Mon projet de thèse a consisté en l’identification et la caractérisation moléculaire et immunologique de patients présentant une susceptibilité accrue aux infections fongiques par Candida sp. dans le syndrome Mendélien de candidose cutanéo-muqueuse chronique (CCMC).La CCMC est caractérisée par des infections persistantes ou récurrentes de la peau, des ongles et des muqueuses par les champignons Candida, principalement C. albicans. Elle est fréquemment associée à d’autres infections opportunistes dans certaines immunodéficiences primaires ou acquises, ou bien elle peut être associée à un tableau auto-immun. La CCMC peut finalement être isolée (CCMCi) sans autre tableau clinique sévère: la plupart des cas rapportés sont sporadiques, mais il existe également des cas familiaux avec une hérédité mendélienne autosomique principalement dominante (AD) ou plus rarement récessive (AR).Basés sur les données de la littérature, qui démontrent un rôle majeur de l’immunité dépendante des IL-17s dans la résistance aux infections mucocutanées vis-à-vis de C. albicans et nos résultats récents, qui démontrent un défaut de cette immunité dans certaines immunodéficiences primaires associées à une CCMC [les syndromes AD-HIES et AR APS-1, ainsi que chez les patients déficients en CARD9, nous avons émis l’hypothèse que parmi les patients atteints de CCMCi, certains pourraient présenter un défaut génétique affectant spécifiquement l’immunité IL-17-dépendante. Au début de ma thèse, j’ai participé à l’identification des deux premières étiologies génétiques de la CCMCi : le défaut autosomique récessif (AR) complet en IL-17RA et autosomique dominant (AD) en IL-17F. Plus récemment, j’ai identifié la troisième et la plus fréquente étiologie génétique de la CCMC par l’identification de mutations gain de fonction dans le gène STAT1 suite à une approche explorant l’ensemble du génome (séquençage de l’ensemble des exons). Ces mutations engendrent une « hyper-réponse » aux interférons de type I et II et à l’IL-27 qui inhibent la différentiation des lymphocytes T sécréteurs d’IL-17, impliqués dans l’immunité mucocutanée vis-à-vis de C. albicans chez l’homme.En conclusion, nous avons identifié, en 2011, des trois premières étiologies génétiques de la CCMCi, avec les défauts AR en IL-17RA, AD en IL-17F et des mutations gain-de-fonction de STAT1, toutes associées à un défaut de l’immunité dépendante de l’IL-17. Des mutations gain-de-fonction de STAT1 représentent à ce jour la cause génétique la plus fréquente de la CCMCi avec au total 94 patients rapportés dans la littérature depuis 2011. Nous avons ainsi démontré que la CCMCi est une immunodéficience primaire, associée à un défaut de l’immunité réalisée par les IL-17s. Ces travaux ont des implications majeures dans le domaine immunologique avec la description et la caractérisation des mécanismes biologiques impliqués dans l’immunité protectrice spécifique de C. albicans et une meilleure compréhension des mécanismes physiopathologiques associés à une susceptibilité accrue aux infections fongiques, dans des conditions naturelles d’infection ; et dans le domaine médical, avec la possibilité de diagnostics moléculaires, un conseil génétique en cas de diagnostic positif, une meilleure prise en charge des patients. / My project consists in the molecular and immunological identification and characterization of patients with increased susceptibility to fungal infections with Candida sp. suffering from the Mendelian syndrome of chronic mucocutaneous candidiasis (CMC).CMC is characterized by persistent or recurrent infections of the skin, nails and mucosae by Candida fungi, especially C. albicans. CMC is frequently associated with other opportunistic infections in some acquired or primary immunodeficiencies, or can be associated with autoimmune disorders. Finally, CMC may be present as an isolated form (chronic mucocutaneous candidiasis disease or CMCD) without any other severe infectious or autoimmune clinical manifestation: most reported cases are sporadic, but there are also familial cases with autosomal dominant (AD) or recessive (AR) Mendelian inheritance.Based the literature, which demonstrated a major role of IL-17 cytokines in mucocutaneous immunity with C. albicans, and our recent results, which show an impairment of IL-17 immunity in some primary immunodeficiencies associated with CMC (AD-HIES syndrome, AR APS-1, and CARD9-deficient patients), we hypothesized that among CMCD patients, some might have a genetic defect affecting specifically the IL-17-dependent immunity.At the beginning of my PhD, I participated in the identification of the first two genetic etiologies of CMCD: complete AR IL-17RA and partial AD IL-17F deficiencies. More recently, I identified the third and most common genetic etiology of CMCD by identifying gain of function mutations in the STAT1 gene following an approach exploring the whole genome (sequencing of all exons). These mutations are responsible for a "hyper-response" to type I and II interferons and IL-27, which inhibit the differentiation of IL-17-producing T cells. Impaired IL-17 immunity results in reduced mucocutaneous defenses against C. albicans in humans. In conclusion, we have identified in 2011, the first three genetic etiologies of CMCD with AR IL-17RA and AD IL-17F deficiencies and gain-of-function STAT1 mutations, all associated with an impaired IL-17-dependent immunity. Gain-of-function STAT1 mutations represent the most frequent genetic cause of CMCD with a total of 94 patients reported in the literature since 2011. We have shown that CMCD is a primary immunodeficiency associated with inborn errors of IL-17 immunity. This work has important implications in the field of immunology with the description and characterization of the biological mechanisms involved in protective immunity specific to C. albicans and a better understanding of the pathophysiological mechanisms associated with increased susceptibility to fungal infections in natural conditions of infection, and in the medical field, with the possibility of molecular diagnostics, genetic counseling for a positive diagnosis, and a better follow-up of the patients.

L'évaluation médico-économique (EME) joue un rôle de plus en plus important dans le développement des recommandations cliniques et les décisions de prix et remboursement des produits de santé, notamment des vaccins. L'EME des vaccins fait l'objet de procédures et de recommandations méthodologiques spécifiques, distinctes des médicaments, dans de nombreux pays. Cette thèse illustre et répertorie les différentes questions méthodologiques concernant l'EME des programmes de vaccination sur la base de six études : estimation de la morbidité, mortalité et coûts liés aux infections à cytomégalovirus chez les receveurs de greffe d'organe solide ; description de l'état de santé subjectif et qualité de vie liée à la santé chez les femmes atteintes de candidose vulvovaginale récurrente (CVVR) ; revue critique des EME de la vaccination de rappel contre la coqueluche ; revue critique des EME de la vaccination contre le rotavirus ; analyse coût-efficacité de la vaccination antigrippale chez les personnes de 50 à 64 ans ; analyse coût-efficacité d'un vaccin antigrippal quadrivalent en Ontario. L'EME des programmes de vaccination nécessite de prédire l'effet d'un vaccin dans la vie réelle à partir d'essais cliniques, ce qui est particulièrement difficile pour plusieurs raisons : l'épidémiologie d'une infection peut varier dans le temps et l'espace, la réduction du risque d'infection après vaccination est différente de celle du risque de maladie, et la vaccination peut conduire à une augmentation ou diminution du risque chez les personnes non-vaccinées. De plus, la mesure et la valorisation des effets sur la qualité de vie soulèvent des questions méthodologiques et requièrent des choix normatifs liés aux faits que de nombreux vaccins ciblent les enfants, et que la réduction du risque peut améliorer la qualité de vie en dehors des périodes de maladie. Nous établissons finalement des recommandations pour les futures EME de programmes de vaccination, concernant la définition des stratégies à comparer, le choix de structure de modèle, l'estimation des paramètres cliniques et épidémiologiques, et la mesure et la valorisation de la qualité de vie et des coûts / Economic evaluation plays an increasingly important role in the development of clinical recommendations and pricing and reimbursement decisions for healthcare interventions, and particularly for vaccination. Specific processes and methodological recommendations have been developed for the economic evaluation of vaccines in many countries. This thesis identifies and illustrates different methodological questions about the economic evaluation of vaccination programs based on six studies: estimation of morbidity, mortality and costs associated with cytomegalovirus infections among receivers of solid organ transplant; description of subjective health state and quality of life among women with recurrent vulvovaginal candidosis; critical review of economic evaluations of pertussis booster vaccination; critical review of economic evaluations of rotavirus vaccination; cost-effectiveness analysis of influenza vaccination for people aged 50 to 64 years; cost-effectiveness analysis of a quadrivalent influenza vaccine in Ontario. The economic evaluation of vaccines requires predicting the effectiveness of vaccination based on clinical trial data, which is particularly difficult for several reasons: the epidemiology of an infection may vary over time and space, the effectiveness against infection may differ from effectiveness against disease, and vaccination may lead to an increase or decrease in the burden of disease among non-vaccinated persons. In addition, the measurement and valuation of effects of vaccination on quality of life raises methodological questions and requires normative choices related to the facts that many vaccines target children and that the reduction in risk may improve quality of life outside illness periods. We finally establish recommendations for future economic evaluations of vaccination programs, related to the definition of vaccination strategies to compare, the choice of model structure, the estimation of clinical and epidemiological parameters, and the measure and valuation of quality of life and costs

La candidose oro-pharyngée (COP) est l’infection fongique opportuniste la plus commune chez les individus infectés par le VIH-1. La production des cytokines Il-17 et Il-22 par les lymphocytes Th17 est importante lors de la résolution de la COP, puisque ces cytokines induisent la production de peptides antifongiques et le recrutement des neutrophiles polymorphonucléaires. Toutefois, les lymphocytes Th17 sont préférentiellement déplétés chez les individus infectés par le VIH-1. Le modèle de COP chez la souris transgénique (Tg) CD4C/HIVMutA, exprimant les gènes nef, env et rev du VIH-1, permettra de déterminer si des altérations quantitatives et/ou fonctionnelles des sous-populations de lymphocytes T CD4+ causent la sensibilité à la candidose. Les sous-populations Th1, Th2, Th1Th17, Th17 et Treg, ainsi que leurs précurseurs, les lymphocytes T CD4+ naïfs, sont sévèrement déplétées dans les ganglions cervicaux de la souris Tg. Cependant, les lymphocytes T CD4+ naïfs conservent la capacité à se différencier in vitro en présence de cytokines polarisantes et à produire les cytokines typiques des diverses sous-populations. De plus, les cytokines requises pour la polarisation des lymphocytes T CD4+ naïfs n’étaient pas réduites dans les ganglions cervicaux des souris Tg, 7 jours après le début de l’infection. Les gènes S100a8, Ccl20, Il17 et Il22 étaient surexprimés en réponse à la COP chez la souris non-Tg, mais pas chez la souris Tg. Le traitement de souris Tg infectées à l’aide de la combinaison des cytokines Il-17 et Il-22 réduit significativement la charge fongique buccale de C. albicans et le nombre d’hyphes dans l’épithélium de la langue et restaure la capacité à surexprimer des gènes S100a8, Ccl20 et Il22. Ces résultats démontrent que la perturbation de l’induction de l’immunité innée par l’Il-17 et l’Il-22 augmente la susceptibilité à la COP chez la souris Tg. / Oropharyngeal candidiasis (OPC) is the most common opportunistic fungal infection in HIV-infected individuals. OPC resolution involves Il-17 and Il-22 production by Th17 cells through oral antifungal peptide production and polymorphonuclear neutrophil recruitment. Conversely, Th17 cells are preferentially depleted in HIV-infected individuals. The OPC model in transgenic (Tg) mice expressing nef, env and rev from the HIV-1 genome enables the study of the quantitative and functional defects of the CD4+ T-cell subpopulations. The Th1, Th2, Th1Th17, Th17 and Treg subpopulations, as well as naïve CD4+ T-cell precursors, are severely depleted in the cervical lymph nodes (CLNs) of Tg mice. However, the differentiation capacity of naïve CD4+ T-cells in response to polarizing cytokines was maintained in vitro in Tg mice, as well as their ability to produce the signature cytokines of the various subpopulations. Moreover, the polarizing cytokines were not reduced in the CLNs of Tg mice, 7 days after infection. The S100a8, Ccl20, Il17 and Il22 genes were up-regulated in response to OPC in non-Tg mice, but not in Tg mice. Treatment of infected Tg mice with a combination of Il-17 and Il-22 cytokines significantly reduced the oral fungal burdens of C. albicans as well as the number of hyphae in the tongue epithelium. Treatment also restored S100a8, Ccl20 and Il22 up-regulation in Tg mice. These results show that defective induction of innate immunity, normally mediated by Il-17 and Il-22, increases the susceptibility to OPC in these Tg mice.

O antisséptico cloreto de cetilpiridíneo (CCP) demonstrou ser eficaz como alternativa terapêutica aos antifúngicos em candidose oral, porém, apresenta baixa substantividade. Para aumentar sua biodisponibilidade surge a possibilidade de incorporá-lo num sistema de liberação lenta composto por filmes poliméricos nanofibrílicos. O objetivo deste estudo foi preparar filmes nanofibrílicos através de eletrofiação e incorporar CCP, fazer sua caracterização térmica e morfológica, além de análise microbiológica dos filmes contendo CCP frente a cepas de Candida albicans. O fármaco CCP foi adicionado a três soluções poliméricas, de álcool polivinílico (PVA), polivinilpirrolidona (PVP) e a de PVP/PM [Poli (metacrilato de metila-co-acrilato de etila-co-metacrilato de amônio)] em 5% de concentração. As soluções foram avaliadas quanto à condutividade, viscosidade e tensão superficial e, posteriormente, passaram pelo processo de eletrofiação para obtenção de filmes nanofibrílicos. Os filmes nanofibrílicos foram caracterizados através de análise morfológica (microscopia eletrônica de varredura - MEV), análise térmica (análise termogravimétrica - TGA e calorimetria exploratória diferencial - DSC) e análise química (espectro de infravermelho da transformada de Fourier - FTIR). A eficiência de encapsulação de CCP nas nanofibras, o perfil cinético de liberação das nanofibras e a permeação em mucosa suína (células de Franz) foram avaliados por espectrofotometria. Foi ainda avaliada a concentração de CCP a ser incorporada (de 0,05 a 5%) em nanofibra para que a fração liberada seja a mínima fungicida frente às cepas de C. albicans susceptíveis, pela técnica de disco-difusão, comparada ao miconazol 5% (MCZ). Nestas condições, a solução de PVA apresentou a maior condutividade, viscosidade e tensão superficial. CCP aumentou a condutividade. Ambos, CCP e PM não alteram a tensão superficial do PVP. PM reduziu a viscosidade. A solução de PVP/PM formou o filme mais uniforme e com menos beads. Os termogramas (TGA/DSC) sugerem que o processo de eletrofiação diminiu a cristalinidade de CCP. A eficiência de encapsulação de CCP alcança 99%. A taxa de liberação de CCP encapsulado foi lenta durante o período experimental de 24h. Quando em filme nanofibrílicos, a atividade fungicida de CCP 2,5% e de MCZ 5% foi similar, mas somente MCZ foi fungistático. O filme nanofibrílico contrai em contato com o meio de cultura. Pode-se concluir que filmes nanofibrílicos de PVP/PM com CCP tem potencial para uso como alternativa para tratamento de infecções orais causadas por Candida. / The aim of this study was to prepare electrospun nanofiber films cetylpyridinium chloride (CPC) incorporated test their potential use as antifungal therapy against Candida albicans. CPC was incorporated to three different polymeric solutions, one containing polyvinyl alcohol (PVA), the second containing polyvinylpyrrolidone (PVP) and the third prepared with PVP and poly (methyl methacrylate-co-ethyl acrylate-co-methacrylate ammonium) (PMMA). These polymeric solutions were evaluated as to conductivity, viscosity and surface tension, then subjected to a electrospinning process to obtain nanofiber films. The morphology and structure of nanofiber films were analyzed using scanning electron microscopy (SEM). The characterization of nanofiber films was performed by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The encapsulation efficiency of the CPC nanofibers and the release kinetic profile of CPC and porcine mucosa permeation (Franz cells) were assessed by spectrophotometry. It was also assessed the concentration of CPC to be incorporated (from 0.05 to 5%) in nanofiber to be minimal fungicidal fraction released against strains of C. albicans by disk diffusion tests, compared to 5% miconazole (MCZ). Under these conditions, the PVA solution showed the highest conductivity, viscosity and surface tension. CPC increased conductivity. Both CPC and PMMA did not alter the surface tension of PVP. PMMA reduced viscosity. The solution of PVP/PMMA formed a more uniform film with less beads. Thermograms (TGA / DSC) suggested that the electrospinning process changes the crystallinity of CPC. The encapsulation efficiency reaches 99% of CPC. The release rate of encapsulated CPC was slow during the experimental period of 24 hours. In a nanofibrilic film, the fungicidal activity of CPC 2.5% and 5% MCZ was similar, but only MCZ proved fungistatic action. The nanofibrilic film shows contraction in contact with the culture medium. It can be concluded that nanofibrilic films PVP/PMMA with CPC has potential for use as an alternative for the treatment of oral infections caused by Candida.

Le cancer de la cavité orale représente un problème important de santé publique en France où les taux d’incidence sont parmi les plus élevés au monde. Bien qu’une détection précoce soit possible, ces tumeurs sont souvent diagnostiquées à un stade avancé et sont ainsi responsables de plus de 1500 décès par an. L’objectif général est de clarifier le rôle et l’impact des différents facteurs de risque dans la survenue des cancers de la cavité orale en France, notamment d’examiner de façon détaillée le rôle du tabac et de l’alcool par localisation anatomique précise, et d’étudier les associations avec d’autres facteurs de risque potentiels (indice de masse corporelle, antécédents médicaux, antécédents familiaux de cancer, consommations de café et de thé). Ce travail s’appuie sur les données d’une large étude cas-témoins en population générale, l’étude ICARE. Il porte sur un sous-ensemble de ces sujets (772 cas de cancer de la cavité orale et 3555 témoins). Les résultats montrent que le tabac augmente le risque de cancer de la cavité orale même pour des quantités et/ou durées faibles, alors que l’augmentation de risque liée à l’alcool n’est observée que pour de fortes consommations. L’effet conjoint du tabac et de l’alcool est plus que multiplicatif. Les associations avec les consommations d’alcool et de tabac varient selon la sous localisation : les associations les plus fortes sont observées pour le plancher buccal, les plus faibles pour les gencives. L’étude des autres facteurs de risque a mis en évidence : une association inverse entre risque de cancer de la cavité orale et indice de masse corporelle, avec un risque plus faible chez les personnes en surpoids ou obèses ; un risque augmenté lorsqu’un parent du 1er degré a été atteint d’un cancer des voies aéro-digestives supérieures ; un risque élevé chez les personnes présentant des antécédents de candidose buccale ; un risque diminué chez les consommateurs de thé ou de café. A partir de ces premiers résultats, il est envisagé de construire un score prédictif de cancer de la cavité orale permettant d’identifier les sujets à risque élevé sur lesquels cibler préférentiellement les actions de dépistage. / Cancer of the oral cavity is a major public health problem in France. Incidence rates are among the highest in the world. Although early detection is possible and effective, these tumors are often diagnosed at an advanced stage and are thus responsible for over 1,500 deaths per year. The objective of this work was to clarify the role and impact of several risk factors in the development of cancers of the oral cavity in France, particularly to examine the role of tobacco smoking and alcohol drinking by subsite, and to explore associations with other potential risk factors (body mass index, medical history, family history of cancer, tea and coffee consumption). We analyzed detailed data from 772 cases of cancer of the oral cavity and 3555 controls included in a large population-based case-control study, the ICARE study. Tobacco smoking increased the risk of oral cavity cancer even for low quantities and/or durations, while alcohol drinking increased this risk only in heavy drinkers. The combined effect of tobacco and alcohol was greater than multiplicative. Associations with alcohol and tobacco consumption varied depending on subsite: the strongest associations were observed for the floor of the mouth, the lowest for the gums. The analysis of other risk factors showed: an inverse association between oral cancer risk and body mass index with a lowered risk among overweight or obese; an increased risk associated with an history of head and neck cancer in 1st degree relatives; an elevated risk in people with a history of oral candidiasis and a decreased risk among consumers of tea or coffee. From these first results, it is planned to develop an oral cancer risk score to identify high-risk individuals for screening.

O antisséptico cloreto de cetilpiridíneo (CCP) demonstrou ser eficaz como alternativa terapêutica aos antifúngicos em candidose oral, porém, apresenta baixa substantividade. Para aumentar sua biodisponibilidade surge a possibilidade de incorporá-lo num sistema de liberação lenta composto por filmes poliméricos nanofibrílicos. O objetivo deste estudo foi preparar filmes nanofibrílicos através de eletrofiação e incorporar CCP, fazer sua caracterização térmica e morfológica, além de análise microbiológica dos filmes contendo CCP frente a cepas de Candida albicans. O fármaco CCP foi adicionado a três soluções poliméricas, de álcool polivinílico (PVA), polivinilpirrolidona (PVP) e a de PVP/PM [Poli (metacrilato de metila-co-acrilato de etila-co-metacrilato de amônio)] em 5% de concentração. As soluções foram avaliadas quanto à condutividade, viscosidade e tensão superficial e, posteriormente, passaram pelo processo de eletrofiação para obtenção de filmes nanofibrílicos. Os filmes nanofibrílicos foram caracterizados através de análise morfológica (microscopia eletrônica de varredura - MEV), análise térmica (análise termogravimétrica - TGA e calorimetria exploratória diferencial - DSC) e análise química (espectro de infravermelho da transformada de Fourier - FTIR). A eficiência de encapsulação de CCP nas nanofibras, o perfil cinético de liberação das nanofibras e a permeação em mucosa suína (células de Franz) foram avaliados por espectrofotometria. Foi ainda avaliada a concentração de CCP a ser incorporada (de 0,05 a 5%) em nanofibra para que a fração liberada seja a mínima fungicida frente às cepas de C. albicans susceptíveis, pela técnica de disco-difusão, comparada ao miconazol 5% (MCZ). Nestas condições, a solução de PVA apresentou a maior condutividade, viscosidade e tensão superficial. CCP aumentou a condutividade. Ambos, CCP e PM não alteram a tensão superficial do PVP. PM reduziu a viscosidade. A solução de PVP/PM formou o filme mais uniforme e com menos beads. Os termogramas (TGA/DSC) sugerem que o processo de eletrofiação diminiu a cristalinidade de CCP. A eficiência de encapsulação de CCP alcança 99%. A taxa de liberação de CCP encapsulado foi lenta durante o período experimental de 24h. Quando em filme nanofibrílicos, a atividade fungicida de CCP 2,5% e de MCZ 5% foi similar, mas somente MCZ foi fungistático. O filme nanofibrílico contrai em contato com o meio de cultura. Pode-se concluir que filmes nanofibrílicos de PVP/PM com CCP tem potencial para uso como alternativa para tratamento de infecções orais causadas por Candida. / The aim of this study was to prepare electrospun nanofiber films cetylpyridinium chloride (CPC) incorporated test their potential use as antifungal therapy against Candida albicans. CPC was incorporated to three different polymeric solutions, one containing polyvinyl alcohol (PVA), the second containing polyvinylpyrrolidone (PVP) and the third prepared with PVP and poly (methyl methacrylate-co-ethyl acrylate-co-methacrylate ammonium) (PMMA). These polymeric solutions were evaluated as to conductivity, viscosity and surface tension, then subjected to a electrospinning process to obtain nanofiber films. The morphology and structure of nanofiber films were analyzed using scanning electron microscopy (SEM). The characterization of nanofiber films was performed by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The encapsulation efficiency of the CPC nanofibers and the release kinetic profile of CPC and porcine mucosa permeation (Franz cells) were assessed by spectrophotometry. It was also assessed the concentration of CPC to be incorporated (from 0.05 to 5%) in nanofiber to be minimal fungicidal fraction released against strains of C. albicans by disk diffusion tests, compared to 5% miconazole (MCZ). Under these conditions, the PVA solution showed the highest conductivity, viscosity and surface tension. CPC increased conductivity. Both CPC and PMMA did not alter the surface tension of PVP. PMMA reduced viscosity. The solution of PVP/PMMA formed a more uniform film with less beads. Thermograms (TGA / DSC) suggested that the electrospinning process changes the crystallinity of CPC. The encapsulation efficiency reaches 99% of CPC. The release rate of encapsulated CPC was slow during the experimental period of 24 hours. In a nanofibrilic film, the fungicidal activity of CPC 2.5% and 5% MCZ was similar, but only MCZ proved fungistatic action. The nanofibrilic film shows contraction in contact with the culture medium. It can be concluded that nanofibrilic films PVP/PMMA with CPC has potential for use as an alternative for the treatment of oral infections caused by Candida.

Hypothèse : Le nanobroyage d'une suspension de nystatine augmentera son efficacité antifongique in vitro et in vivo. Méthode : Une nanosupension de nystatine a été obtenue en utilisant le broyage humide. Elle a été caractérisée pour sa distribution de taille des particules et pour sa teneur en principe actif. L'activité in vitro a été évaluée contre les souches de C. albicans SC5314 et LAM-1 aux concentrations 12.5 μg/mL jusqu'à 5000 μg/mL. L'efficacité in vivo a été évaluée en utilisant un modèle murin de candidose oropharyngée. Résultats : La taille médiane des particules de la nanosuspension de nystatine a été réduite de 6577 nm à 137 nm. L'analyse CLHP a demontré une teneur de 98.7 ± 0.8%. L'activité in vitro de la nanosuspension était supérieure à la suspension aux concentrations 100 μg/mL à 5000 μg/mL. La charge fongique orale était inférieure dans le groupe traité par la nanosuspension comparativement aux autres groupes. La survie des souris était aussi supérieure. / Hypothesis : Nanomilling of a nystatin suspension will increase its antifungal efficacy in vitro and in vivo. Methods: A nystatin nanosuspension was obtained using wet bead milling. It was characterized for its particle size distribution and for its drug content. In vitro activity was evaluted against C. albicans strains SC5314 and LAM-1 at concentrations of 12.5 μg/mL up to 5000 μg/mL. The in vivo efficacy was evaluated using a murine model of oropharyngeal candidiasis. Results: Median particle size of the nystatin nanosuspension was reduced from 6577 nm to 137 nm. HPLC analysis demonstrated a content assay of 98.7 ± 0.8%. In vitro activity of the nanosuspension was superior to the suspension’s at concentrations ranging from 100 μg/mL to 5000 μg/mL. Oral fungal burdens were inferor in the nanosuspension group compared to the suspension and saline groups. Mice survival was also superior in the nanosuspension group.

Hypothèse : Le nanobroyage d'une suspension de nystatine augmentera son efficacité antifongique in vitro et in vivo. Méthode : Une nanosupension de nystatine a été obtenue en utilisant le broyage humide. Elle a été caractérisée pour sa distribution de taille des particules et pour sa teneur en principe actif. L'activité in vitro a été évaluée contre les souches de C. albicans SC5314 et LAM-1 aux concentrations 12.5 μg/mL jusqu'à 5000 μg/mL. L'efficacité in vivo a été évaluée en utilisant un modèle murin de candidose oropharyngée. Résultats : La taille médiane des particules de la nanosuspension de nystatine a été réduite de 6577 nm à 137 nm. L'analyse CLHP a demontré une teneur de 98.7 ± 0.8%. L'activité in vitro de la nanosuspension était supérieure à la suspension aux concentrations 100 μg/mL à 5000 μg/mL. La charge fongique orale était inférieure dans le groupe traité par la nanosuspension comparativement aux autres groupes. La survie des souris était aussi supérieure. / Hypothesis : Nanomilling of a nystatin suspension will increase its antifungal efficacy in vitro and in vivo. Methods: A nystatin nanosuspension was obtained using wet bead milling. It was characterized for its particle size distribution and for its drug content. In vitro activity was evaluted against C. albicans strains SC5314 and LAM-1 at concentrations of 12.5 μg/mL up to 5000 μg/mL. The in vivo efficacy was evaluated using a murine model of oropharyngeal candidiasis. Results: Median particle size of the nystatin nanosuspension was reduced from 6577 nm to 137 nm. HPLC analysis demonstrated a content assay of 98.7 ± 0.8%. In vitro activity of the nanosuspension was superior to the suspension’s at concentrations ranging from 100 μg/mL to 5000 μg/mL. Oral fungal burdens were inferor in the nanosuspension group compared to the suspension and saline groups. Mice survival was also superior in the nanosuspension group.