RESUMEN
The limited regenerative capacity of the heart after a myocardial infarct results in remodeling processes that can progress to congestive heart failure (CHF). Several strategies including mechanical stabilization of the weakened myocardium and regenerative approaches (specifically stem cell technologies) have evolved which aim to prevent CHF. However, their final performance remains limited motivating the need for an advanced strategy with enhanced efficacy and reduced deleterious effects. An epicardial carrier device enabling a targeted application of a biomaterial-based therapy to the infarcted ventricle wall could potentially overcome the therapy and application related issues. Such a device could play a synergistic role in heart regeneration, including the provision of mechanical support to the remodeling heart wall, as well as providing a suitable environment for in situ stem cell delivery potentially promoting heart regeneration. In this study, we have developed a novel, single-stage concept to support the weakened myocardial region post-MI by applying an elastic, biodegradable patch (SPREADS) via a minimal-invasive, closed chest intervention to the epicardial heart surface. We show a significant increase in %LVEF 14â¯days post-treatment when GS (clinical gold standard treatment) was compared to GSâ¯+â¯SPREADS + Gel with and without cells (pâ¯≤â¯0.001). Furthermore, we did not find a significant difference in infarct quality or blood vessel density between any of the groups which suggests that neither infarct quality nor vascularization is the mechanism of action of SPREADS. The SPREADS device could potentially be used to deliver a range of new or previously developed biomaterial hydrogels, a remarkable potential to overcome the translational hurdles associated with hydrogel delivery to the heart.
Asunto(s)
Implantes Absorbibles , Tratamiento Basado en Trasplante de Células y Tejidos/instrumentación , Hidrogeles/administración & dosificación , Células Madre Mesenquimatosas , Infarto del Miocardio/terapia , Tejido Adiposo/citología , Animales , Materiales Biocompatibles , Movimiento Celular/efectos de los fármacos , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Diseño de Equipo , Femenino , Humanos , Ácido Hialurónico , Hidrogeles/química , Hidrogeles/farmacología , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/efectos de los fármacos , Infarto del Miocardio/fisiopatología , Pericardio , Porcinos , ViscosidadRESUMEN
Injectable hydrogels that aim to mechanically stabilise the weakened left ventricle wall to restore cardiac function or to deliver stem cells in cardiac regenerative therapy have shown promising data. However, the clinical translation of hydrogel-based therapies has been limited due to difficulties injecting them through catheters. We have engineered a novel catheter, Advanced Materials Catheter (AMCath), that overcomes translational hurdles associated with delivering fast-gelling covalently cross-linked hyaluronic acid hydrogels to the myocardium. We developed an experimental technique to measure the force required to inject such hydrogels and determined the mechanical/viscoelastic properties of the resulting hydrogels. The preliminary in vivo feasibility of delivering fast-gelling hydrogels through AMCath was demonstrated by accessing the porcine left ventricle and showing that the hydrogel was retained in the myocardium post-injection (three 200 µL injections delivered, 192, 204 and 183 µL measured). However, the mechanical properties of the hydrogels were reduced by passage through AMCath (≤20.62% reduction). We have also shown AMCath can be used to deliver cardiopoietic adipose-derived stem cell-loaded hydrogels without compromising the viability (80% viability) of the cells in vitro. Therefore, we show that hydrogel/catheter compatibility issues can be overcome as we have demonstrated the minimally invasive delivery of a fast-gelling covalently cross-linked hydrogel to the beating myocardium.
Asunto(s)
Materiales Biocompatibles/administración & dosificación , Catéteres Cardíacos , Sistemas de Liberación de Medicamentos/instrumentación , Ácido Hialurónico/administración & dosificación , Hidrogeles/administración & dosificación , Animales , Línea Celular , Células Inmovilizadas/citología , Células Inmovilizadas/trasplante , Reactivos de Enlaces Cruzados/administración & dosificación , Diseño de Equipo , Humanos , Inyecciones , Infarto del Miocardio/terapia , Trasplante de Células Madre , Células Madre/citología , PorcinosRESUMEN
Polysaccharides meet several criteria for a suitable biomaterial for tissue engineering, which include biocompatibility and ability to support the delivery and growth of cells. Nevertheless, most of these polysaccharides, for example dextran, alginate, and glycosaminoglycans, are highly soluble in aqueous solutions. Hyaluronic acid hydrophobized by palmitic acid and processed to the form of wet-spun fibers and the warp-knitted textile scaffold is water non-soluble, but biodegradable material, which could be used for the tissue engineering purpose. However, its surface quality does not allow cell attachment. To enhance the biocompatibility the surface of palmitoyl-hyaluronan was roughened by freeze drying and treated by different cell adhesive proteins (fibronectin, fibrinogen, laminin, methacrylated gelatin and collagen IV). Except for collagen IV, these proteins covered the fibers uniformly for an extended period of time and supported the adhesion and cultivation of dermal fibroblasts and mesenchymal stem cells. Interestingly, adipose stem cells cultivated on the fibronectin-modified scaffold secreted increasing amount of HGF, SDF-1, and VEGF, three key growth factors involved in cardiac regeneration. These results suggested that palmitoyl-hyaluronan scaffold may be a promising material for various applications in tissue regeneration, including cardiac tissue repair. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1488-1499, 2018.
Asunto(s)
Materiales Biocompatibles/química , Ácido Hialurónico/química , Ácido Palmítico/química , Células Madre/citología , Andamios del Tejido/química , Adhesión Celular , Línea Celular , Proliferación Celular , Células Cultivadas , Fibronectinas/química , Humanos , Propiedades de Superficie , Ingeniería de TejidosRESUMEN
Chimeric Antigen Receptor (CAR) T cells expressing the fusion of the NKG2D protein with CD3ζ (NKG2D-CAR T Cells) acquire a specificity for stress-induced ligands expressed on hematological and solid cancers. However, these stress ligands are also transiently expressed by activated T cells implying that NKG2D-based T cells may undergo self-killing (fratricide) during cell manufacturing or during the freeze thaw cycle prior to infusion in patients. To avoid target-driven fratricide and enable the production of NKG2D-CAR T cells for clinical application, two distinct approaches were investigated. The first focused upon the inclusion of a Phosphoinositol-3-Kinase inhibitor (LY294002) into the production process. A second strategy involved the inclusion of antibody blockade of NKG2D itself. Both processes impacted T cell fratricide, albeit at different levels with the antibody process being the most effective in terms of cell yield. While both approaches generated comparable NKG2D-CAR T cells, there were subtle differences, for example in differentiation status, that were fine-tuned through the phasing of the inhibitor and antibody during culture in order to generate a highly potent NKG2D-CAR T cell product. By means of targeted inhibition of NKG2D expression or generic inhibition of enzyme function, target-driven CAR T fratricide can be overcome. These strategies have been incorporated into on-going clinical trials to enable a highly efficient and reproducible manufacturing process for NKG2D-CAR T cells.
Asunto(s)
Citotoxicidad Inmunológica/inmunología , Subfamilia K de Receptores Similares a Lectina de Células NK/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T/inmunología , Anticuerpos Bloqueadores/inmunología , Anticuerpos Bloqueadores/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cromonas/farmacología , Citotoxicidad Inmunológica/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Humanos , Inmunoterapia Adoptiva/métodos , Células K562 , Ligandos , Morfolinas/farmacología , Subfamilia K de Receptores Similares a Lectina de Células NK/antagonistas & inhibidores , Subfamilia K de Receptores Similares a Lectina de Células NK/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T/metabolismoRESUMEN
BACKGROUND: Regenerative cell-based therapies are associated with limited myocardial retention of delivered stem cells. The objective of this study is to develop an endocardial delivery system for enhanced cell retention. METHODS AND RESULTS: Stem cell retention was simulated in silico using 1- and 3-dimensional models of tissue distortion and compliance associated with delivery. Needle designs, predicted to be optimal, were accordingly engineered using nitinol, a nickel and titanium alloy displaying shape memory and superelasticity. Biocompatibility was tested with human mesenchymal stem cells. Experimental validation was performed with species-matched cells directly delivered into Langendorff-perfused porcine hearts or administered percutaneously into the endocardium of infarcted pigs. Cell retention was quantified by flow cytometry and real-time quantitative polymerase chain reaction methodology. Models, computing optimal distribution of distortion calibrated to favor tissue compliance, predicted that a 75°-curved needle featuring small-to-large graded side holes would ensure the highest cell retention profile. In isolated hearts, the nitinol curved needle catheter (C-Cath) design ensured 3-fold superior stem cell retention compared with a standard needle. In the setting of chronic infarction, percutaneous delivery of stem cells with C-Cath yielded a 37.7±7.1% versus 10.0±2.8% retention achieved with a traditional needle without effect on biocompatibility or safety. CONCLUSIONS: Modeling-guided development of a nitinol-based curved needle delivery system with incremental side holes achieved enhanced myocardial stem cell retention.
Asunto(s)
Sistemas de Liberación de Medicamentos/instrumentación , Sistemas de Liberación de Medicamentos/métodos , Endocardio/citología , Infarto del Miocardio/terapia , Trasplante de Células Madre , Células Madre/citología , Aleaciones , Animales , Tratamiento Basado en Trasplante de Células y Tejidos , Simulación por Computador , Modelos Animales de Enfermedad , Diseño de Equipo , Masculino , Infarto del Miocardio/patología , Agujas , Porcinos , Resultado del TratamientoRESUMEN
OBJECTIVE: Sarco-endoplasmic reticulum Ca(2+)-ATPase 2b (SERCA2b) and SERCA3 pump Ca(2+) in the endoplasmic reticulum (ER) of pancreatic ß-cells. We studied their role in the control of the free ER Ca(2+) concentration ([Ca(2+)](ER)) and the role of SERCA3 in the control of insulin secretion and ER stress. RESEARCH DESIGN AND METHODS: ß-Cell [Ca(2+)](ER) of SERCA3(+/+) and SERCA3(-/-) mice was monitored with an adenovirus encoding the low Ca(2+)-affinity sensor D4 addressed to the ER (D4ER) under the control of the insulin promoter. Free cytosolic Ca(2+) concentration ([Ca(2+)](c)) and [Ca(2+)](ER) were simultaneously recorded. Insulin secretion and mRNA levels of ER stress genes were studied. RESULTS: Glucose elicited synchronized [Ca(2+)](ER) and [Ca(2+)](c) oscillations. [Ca(2+)](ER) oscillations were smaller in SERCA3(-/-) than in SERCA3(+/+) ß-cells. Stimulating cell metabolism with various [glucose] in the presence of diazoxide induced a similar dose-dependent [Ca(2+)](ER) rise in SERCA3(+/+) and SERCA3(-/-) ß-cells. In a Ca(2+)-free medium, glucose moderately raised [Ca(2+)](ER) from a highly buffered cytosolic Ca(2+) pool. Increasing [Ca(2+)](c) with high [K] elicited a [Ca(2+)](ER) rise that was larger but more transient in SERCA3(+/+) than SERCA3(-/-) ß-cells because of the activation of a Ca(2+) release from the ER in SERCA3(+/+) ß-cells. Glucose-induced insulin release was larger in SERCA3(-/-) than SERCA3(+/+) islets. SERCA3 ablation did not induce ER stress. CONCLUSIONS: [Ca(2+)](c) and [Ca(2+)](ER) oscillate in phase in response to glucose. Upon [Ca(2+)](c) increase, Ca(2+) is taken up by SERCA2b and SERCA3. Strong Ca(2+) influx triggers a Ca(2+) release from the ER that depends on SERCA3. SERCA3 deficiency neither impairs Ca(2+) uptake by the ER upon cell metabolism acceleration and insulin release nor induces ER stress.