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Objectives: Objective: To undertake a pilot, feasibility RCT of umbilical cord blood derived cell therapy for treatment of adult patients infected with SARS-CoV-2 virus related moderate-to-severe pneumonia to prevent progression to severe ARDS. Hypothesis: Expanded cord blood derived cell therapy will be feasible, well tolerated and show potential efficacy in the treatment of acute COVID-19 related moderate to severe pneumonia in adult patients because of their powerful anti-inflammatory and immunomodulatory properties. Trial design: Pilot, parallel design randomised controlled trial. Participant(s): The trial will recruit 24 hospitalised patients with confirmed SARS-CoV-2 infection and pneumonia from July to December 2020 at Monash Medical Centre in Melbourne, Australia. Intervention and comparator: Intervention: Intravenous injection of expanded umbilical cord blood cells at a dose of 5 million cells/kg (maximum dose - 500 million cells). Cell infusion will occur over 30-60 minutes through a peripheral intravenous cannula. Standard supportive care will continue as needed. Comparator: Standard supportive care. Main outcomes: Safety and tolerability of cell administration within first 24 hours of administration; clinical improvement on a seven-category clinical improvement ordinal scale. Randomisation: Randomisation will be done using computer generated allocation to intervention/ control groups in a 1:1 ratio (in blocks of 6) using sealed opaque envelopes. Blinding (masking): This will be an unblinded study, given that it is the first study using expanded cord blood cells in COVID-19 patients. There will be no placebo infusion. Numbers to be randomised (sample size): Twelve participants in each group. Total n=24. Trial Status: CBC-19 protocol v2, dated 23rd April 2020. Recruitment has not started yet. Estimated recruitment timeline is between 1st July - 31st December 2020. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12620000478910, reg

In vitro models recapitulate tissue-specific microenvironments of the human body in an experimental setting to study cell functions and responses in a holistic approach and to develop improved therapeutics. The hematopoietic stem cell (HSC) niche is located in the bone marrow in two main compartments: the endosteal niche, next to the inner face of the bone, and the perivascular niche, next to bone marrow sinusoids. Current in vitro models of the HSC niche introduce elements of only one of these two compartments. Tissue engineering strategies can advance our understanding of the HSC niche and current treatments of blood-related diseases. Herein, we describe a novel multiphasic tissue-engineered construct that incorporates elements of both compartments. To recreate the endosteal niche, primary human osteoblasts are grown on medical grade polycaprolactone scaffolds produced by melt electrospinning under osteogenic conditions to allow the deposition of a dense bone matrix. To recreate the perivascular niche, human umbilical vein endothelial cells and placenta-derived mesenchymal stem cells are embedded in star-shaped polyethylene glycol-heparin-based hydrogels to allow the formation of capillary-like networks. The multiphasic tissue-engineering construct is built by aligning the bone matrix with the capillary-like networks to enable the short-term culture and expansion of CD34+ cells. To our knowledge, this is the first in vitro model of the HSC niche that aligns elements of both the endosteal and the perivascular niche in a single culture system.

Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80°C and boiled in dimethylformamide (153°C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules.

Stem cells (SC) are among the most promising cell sources for tissue engineering due to their ability to self-renew and differentiate, properties that underpin their clinical application in tissue regeneration. As such, control of SC fate is one of the most crucial issues that needs to be fully understood to realise their tremendous potential in regenerative biology. The use of functionalized nanostructured materials (NM) to control the microscale regulation of SC has offered a number of new features and opportunities for regulating SC. However, fabricating and modifying such NM to induce specific SC response still represent a significant scientific and technological challenge. Due to their versatility, plasmas are particularly attractive for the manufacturing and modification of tailored nanostructured surfaces for stem cell control. In this review, we briefly describe the biological role of SC and the mechanisms by which they are controlled and then highlight the benefits of using a range of nanomaterials to control the fate of SC. We then discuss how plasma nanoscience research can help produce/functionalise these NMs for more effective and specific interaction with SCs. The review concludes with a perspective on the advantages and challenges of research at the intersection between plasma physics, materials science, nanoscience, and SC biology.

A large body of evidence suggests hemopoietic stem cells (HSCs) exist in an endosteal niche close to bone, whereas others suggest that the HSC niche is intimately associated with vasculature. In this study, we show that transplanted hemopoietic stem and progenitor cells (HSPCs) home preferentially to the trabecular-rich metaphysis of the femurs in nonablated mice at all time points from 15 minutes to 15 hours after transplantation. Within this region, they exist in an endosteal niche in close association with blood vessels. The preferential homing of HSPCs to the metaphysis occurs rapidly after transplantation, suggesting that blood vessels within this region may express a unique repertoire of endothelial adhesive molecules. One candidate is hyaluronan (HA), which is highly expressed on the blood vessel endothelium in the metaphysis. Analysis of the early stages of homing and the spatial distribution of transplanted HSPCs at the single-cell level in mice devoid of Has3-synthesized HA, provides evidence for a previously undescribed role for HA expressed on endothelial cells in directing the homing of HSPCs to the metaphysis. © 2011 by The American Society of Hematology.

Background. The mechanisms responsible for the maintenance of pluripotency in human embryonic stem cells, and those that drive their commitment into particular differentiation lineages, are poorly understood. In fact, even our knowledge of the phenotype of hESC is limited, because the immunological and molecular criteria presently used to define this phenotype describe the properties of a heterogeneous population of cells. Results. We used a novel approach combining immunological and transcriptional analysis (immunotranscriptional profiling) to compare gene expression in hESC populations at very early stages of differentiation. Immunotranscriptional profiling enabled us to identify novel markers of stem cells and their differentiated progeny, as well as novel potential regulators of hESC commitment and differentiation. The data show clearly that genes associated with the pluripotent state are downregulated in a coordinated fashion, and that they are co-expressed with lineage specific transcription factors in a continuum during the early stages of stem cell differentiation. Conclusion. These findings, that show that maintenance of pluripotency and lineage commitment are dynamic, interactive processes in hESC cultures, have important practical implications for propagation and directed differentiation of these cells, and for the interpretation of mechanistic studies of hESC renewal and commitment. Since embryonic stem cells at defined stages of commitment can be isolated in large numbers by immunological means, they provide a powerful model for studying molecular genetics of stem cell commitment in the embryo. © 2007 Laslett et al; licensee BioMed Central Ltd.

BACKGROUND: The mechanisms responsible for the maintenance of pluripotency in human embryonic stem cells, and those that drive their commitment into particular differentiation lineages, are poorly understood. In fact, even our knowledge of the phenotype of hESC is limited, because the immunological and molecular criteria presently used to define this phenotype describe the properties of a heterogeneous population of cells. RESULTS: We used a novel approach combining immunological and transcriptional analysis (immunotranscriptional profiling) to compare gene expression in hESC populations at very early stages of differentiation. Immunotranscriptional profiling enabled us to identify novel markers of stem cells and their differentiated progeny, as well as novel potential regulators of hESC commitment and differentiation. The data show clearly that genes associated with the pluripotent state are downregulated in a coordinated fashion, and that they are co-expressed with lineage specific transcription factors in a continuum during the early stages of stem cell differentiation. CONCLUSION: These findings, that show that maintenance of pluripotency and lineage commitment are dynamic, interactive processes in hESC cultures, have important practical implications for propagation and directed differentiation of these cells, and for the interpretation of mechanistic studies of hESC renewal and commitment. Since embryonic stem cells at defined stages of commitment can be isolated in large numbers by immunological means, they provide a powerful model for studying molecular genetics of stem cell commitment in the embryo.

Background: Traditionally, following high-dose therapy (HDT), unmanipulated autologous PBPC are infused. Alternatively, purified CD34+ cells can now be obtained by immunomagnetic separation using the CliniMACS device. Limited data currently exist examining hemopoietic recovery with such cells. Method(s): Ten patients with advanced breast cancer had PBPC mobilized with docetaxel (100 mg/m2) and G-CSF (10 mug/kg per day), harvested and processed using the CliniMACS CD34-selection device and equally divided into three aliquots for cryopreservation. Unmanipulated 'back-up' cells were also collected on a separate day of the same mobilization, divided into three and cryopreserved. Patients subsequently received three cycles of HDT with cyclophosphamide (4 g/m2), thiotepa (300 mg/m2) and paclitaxel (175 mg/m2). The intent was for patients to receive CD34-selected cells to support each of the three cycles of HDT (i.e., 1/3 for each cycle). If, however, hemopoietic recovery was delayed after Cycle 1, 1/3 of the unmanipulated cells were infused following Cycle 2 and the remaining CD34-selected cells (2/3) were used to support Cycle 3. Result(s): PBPC from 10 patients underwent CD34-selection with a resulting median purity of 93% (range: 76-98%) and yield of 62% (range: 16-93%). Of the 10 patients, only two were able to be supported with CD34-selected cells for all three cycles of HDT. The remaining eight patients required unmanipulated 'back-up' cells to support Cycle 2. Three patients also required infusion of 'back-up' unmanipulated cells because of persistent neutropenia (n = 1) or thrombocytopenia (n = 2) following cycles initially supported by CD34-selected cells. The median number of CD34-selected cells (x 106/kg) infused per cycle was 1.5 (0.7-2.6) (n = 20) and unselected cells was 1.7 (1.4-2.8) (n = 10). Comparing hemopoietic recovery between cycles of HDT supported by CD34-selected (n = 20) and unmanipulated cells (n = 10) there was a significant slowing with the CD3

Background: We have previously reported that repeated cycles of high-dose therapy (HDT), can be supported by unmanipulated autologous PBPC. Here we investigate whether purified CD34+ cells, obtained by immunomagnetic separation using the Isolex 300i device, can support such therapy. Method(s): Twenty-nine consecutive patients with metastatic breast cancer had PBPC mobilized and harvested following chemotherapy and G-CSF (10 mug/kg per day). Patients with > 4.0 x 106/kg CD34+ cells in the apheresis product underwent CD34-selection using the Isolex 300i (v2.0) device. All cells collected were equally divided into three aliquots and cryopreserved. Patients who did not achieve this threshold had unmanipulated cells collected and stored. Patients subsequently received three cycles of HDT with paclitaxel (175 mg/m2), thiotepa (300 mg/m2) and either ifosfamide (10 g/m2) or cyclophosphamide (4 g/m2). It was intended for patients to receive CD34-selected cells to support each of the three cycles of HDT (i.e 1/3 for each cycle) and to compare hemopoietic recovery between patients receiving CD34-selected cells or unmanipulated cells. Result(s): Thirteen of the 29 patients (45%) did not mobilize sufficient CD34+ cells to undergo CD34-selection. The remaining 16 patients underwent CD34-selection with a median purity of 84.3% (range: 16.3-96.1%) and yield of 34% (range: 1-60%). Fifteen of these patients proceeded to HDT and 42 of the planned 45 cycles were administered. Nine patients had all three HDT cycles supported by CD34-selected cells. The median number of CD34-selected cells (x 106/kg) infused per cycle was 1.5 (range: 0.04-3.01). Three of the 15 patients required infusion of 'back-up' unmanipulated cells because of delayed neutrophil recovery. Of the 13 patients whose PBPCs did not undergo CD34+ cell selection, 11 proceeded to HDT with a median of 3.2 x 106/kg (range: 2.0-4.4) unselected cells infused per cycle and 31 of 33 planned cycles were delivered. When hemopoietic