In recent years, chimeric antigen receptor (CAR) modified T cells have been used as a treatment for haematological malignancies in several phase I and II trials and with Kymriah of Novartis and Yescarta of KITE Pharma, the first CAR T cell therapy products have been approved. Promising clinical outcomes have yet been tempered by the fact that many therapies may be prohibitively expensive to manufacture. The process is not yet defined, far from being standardised and often requires extensive manual handling steps.
View Article and Find Full Text PDFObjective: To develop a microwell suspension platform for the adaption of attached stem cell differentiation protocols into mixed suspension culture.
Results: We adapted an adherent protocol for the retinal differentiation of human induced pluripotent stem cells (hiPSCs) using a two-step protocol. Establishing the optimum embryoid body (EB) starting size and shaking speed resulted in the translation of the original adherent process into suspension culture.
Oxygen plays a key role in stem cell biology as a signaling molecule and as an indicator of cell energy metabolism. Quantification of cellular oxygen kinetics, i.e.
View Article and Find Full Text PDFThere is substantial evidence that cells produce a diverse response to changes in ECM stiffness depending on their identity. Our aim was to understand how stiffness impacts neuronal differentiation of embryonic stem cells (ESC's), and how this varies at three specific stages of the differentiation process. In this investigation, three effects of stiffness on cells were considered; attachment, expansion and phenotypic changes during differentiation.
View Article and Find Full Text PDFA major challenge facing the development of effective cell therapies is the efficient differentiation of pluripotent stem cells (PSCs) into pure populations. Lowering oxygen tension to physiological levels can affect both the expansion and differentiation stages. However, to date, there are no studies investigating the knock-on effect of culturing PSCs under low oxygen conditions on subsequent lineage commitment at ambient oxygen levels.
View Article and Find Full Text PDFAdherent cell lines are widely used across all fields of biology, including drug discovery, toxicity studies, and regenerative medicine. However, adherent cell processes are often limited by a lack of advances in cell culture systems. While suspension culture processes benefit from decades of development of instrumented bioreactors, adherent cultures are typically performed in static, noninstrumented flasks and well-plates.
View Article and Find Full Text PDFThe commercial use of stem cells continues to be constrained by the difficulty and high cost of developing efficient and reliable production protocols. The use of microfabricated systems combines good control over the cellular microenvironment with reduced use of resources in process optimization. Our previously reported microfabricated culture device was shown to be suitable for the culture of embryonic stem cells but required improvements to robustness, ease of use, and dissolved gas control.
View Article and Find Full Text PDFThe quantitative determination of key adherent cell culture characteristics such as confluency, morphology, and cell density is necessary for the evaluation of experimental outcomes and to provide a suitable basis for the establishment of robust cell culture protocols. Automated processing of images acquired using phase contrast microscopy (PCM), an imaging modality widely used for the visual inspection of adherent cell cultures, could enable the non-invasive determination of these characteristics. We present an image-processing approach that accurately detects cellular objects in PCM images through a combination of local contrast thresholding and post hoc correction of halo artifacts.
View Article and Find Full Text PDFWe present a multiplexed platform for a microfabricated stem cell culture device. The modular platform contains all the components to control stem cell culture conditions in an automated fashion. It does not require an incubator during perfusion culture and can be mounted on the stage of an inverted fluorescence microscope for high-frequency imaging of stem cell cultures.
View Article and Find Full Text PDFThe use of embryonic stem cells (ESCs) and their progeny in high throughput drug discovery and regenerative medicine will require production at scale of well characterized cells at an appropriate level of purity. The adoption of automated bioprocessing techniques offers the possibility to overcome the lack of consistency and high failure rates seen with current manual protocols. To build the case for increased use of automation this work addresses the key question: "can an automated system match the quality of a highly skilled and experienced person working manually?" To answer this we first describe an integrated automation platform designed for the 'hands-free' culture and differentiation of ESCs in microwell formats.
View Article and Find Full Text PDFUnlabelled: Automation and oxygen tension control are two tools that provide significant improvements to the reproducibility and efficiency of stem cell production processes.
Aim: the aim of this study was to establish a novel automation platform capable of controlling oxygen tension during both the cell-culture and liquid-handling steps of neural differentiation processes.
Materials & Methods: We built a bespoke automation platform, which enclosed a liquid-handling platform in a sterile, oxygen-controlled environment.
The capacity of milli and micro litre bioreactors to accelerate process development has been successfully demonstrated in traditional biotechnology. However, for regenerative medicine present smaller scale culture methods cannot cope with the wide range of processing variables that need to be evaluated. Existing microfabricated culture devices, which could test different culture variables with a minimum amount of resources (e.
View Article and Find Full Text PDFAim: Hypoxia is used within in vitro stem cell culture to recreate conditions similar to the in vivo environment surrounding the early blastocyst, from which embryonic stem cells can be isolated. Traditionally, basic research has used a coculture feeder system to culture pluripotent stem cells; however, it is possible that lowered oxygen may restrict cellular metabolic activity of the inactivated mouse embryonic fibroblasts (iMEFs) by disrupting oxygen-dependent pathways, such as ATP production through aerobic respiration. In this work, we examined the potential to continue using routine culture methods, such as iMEFs, to support human pluripotent cell expansion under hypoxia instead of feeder-free methods that can cause cell instability and offer a poor cell attachment rate.
View Article and Find Full Text PDFThe beneficial impact of lowering oxygen tension to physiological levels has been demonstrated in a number of stem cell differentiation protocols. The majority of these studies compare normal laboratory oxygen tension with one physiological condition (typically 2-5% O(2) ). In this article, we investigated whether the full spectrum of physiological oxygen tensions (0-20% O(2) ) and step-changes in oxygen tension could enhance the production of neural populations from of embryonic stem cells (ESCs).
View Article and Find Full Text PDFThe efficient differentiation of retinal cells from human pluripotent stem cells remains a major challenge for the development of successful and cost-effective cellular therapies for various forms of blindness. Current differentiation strategies rely on exposing pluripotent stem cells to soluble growth factors that play key roles during early development (such as DKK-1, Noggin, and IGF-1) at 20% oxygen (O(2)). This O(2) tension is, however, considerably higher than O(2) levels during organogenesis and may impair the differentiation process.
View Article and Find Full Text PDFDynamic mechanical properties of cells are becoming recognized as indicators and regulators of physiological processes such as differentiation, malignant phenotypes and mitosis. A key process in development and homeostasis is apoptosis and whilst the molecular control over this pathway is well studied, little is known about the mechanical consequences of cell death. Here, we study the caspase-dependent mechanical kinetics of single cells during early apoptosis initiated with the general protein-kinase inhibitor staurosporine.
View Article and Find Full Text PDFEmbryonic stem cells (ESC) are capable of proliferating indefinitely in vitro whilst retaining their ability to differentiate into cells of every adult lineage. Efficient, high yield processes, which direct differentiation of ESC to specific lineages, will underpin the development of cost-effective drug screening and cell therapy products. The aim of this study was to investigate whether laboratory oxygen tension currently used for the neuronal differentiation of ESC was suboptimal resulting in inefficient process yields.
View Article and Find Full Text PDFEmbryonic stem cells (ESC) have the developmental potential to form every adult cell type, even after prolonged culture. Reproducibly culturing pluripotent populations and directing differentiation has proven technically challenging yet will underpin the provision of stem cells for both screening and therapeutic applications. This study investigated whether the variations inherent in manual handling procedures cause inconsistent proliferation and phenotypic variability.
View Article and Find Full Text PDFThe cell membrane and cytoskeleton are dynamic structures that are strongly influenced by the thermo-mechanical background in addition to biologically driven mechanical processes. We used atomic force microscopy (AFM) to measure the local membrane motion of human foreskin fibroblasts (HFFs) which were found to be governed by random and non-random correlated mechanical processes. Interphase cells displayed distinct membrane pulsations in which the membrane was observed to slowly contract upwards followed by a recovery to its initial position.
View Article and Find Full Text PDFPrior work has reported that cotransfecting a gene of interest with the selectable marker neo can seriously perturb a number of cellular processes. In this study the influence of the neo gene on the growth, death, and metabolism of a murine myeloma NS0 cell line, expressing a chimeric antibody, was investigated. A pool of neo transfectants, 6A1-NEO, was selected with 500 microg/mL G418.
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