessary.Skills
- Manage stocks of reagents, cells, and consumables
- Project management
- Use software and equipment specific to the activity
- Design experimental devices
- Adapt an operating modeSoft skills
- Work in a team
- Know how to report
- Transmit technical know-how
- Transmit knowledge
- Organizational and contact skillsWebsite for additional job detailsWork Location(s)Number of offers available 1 Company/Institute Aspects métaboliques et systémiques de l'oncogénèse pour de nouvelles approches thérapeutiques Country France City VILLEJUIFWhere to apply WebsiteContact CityVILLEJUIFSTATUS: EXPIRED

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