Thérapie cellulaire du système nerveux central (évaluation de la greffe de cellules souches périphériques)

Les greffes de cellules souches mésenchymateuses (CSM) dans les modèles animaux de pathologies humaines conduisent à une amélioration fonctionnelle, motrice et /ou cognitive. La prolifération des cellules souches neurales endogènes et l'inhibition de la mort cellulaire des cellules nouvellement générées sont certainement impliquées dans zes effets. Nous avons réalisé une analyse détaillée des comportements de cellules issues de la moelle osseuse (CMO) après transplantation in vivo et in vitro. Après injection de CMO dans la veine latérale de la queue, de nombreuses cellules ont mmigré dans l'encéphale et certaine ont acquis un phénotype neuronal ou glial. Nous avons ensuite développé un modèle in vitro de cultures organotypiques d'hippocampe "greffées" par des cellules de moelle osseuse. Nous avons utilisé de CMO ou des CSM sélectionnées après un ou cinq passages en culture, greffées directement sur les tranches ou utilisées en co-culture avec celle-ci. Puis nous avons analysé le transcriptome de ces trois populations cellulaires et avons trouvé que l'esxpression de nombreux gènes impliqués dans l'angiogesèse, la neurogenèse et la mort cellulaire variaient selon les fractions cellulaires. L'ensemble de nos résultats suggèrent que l'amplification cellulaire des cellules issues de la moelle osseuse affecte leur capacité à protéger les tranches d'hippocampe en culture. Ce travail permet d'avoir un aperçu des mécanismes impliqués dans l'établissement d'un microenvironnement favorable à la réparation tissulaire et donne des informations essentielles sur les conditions de sélection et d amplification indispensable à une future utilisation thérapeutiqueBMSCs grafts improve neurological scores and recovery of motor functions in experimental modeles of human diseases. Enhanced proliferation of endognous neural stem cells and suppression of newly generated cell death were also reported. Our contribution concerned a detailed analysis of marrow cell behaviors during their phenotipic transformations after transplantation in vivo and in vitro. After injecting in the lateral tail vein, many of them migrated into the brain, and among those a few acquired neuronal or glial phenotypes. Then, we used an "in vitro graft model" which consisted of a coculture of GFP-expressing BMSCs and hippocampal organotypic slice cultures. Total marrow cells or bone marrow stromal cells at one or five passages were transplanted into hipocampal slices. In other experiments, slices xere co-cultured with, but not in contact with BMSC1P orBMSC5P. Finally a PCR array strategy was implemented for transcriptomic analysis of MCs, BMSC1P and BMSC5P. We found that these cells differentially expressed many genes involved in angiogenis, neurogenis and cell death, that may explain responses that they induce in the nervous tissue. As a conclusion, cellular amplification of BMSCs affects their capacity to slower degradation of organotypic hippocampal slices. This work provides a first glimps of mechanisms implicated in the role of BMSCs in establishing microenvironment more favorable for tissue repair. It also gives essential information on the conditions of selection and induction required for future use in cell therapy as well as their true therapeutic potential.BESANCON-BU Sciences Staps (250562103) / SudocSudocFranceF

Medical Devices Development: the Bottom-up or the Top-down Approach

International audienceBiomedical sensors are often developed under a bottom-up approach, i.e. the researcher point of view or laboratory approach. This is usually the case for microfluidic based integrated systems. The small number of such devices actually translated for use in clinical situations is mostly due to the need of sample pre-treatment by specially trained people and to the fact that industrial transfer had not been taken into account since the very beginning of the development. Conversely, the top-down approach places the end-user at the center of development discussion. In this end-user point of view approach, the participation of industrial, medical and end-users partners more often leads to the design of fully integrated and automated devices which, furthermore, can be manufactured using conventional industrial capabilities. In this opinion communication, we briefly summarize the most common biosensors technologies and we explain how immuno-combined devices may help addressing constraints related to their use in clinical situations in terms of usability by non-trained people, automation and integration

SmarTTransfuser project: toward an automated point-of-care transfusion safety system

BioMed 2013 14-16 November 2013, Bangkok, ThailandBefore each transfusion of red blood cell concentrate, a final ABO compatibility test is carried out at the patient's bedside on a piece of card and interpreted visually. Despite this ultimate test, transfusion accidents still occur due to group incompatibility, which can be lethal. In order to improve this test, we have developed a specific device based on microarrays for the validation of a smart and safe transfuser in the context of critical transfusional situations. This miniaturized device incorporates a biochip to analyze ABO compatibility in order that the hemagglutination reaction of red blood cells with IgMs in solution be replaced by specific capture and concentration of IgMs on microarrays. Results indicate that a specific immunocapture is obtained with globular concentrates and with different total blood. Smarttransfuser is a smart device developed in collaboration with the French Blood Transfusion Center for the optimization at the patient's bedside of an ultimate test prior to transfusion

Functional analysis to drive research and identify regulation requirements: an example with a lithium monitoring device

International audienceMedical device development is often understood as a linear process with design stages occurring sequentially. First stages are usually performed in order to specify the future device definition through interviews/meetings of the end-users, researchers and manufacturers. Because the medical device is original, these first stages mainly involve end-users and researcher. However, regulation constraints and economic reality sometimes makes manufacturers hesitant to base the industrial development on this initial basis. Functional analysis, well known by manufacturers, is a method used to accurately define the final functions of a medical device. In this conference, we estimate that the functional analysis can be put to profit in a more efficient way if researchers and end-users get familiar with it prior to the interview/meeting stages. Although the results of such knowledge democratisation is not demonstrated here, we present the function analysis conducted on a lithium monitoring device according to this multidisciplinary approach. We also show that function analysis can be used not only to drive research actions but also to identify regulation requirements

Test device for Blood transfusion safety: How acoustics can help preventing any red cells incompatibility

International audienceDuring red cells concentrates transfusion, red cells incompatibilities still occur despite the laboratory controls based on immuno-hematologic techniques. Red cells incompatibilities appear when patient’s antibodies bind to red cells to be transfused. Up to now, all pre-transfusion testing are addressed using techniques based on immunology. This is time consuming, expensive and some incompatibility situations cannot be addressed at the patient’s bedside. In this position paper, we propose a completely novel paradigm. Our hypothesis is that red blood cells sensitized by the patient’s antibodies see their deformability greatly reduced. This induces changes of the rheological properties of the “red cells concentrate /patient’s blood” mixture. Studies described in this position paper aim at characterizing these modifications by measuring the characteristics of acoustic waves propagating in the mixture and to produce a mobile and automated acousto-micro-fluidic device which would allow detecting any incompatibility at the patient’s bed side

BLOOD-TO-BLOOD IMMUNOLOGICAL COMPATIBILITY TEST: A possibility with fluorescent immuno-biochips

International audienceOne of the most feared transfusion accident is the haemolytic reaction. A majority of countries impose a compatibility test before each transfusion, at the patient’s bedside or in laboratory. Regardless of the test performed, it does not prevent human errors and nothing ensures an “error free” procedure. Complete crossmatch is the only test ensuring a complete blood compatibility between donors and patients. It relies on the direct or indirect detection of agglutinations which occur when the patient’s plasma is mixed with the red cells to be transfused. It requires extracting plasma. The work described here will help avoid all the immunologic incompatibilities by the use of a compatibility test without plasma extraction. It relies on an immuno- biochip technology in a microfluidic environment with fluorescence detection. This position paper presents preliminary results obtained with artificial samples together with comments on the state of industrial competition and the new device market positioning

SmartTransfuser: a lab-on-chip system for enhancing transfusion security

International audienceBefore each transfusion of red blood cell concentrate, a final ABO compatibility test is carried out at the patient's bedside on a piece of card and interpreted visually. Despite this ultimate test, transfusion accidents still occur due to group incompatibility, which can be lethal. In order to improve this test, we have developed a specific device based on microarrays for the validation of a smart and safe transfuser in the context of critical transfusional situation

Is usability engineering anticipation possible during the initial research actions? An example with the R-Link in vitro self-monitoring device.

International audienceBipolar disorders are severe and complex psychiatric disorders and lithium remains one of the most effective drugs for relapse prevention. Despite its effectiveness, prescription of lithium therapy can be complicated because of its narrow therapeutic range. Furthermore, adherence to treatment is generally low. One means of improving adherence would be to make the patient an actor of his/her treatment. The possibility to control the lithium level with a device that can be used at home would favor this involvement. Although the main part of the work to produce a device is research and development, regulatory analysis, including usability, should not be neglected. Indeed, some design choices should be made taking into account usability constraints. This ensure the fabrication of a device which will be safe, effective and well accepted by the intended users. In this conference, we present actions taken in this direction during the R-Link project

Is usability engineering anticipation possible during the initial research actions? An example with the R-Link in vitro self-monitoring device.

International audienceBipolar disorders are severe and complex psychiatric disorders and lithium remains one of the most effective drugs for relapse prevention. Despite its effectiveness, prescription of lithium therapy can be complicated because of its narrow therapeutic range. Furthermore, adherence to treatment is generally low. One means of improving adherence would be to make the patient an actor of his/her treatment. The possibility to control the lithium level with a device that can be used at home would favor this involvement. Although the main part of the work to produce a device is research and development, regulatory analysis, including usability, should not be neglected. Indeed, some design choices should be made taking into account usability constraints. This ensure the fabrication of a device which will be safe, effective and well accepted by the intended users. In this conference, we present actions taken in this direction during the R-Link project

Immunologic blood transfusion accidents: toward a complete compatibility test at the patient’s bedside

International audienceIn most countries in order to ensure the transfusion safety, a direct compatibility test between the red cell concentrate and the receiver’s blood is performed (crossmatch prior any blood transfusion). In some countries (like France), an ultimate ABO compatibility is required, the test is performed at the patient’s bedside and crossmatch is only performed for patients who present irregular antibodies. Up to now, and whatever the country, no complete solution is able to detect an immunological conflict at the patient’s bedside and to prevent 100% of incompatible transfusions