9 research outputs found
Assessing the insecticidal impact of rosemary essential oils on the saw-toothed grain beetle Oryzeaphilus surinamensis
This work studied the fumigant toxicity of free and encapsulated rosemary (Rosmarinus officinalis) essential oils against adults of the saw-toothed grain beetle (Oryzeaphilus surinamensis) for three storage periods: 30, 45 and 60 days. Chitosan was used as encapsulation matrix. GC/MS analysis results showed that camphor and 1,8-cineole were the major components with respectively 18.04% and 39.67%. Mortality rates caused by the essential oils at 300 ÎŒL/L air after 10 days of storage were about 85.48%. The median lethal concentration (LC50) was 124.80 ÎŒL/ L air. Encapsulation efficacy was 25.8% and loading capacity was 1.9%. Encapsulated essential oils achieved an efficacy of 82%, 100% and 100% respectively after 30, 45 and 60 days of storage. Reference treatment with Phosphine revealed a toxicity of 100%, 96% and 71% after 30, 45 and 60 days of storage respectively. Results showed that encapsulated essential oils caused a very slight modification on semolina properties. Protein contents decreased at the end of the storage period less than 1% (from 13.61% after 30 days to 12.91% after 60 days of storage). Encapsulated essential oils might be considered as an alternative fumigant control way for semolina without deterioration of its quality during storage
Improved cell therapy by transplantation of cellularized biomaterials in ischemic heart
La transplantation cellulaire apparaĂźt aujourdâhui comme une thĂ©rapie prometteuse pour certaines formes graves dâinsuffisance cardiaque rĂ©fractaire aux traitements classiques. Nous avons tentĂ© dans ce travail dâamĂ©liorer la thĂ©rapie cellulaire en agissant sur deux paramĂštres : la perte et la survie des cellules. Dans une premiĂšre Ă©tape, nous avons comparĂ© les effets de deux mĂ©thodes de couverture Ă©picardique des cellules via des biomatĂ©riaux cellularisĂ©s (feuilles de cellules et une matrice de gĂ©latine) par rapport Ă ceux des injections conventionnelles dans le myocarde. Nous avons choisi de transplanter des cellules souches musculaires pour une Ă©tude de preuve de concept. Une amĂ©lioration de la fonction contractile au bout de 1 mois associĂ©e Ă une amĂ©lioration de la rĂ©tention cellulaire, une augmentation du nombre de vaisseaux sanguins et une diminution du pourcentage de la fibrose ont Ă©tĂ© enregistrĂ©es dans les groupes de biomatĂ©riaux cellularisĂ©s par rapport au groupe des injections de cellules. Nous avons tentĂ© de confirmer les bĂ©nĂ©fices de la couverture Ă©picardique avec un autre type cellulaire. Nous avons choisi dâutiliser des cellules souches stromales dâorigine adipeuse (ADSC pour Adipose Derived Stroma/Stem Cells). Toutefois, et malgrĂ© les bĂ©nĂ©fices fonctionnels apportĂ©s lors des greffes, les feuilles dâADSC Ă©taient difficilement maniables lors de la chirurgie. De plus, les ADSC ont Ă©tĂ© incapables de gĂ©nĂ©rer de nouveaux cardiomyocytes sâintĂ©grant Ă©lectriquement et mĂ©caniquement dans le tissu receveur. Lâobjectif de « rĂ©gĂ©nĂ©ration » myocardique requiert lâapport de cellules ayant un potentiel de diffĂ©renciation cardiaque et devrait donc pouvoir ĂȘtre atteint avec des cellules souches embryonnaires (CSE). Nous avons choisi de travailler avec ce type cellulaire en raison de la possibilitĂ© de dĂ©river, Ă partir de ces cellules, de vĂ©ritables progĂ©niteurs des cardiomyocytes. Pour limiter les conditions hypoxiques de lâenvironnement ischĂ©mique, nous avons co-transplantĂ© les progĂ©niteurs cardiaques dĂ©rivĂ©s des CSE humaines avec des ADSC afin dâen exploiter les propriĂ©tĂ©s trophiques, et dâoptimiser ainsi la survie du greffon. Les deux populations cellulaires ont Ă©tĂ© transfĂ©rĂ©es sur le myocarde infarci via, une matrice de gĂ©latine (GELFILMâą) qui reprĂ©sente de meilleures propriĂ©tĂ©s mĂ©caniques. Lors de cette Ă©tude, nous avons remarquĂ© une prĂ©servation contre le remodelage ventriculaire Ă court (1mois) et long (6mois) terme chez les animaux greffĂ©s avec les patchs co-ensemencĂ©s par rapport aux animaux recevant le patch seul et lâĂ©tude des patchs composites a montrĂ© la prĂ©sence de cellules humaines in vitro mais pas in vivo, probablement Ă cause dâune maĂźtrise insuffisante du rejet. Notre travail a donc consistĂ© en une analyse systĂ©matique de plusieurs paramĂštres fondamentaux de thĂ©rapie cellulaire (mĂ©thode de transfert des cellules, limitation des conditions de mort cellulaire aprĂšs greffes, choix du type cellulaire). Les rĂ©sultats obtenus valident lâemploi des matrices cellularisĂ©es dĂ©posĂ©es sur lâĂ©picarde. Il convient maintenant dâoptimiser la nature du biomatĂ©riau, les conditions de culture des progĂ©niteurs cardiaques avec des cellules trophiques dans le but dâamĂ©liorer la survie du greffon.Cell transplantation has emerged as a promising therapy for some kind of severe heart failure refractory to conventional treatment. We have attempted in this work to improve cell therapy by acting on two parameters: the loss and cell survival. In a first step, we compared the effects of two methods of epicardial deposition of cells via natural biomaterials (Cell sheet and gelatin matrix) compared to conventional cells injections into the myocardium. We chose to transplant muscle stem cells for a proof of concept study. Improved contractile function after 1 month associated with improved cell retention, an increased number of blood vessels and a decrease in the percentage of fibrosis were recorded in the groups of cellularized biomaterials compared with injections group. We attempted to confirm the benefits of the epicardial cover with another cell type. We chose to use stromal stem cells from adipose origin as ADSC for Adipose Derived Stromal / Stem Cells. However, despite the functional benefits provided after transplantation, ADSC sheets were hardly manipulated during surgery. In addition, ADSC were unable to generate new cardiomyocytes electrically and mechanically integrated into the host tissue. The objective of "regeneration" requires the input of contractile cells with potential of cardiac differentiation that should be achieved with embryonic stem cells (ESC). We chose to work with this cell type because of the possibility of deriving of cardiac progenitor from these cells. To reduce the hypoxic conditions of the ischemic environment, we co-transplanted cardiac progenitor derived from human embryonic stem cells with ADSC in order to develop the trophic properties, and thus optimize the graft survival. Both cell populations were transferred to the infarcted myocardium using a gelatin matrix (GELFILM âą) which represents better mechanical properties than the cell sheet. In this study, we observed a significant functional preservation against negative ventricular remodeling in the short (1 month) and long (6 months) term in animals grafted with co-seeded patches compared to animals receiving only the patch. The study of composite patches showed the presence of human cells in vitro but not in vivo, probably because of inadequate control of rejection. Our work has involved a systematic analysis of several basic parameters of cell therapy (method of cell transfer, reduce of cell death after transplantation, choice of cell typeâŠ). The results validate the use of cellularized matrix deposited on the epicardium. In conclusion, to improve graft survival, it is necessary to optimize the nature of the biomaterial, the culture conditions of cardiac progenitor cells
AmĂ©lioration de la thĂ©rapie cellulaire par greffes de biomatĂ©riaux cellularisĂ©s dans un modĂšle dâischĂ©mie myocardique chez le rat
Cell transplantation has emerged as a promising therapy for some kind of severe heart failure refractory to conventional treatment. We have attempted in this work to improve cell therapy by acting on two parameters: the loss and cell survival. In a first step, we compared the effects of two methods of epicardial deposition of cells via natural biomaterials (Cell sheet and gelatin matrix) compared to conventional cells injections into the myocardium. We chose to transplant muscle stem cells for a proof of concept study. Improved contractile function after 1 month associated with improved cell retention, an increased number of blood vessels and a decrease in the percentage of fibrosis were recorded in the groups of cellularized biomaterials compared with injections group. We attempted to confirm the benefits of the epicardial cover with another cell type. We chose to use stromal stem cells from adipose origin as ADSC for Adipose Derived Stromal / Stem Cells. However, despite the functional benefits provided after transplantation, ADSC sheets were hardly manipulated during surgery. In addition, ADSC were unable to generate new cardiomyocytes electrically and mechanically integrated into the host tissue. The objective of "regeneration" requires the input of contractile cells with potential of cardiac differentiation that should be achieved with embryonic stem cells (ESC). We chose to work with this cell type because of the possibility of deriving of cardiac progenitor from these cells. To reduce the hypoxic conditions of the ischemic environment, we co-transplanted cardiac progenitor derived from human embryonic stem cells with ADSC in order to develop the trophic properties, and thus optimize the graft survival. Both cell populations were transferred to the infarcted myocardium using a gelatin matrix (GELFILM âą) which represents better mechanical properties than the cell sheet. In this study, we observed a significant functional preservation against negative ventricular remodeling in the short (1 month) and long (6 months) term in animals grafted with co-seeded patches compared to animals receiving only the patch. The study of composite patches showed the presence of human cells in vitro but not in vivo, probably because of inadequate control of rejection. Our work has involved a systematic analysis of several basic parameters of cell therapy (method of cell transfer, reduce of cell death after transplantation, choice of cell typeâŠ). The results validate the use of cellularized matrix deposited on the epicardium. In conclusion, to improve graft survival, it is necessary to optimize the nature of the biomaterial, the culture conditions of cardiac progenitor cells.La transplantation cellulaire apparaĂźt aujourdâhui comme une thĂ©rapie prometteuse pour certaines formes graves dâinsuffisance cardiaque rĂ©fractaire aux traitements classiques. Nous avons tentĂ© dans ce travail dâamĂ©liorer la thĂ©rapie cellulaire en agissant sur deux paramĂštres : la perte et la survie des cellules. Dans une premiĂšre Ă©tape, nous avons comparĂ© les effets de deux mĂ©thodes de couverture Ă©picardique des cellules via des biomatĂ©riaux cellularisĂ©s (feuilles de cellules et une matrice de gĂ©latine) par rapport Ă ceux des injections conventionnelles dans le myocarde. Nous avons choisi de transplanter des cellules souches musculaires pour une Ă©tude de preuve de concept. Une amĂ©lioration de la fonction contractile au bout de 1 mois associĂ©e Ă une amĂ©lioration de la rĂ©tention cellulaire, une augmentation du nombre de vaisseaux sanguins et une diminution du pourcentage de la fibrose ont Ă©tĂ© enregistrĂ©es dans les groupes de biomatĂ©riaux cellularisĂ©s par rapport au groupe des injections de cellules. Nous avons tentĂ© de confirmer les bĂ©nĂ©fices de la couverture Ă©picardique avec un autre type cellulaire. Nous avons choisi dâutiliser des cellules souches stromales dâorigine adipeuse (ADSC pour Adipose Derived Stroma/Stem Cells). Toutefois, et malgrĂ© les bĂ©nĂ©fices fonctionnels apportĂ©s lors des greffes, les feuilles dâADSC Ă©taient difficilement maniables lors de la chirurgie. De plus, les ADSC ont Ă©tĂ© incapables de gĂ©nĂ©rer de nouveaux cardiomyocytes sâintĂ©grant Ă©lectriquement et mĂ©caniquement dans le tissu receveur. Lâobjectif de « rĂ©gĂ©nĂ©ration » myocardique requiert lâapport de cellules ayant un potentiel de diffĂ©renciation cardiaque et devrait donc pouvoir ĂȘtre atteint avec des cellules souches embryonnaires (CSE). Nous avons choisi de travailler avec ce type cellulaire en raison de la possibilitĂ© de dĂ©river, Ă partir de ces cellules, de vĂ©ritables progĂ©niteurs des cardiomyocytes. Pour limiter les conditions hypoxiques de lâenvironnement ischĂ©mique, nous avons co-transplantĂ© les progĂ©niteurs cardiaques dĂ©rivĂ©s des CSE humaines avec des ADSC afin dâen exploiter les propriĂ©tĂ©s trophiques, et dâoptimiser ainsi la survie du greffon. Les deux populations cellulaires ont Ă©tĂ© transfĂ©rĂ©es sur le myocarde infarci via, une matrice de gĂ©latine (GELFILMâą) qui reprĂ©sente de meilleures propriĂ©tĂ©s mĂ©caniques. Lors de cette Ă©tude, nous avons remarquĂ© une prĂ©servation contre le remodelage ventriculaire Ă court (1mois) et long (6mois) terme chez les animaux greffĂ©s avec les patchs co-ensemencĂ©s par rapport aux animaux recevant le patch seul et lâĂ©tude des patchs composites a montrĂ© la prĂ©sence de cellules humaines in vitro mais pas in vivo, probablement Ă cause dâune maĂźtrise insuffisante du rejet. Notre travail a donc consistĂ© en une analyse systĂ©matique de plusieurs paramĂštres fondamentaux de thĂ©rapie cellulaire (mĂ©thode de transfert des cellules, limitation des conditions de mort cellulaire aprĂšs greffes, choix du type cellulaire). Les rĂ©sultats obtenus valident lâemploi des matrices cellularisĂ©es dĂ©posĂ©es sur lâĂ©picarde. Il convient maintenant dâoptimiser la nature du biomatĂ©riau, les conditions de culture des progĂ©niteurs cardiaques avec des cellules trophiques dans le but dâamĂ©liorer la survie du greffon
Amélioration de la thérapie cellulaire par greffes de biomatériaux cellularisés dans un modÚle d'ischémie myocardique chez le rat
La transplantation cellulaire apparaĂźt aujourd hui comme une thĂ©rapie prometteuse pour certaines formes graves d insuffisance cardiaque rĂ©fractaire aux traitements classiques. Nous avons tentĂ© dans ce travail d amĂ©liorer la thĂ©rapie cellulaire en agissant sur deux paramĂštres: la perte et la survie des cellules. Dans une premiĂšre Ă©tape, nous avons comparĂ© les effets de deux mĂ©thodes de couverture Ă©picardique des cellules via des biomatĂ©riaux cellularisĂ©s (feuilles de cellules et une matrice de gĂ©latine) par rapport Ă ceux des injections conventionnelles dans le myocarde. Nous avons choisi de transplanter des cellules souches musculaires pour une Ă©tude de preuve de concept. Une amĂ©lioration de la fonction contractile au bout de 1 mois associĂ©e Ă une amĂ©lioration de la rĂ©tention cellulaire, une augmentation du nombre de vaisseaux sanguins et une diminution du pourcentage de la fibrose ont Ă©tĂ© enregistrĂ©es dans les groupes de biomatĂ©riaux cellularisĂ©s par rapport au groupe des injections de cellules. Nous avons tentĂ© de confirmer les bĂ©nĂ©fices de la couverture Ă©picardique avec un autre type cellulaire. Nous avons choisi d utiliser des cellules souches stromales d origine adipeuse (ADSC pour Adipose Derived Stroma/Stem Cells). Toutefois, et malgrĂ© les bĂ©nĂ©fices fonctionnels apportĂ©s lors des greffes, les feuilles d ADSC Ă©taient difficilement maniables lors de la chirurgie. De plus, les ADSC ont Ă©tĂ© incapables de gĂ©nĂ©rer de nouveaux cardiomyocytes s intĂ©grant Ă©lectriquement et mĂ©caniquement dans le tissu receveur. L objectif de rĂ©gĂ©nĂ©ration myocardique requiert l apport de cellules ayant un potentiel de diffĂ©renciation cardiaque et devrait donc pouvoir ĂȘtre atteint avec des cellules souches embryonnaires (CSE). Nous avons choisi de travailler avec ce type cellulaire en raison de la possibilitĂ© de dĂ©river, Ă partir de ces cellules, de vĂ©ritables progĂ©niteurs des cardiomyocytes. Pour limiter les conditions hypoxiques de l environnement ischĂ©mique, nous avons co-transplantĂ© les progĂ©niteurs cardiaques dĂ©rivĂ©s des CSE humaines avec des ADSC afin d en exploiter les propriĂ©tĂ©s trophiques, et d optimiser ainsi la survie du greffon. Les deux populations cellulaires ont Ă©tĂ© transfĂ©rĂ©es sur le myocarde infarci via, une matrice de gĂ©latine (GELFILM ) qui reprĂ©sente de meilleures propriĂ©tĂ©s mĂ©caniques. Lors de cette Ă©tude, nous avons remarquĂ© une prĂ©servation contre le remodelage ventriculaire Ă court (1mois) et long (6mois) terme chez les animaux greffĂ©s avec les patchs co-ensemencĂ©s par rapport aux animaux recevant le patch seul et l Ă©tude des patchs composites a montrĂ© la prĂ©sence de cellules humaines in vitro mais pas in vivo, probablement Ă cause d une maĂźtrise insuffisante du rejet. Notre travail a donc consistĂ© en une analyse systĂ©matique de plusieurs paramĂštres fondamentaux de thĂ©rapie cellulaire (mĂ©thode de transfert des cellules, limitation des conditions de mort cellulaire aprĂšs greffes, choix du type cellulaire). Les rĂ©sultats obtenus valident l emploi des matrices cellularisĂ©es dĂ©posĂ©es sur l Ă©picarde. Il convient maintenant d optimiser la nature du biomatĂ©riau, les conditions de culture des progĂ©niteurs cardiaques avec des cellules trophiques dans le but d amĂ©liorer la survie du greffon.Cell transplantation has emerged as a promising therapy for some kind of severe heart failure refractory to conventional treatment. We have attempted in this work to improve cell therapy by acting on two parameters: the loss and cell survival. In a first step, we compared the effects of two methods of epicardial deposition of cells via natural biomaterials (Cell sheet and gelatin matrix) compared to conventional cells injections into the myocardium.We chose to transplant muscle stem cells for a proof of concept study.Improved contractile function after 1 month associated with improved cell retention, an increased number of blood vessels and a decrease in the percentage of fibrosis were recorded in the groups of cellularized biomaterials compared with injections group. We attempted to confirm the benefits of the epicardial cover with another cell type.We chose to use stromal stem cells from adipose origin as ADSC for Adipose Derived Stromal / Stem Cells.However, despite the functional benefits provided after transplantation, ADSC sheets were hardly manipulated during surgery.In addition, ADSC were unable to generate new cardiomyocytes electrically and mechanically integrated into the host tissue. The objective of "regeneration" requires the input of contractile cells with potential of cardiac differentiation that should be achieved with embryonic stem cells (ESC).We chose to work with this cell type because of the possibility of deriving of cardiac progenitor from these cells. To reduce the hypoxic conditions of the ischemic environment, we co-transplanted cardiac progenitor derived from human embryonic stem cells with ADSC in order to develop the trophic properties, and thus optimize the graft survival.Both cell populations were transferred to the infarcted myocardium using a gelatin matrix (GELFILM ) which represents better mechanical properties than the cell sheet. In this study, we observed a significant functional preservation against negative ventricular remodeling in the short (1 month) and long (6 months) term in animals grafted with co-seeded patches compared to animals receiving only the patch. The study of composite patchesshowed the presence of human cells in vitro but not in vivo, probably because of inadequate control of rejection. Our work has involved a systematic analysis of several basic parameters of cell therapy (method of cell transfer, reduce of cell death after transplantation, choice of cell type ).The results validate the use of cellularized matrix deposited on the epicardium. In conclusion, to improve graft survival,it is necessary to optimize the nature of the biomaterial, the culture conditions of cardiac progenitor cells.PARIS5-Bibliotheque electronique (751069902) / SudocSudocFranceF
Atrial fibrillation is associated with the fibrotic remodelling of adipose tissue in the subepicardium of human and sheep atria
International audienceAims: Accumulation of atrial adipose tissue is associated with atrial fibrillation (AF). However, the underlying mechanisms remain poorly understood. We examined the relationship between the characteristics of fatty infiltrates of the atrial myocardium and the history of AF.Methods and results: Atrial samples, collected in 92 patients during cardiac surgery and in a sheep model of persistent AF, were subjected to a detailed histological analysis. In sections of human right atrial samples, subepicardial fatty infiltrations were commonly observed in the majority of patients. A clear difference in the appearance and fibrotic content of these fatty infiltrations was observed. Fibro-fatty infiltrates predominated in patients with permanent AF (no AF: 37 ± 24% vs. paroxysmal AF: 50 ± 21% vs. permanent AF: 64 ± 23%, P < 0.001). An inverse correlation between fibrotic remodelling and the amount of subepicardial adipose tissue suggested the progressive fibrosis of fatty infiltrates with permanent AF. This hypothesis was tested in a sheep model of AF. In AF sheep, an increased accumulation of peri-atrial fat depot was observed on cardiac magnetic resonance imaging and dense fibro-fatty infiltrations predominated in the left atria of AF sheep. Cellular inflammation, mainly consisting of functional cytotoxic T lymphocytes, was observed together with adipocyte cell death in human atria.Conclusion: Atrial fibrillation is associated with the fibrosis of subepicardial fatty infiltrates, a process in which cytotoxic lymphocytes might be involved. This remodelling of the atrial subepicardium could contribute to structural remodelling forming a substrate for AF
Efficacy of Epicardially Delivered Adipose Stromal Cell Sheets in Dilated Cardiomyopathy
International audienceno abstrac
Efficacy of epicardially delivered adipose stroma cell sheets in dilated cardiomyopathy
International audienceFew studies have assessed the effects of cell therapy in non-ischaemic cardiomyopathies which, however, contribute to a large number of cardiac failures. Assuming that such conditions are best suited for a global delivery of cells, we assessed the effects of epicardially delivered adipose tissue-derived stroma cell (ADSC) sheets in a mouse model of dilated cardiomyopathy based on cardiac-specific and tamoxifen-inducible invalidation of serum response factor. Three weeks after tamoxifen administration, the function of the left ventricle (LV) was assessed by echocardiography. Twenty-nine mice were then allocated to control (n 9, non-transgenic), sham (n 10, transgenic non-treated), and treated (n 10, transgenic) groups. In the treated group, 3 10(6) allogeneic ADSCs were cultured for 2 days onto temperature-responsive polymers and the generated sheets were then transplanted over the surface of the heart. In 10 additional mice, the sheet was made of green fluorescent protein (GFP)-labelled ADSCs to track cell fate. Function, engraftment, and fibrosis were blindly assessed after 3 weeks. In the non-treated group, fractional shortening declined compared with baseline, whereas the sheet application resulted in its stabilization. This correlated with a lesser degree of LV remodelling, as LV end-diastolic and end-systolic diameters did not differ from baseline values. Many GFP cells were identified in the epicardial graft and in the myocardium. Treated animals also displayed a reduced expression of the stress-induced atrial natriuretic factor and beta-myosin heavy chain genes. These protective effects were also accompanied by a reduction of myocardial fibrosis. These results strongly suggest the functional relevance of epicardially delivered cell-seeded biomaterials to non-ischaemic heart failure
Long-Term Functional Benefits of Epicardial Patches as Cell Carriers
International audienceBoth enzymatic dissociation of cells prior to needle-based injections and poor vascularization of myocardial infarct areas are two important contributors to cell death and impede the efficacy of cardiac cell therapy. Because these limitations could be overcome by scaffolds ensuring cell cohesiveness and codelivery of angiogenic cells, we used a chronic rat model of myocardial infarction to assess the long-term (6 months) effects of the epicardial delivery of a composite collagen-based patch harboring both cardiomyogenesis-targeted human embryonic SSEA-1(+) (stem cell-derived stage-specific embryonic antigen-1 positive) cardiovascular progenitors and autologous (rat) adipose tissue-derived angiogenesis-targeted stromal cells (n=27). Cell-free patches served as controls (n=28). Serial follow-up echocardiographic measurements of left ventricular ejection fraction (LVEF) showed that the composite patch group yielded a significantly better preservation of left ventricular function that was sustained over time as compared with controls, and this pattern persisted when the assessment was restricted to the subgroup of rats with initial LVEFs below 50%. The composite patch group was also associated with significantly less fibrosis and more vessels in the infarct area. However, although human progenitors expressing cardiac markers were present in the patches before implantation, none of them could be subsequently identified in the grafted tissue. These data confirm the efficacy of epicardial scaffolds as cell carriers for ensuring long-term functional benefits and suggest that these effects are likely related to paracrine effects and call for optimizing cross-talks between codelivered cell populations to achieve the ultimate goal of myocardial regeneration