Culture expansion of adipose derived stromal cells. A closed automated Quantum Cell Expansion System compared with manual flask-based culture

Therapeutic application of adipose-derived stromal vascular fraction in myocardial infarction

The insufficiency of natural regeneration processes in higher organisms, including humans, underlies myocardial infarction (MI), which is one of the main causes of disability and mortality in the population of developed countries. The solution to this problem lies in the field of revealing the mechanisms of regeneration and creating on this basis new technologies for stimulating endogenous regenerative processes or replacing lost parts of tissues and organs with transplanted cells. Of great interest is the use of the so-called stromal vascular fraction (SVF), derived from autologous adipose tissue. It is known that the main functions of SVF are angiogenetic, antiapoptotic, antifibrotic, immune regulation, anti-inflammatory, and trophic. This study presents data on the possibility of using SVF, targeted regulation of its properties and reparative potential, as well as the results of research studies on its use for the restoration of damaged ischemic tissue after MI.

Comparative Analysis of Stromal Vascular Fraction and Alternative Mechanisms in Bone Fracture Stimulation to Bridge the Gap between Nature and Technological Advancement: A Systematic Review

BACKGROUND

Various stimulation methods, including electrical, ultrasound, mechanical, and biological interventions, are explored, each leveraging intricate cellular and molecular dynamics to expedite healing. The advent of stromal vascular fraction (SVF) marks a significant stride, offering multifarious benefits in bone healing, from enhanced bone formation to optimal vascular integration, drawing a harmonious balance between innate mechanisms and scientific advancements.

METHODS

This systematic review was conducted focusing on literature from 2016 to 2023 and encompassing various bone healing stimulation mechanisms like SVF, electrical, ultrasound, and mechanical stimulation. The extracted data underwent meticulous synthesis and analysis, emphasizing comparative evaluations of mechanisms, applications, and outcomes of each intervention.

RESULTS

The reviewed studies reveal the potential of SVF in bone fracture healing, with its regenerative and anti-inflammatory effects. The purification of SVF is crucial for safe therapeutic use. Characterization involves flow cytometry and microscopy. Studies show SVF's efficacy in bone regeneration, versatility in various contexts, and potential for clinical use. SVF appears superior to electrical, ultrasound, and mechanical stimulation, with low complications.

CONCLUSIONS

This review compares bone healing methods, including SVF. It provides valuable insights into SVF's potential for bone regeneration. However, due to limited human studies and potential bias, cautious interpretation is necessary. Further research is essential to validate these findings and determine the optimal SVF applications in bone healing.

An optimized HEK293T cell expansion protocol using a hollow-fiber bioreactor system

Viral vectors are commonly used to introduce genetic material into cells to modify cell function for a variety of purposes. Manufacture of those modified viruses may use a variety of cell types to generate high titers of viral particles; one of the most common being HEK293 cells. These cells have been modified into different lines aimed at satisfying specific use cases. HEK293T cells, for example, have been modified to include the SV40 large T antigen. Efficient viral particle production by HEK293T cells requires the maintenance of favorable cell culture conditions during expansion and transfection. This protocol describes the use of the Quantum® hollow-fiber bioreactor (HFB) system for the automated expansion of HEK293T cells, and the results derived using the protocol described herein were not compared with those from tissue culture flasks or other expansion platforms, as the parameters described are unique to Quantum's hollow fiber cell expansion environment. The purpose of this protocol is to help users of Quantum to focus on relevant parameters of expansion in the HFB milieu and to provide guidelines for a successful expansion of HEK293T cells in the Quantum system. The steps provided have been optimized to reliably control environmental factors related to glucose, lactate, and pH. Data reflecting this consistency are provided along with procedural time points reflected in text and figure formats.

A novel approach for large-scale manufacturing of small extracellular vesicles from bone marrow-derived mesenchymal stromal cells using a hollow fiber bioreactor

Mesenchymal stromal cells (MSCs) are promising therapeutic candidates in a variety of diseases due to having immunomodulatory and pro-regenerative properties. In recent years, MSC-derived small extracellular vesicles (sEVs) have attracted increasing interest as a possible alternative to conventional cell therapy. However, translational processes of sEVs for clinical applications are still impeded by inconsistencies regarding isolation procedures and culture conditions. We systematically compared different methods for sEV isolation from conditioned media of ex vivo expanded bone marrow-derived MSCs and demonstrated considerable variability of quantity, purity, and characteristics of sEV preparations obtained by these methods. The combination of cross flow filtration with ultracentrifugation for sEV isolation resulted in sEVs with similar properties as compared to isolation by differential centrifugation combined with ultracentrifugation, the latter is still considered as gold standard for sEV isolation. In contrast, sEV isolation by a combination of precipitation with polyethylene glycol and ultracentrifugation as well as cross flow filtration and size exclusion chromatography resulted in sEVs with different characteristics, as shown by surface antigen expression patterns. The MSC culture requires a growth-promoting supplement, such as platelet lysate, which contains sEVs itself. We demonstrated that MSC culture with EV-depleted platelet lysate does not alter MSC characteristics, and conditioned media of such MSC cultures provide sEV preparations enriched for MSC-derived sEVs. The results from the systematic stepwise evaluation of various aspects were combined with culture of MSCs in a hollow fiber bioreactor. This resulted in a strategy using cross flow filtration with subsequent ultracentrifugation for sEV isolation. In conclusion, this workflow provides a semi-automated, efficient, large-scale-applicable, and good manufacturing practice (GMP)-grade approach for the generation of sEVs for clinical use. The use of EV-depleted platelet lysate is an option to further increase the purity of MSC-derived sEVs.

Effect of allogeneic adipose tissue-derived mesenchymal stromal cell treatment in chronic ischaemic heart failure with reduced ejection fraction - the SCIENCE trial

AIMS

The aim of the SCIENCE trial was to investigate whether a single treatment with direct intramyocardial injections of adipose tissue-derived mesenchymal stromal cells (CSCC_ASCs) was safe and improved cardiac function in patients with chronic ischaemic heart failure with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

The study was a European multicentre, double-blind, placebo-controlled phase II trial using allogeneic CSCC_ASCs from healthy donors or placebo (2:1 randomization). Main inclusion criteria were New York Heart Association (NYHA) class II-III, left ventricular ejection fraction (LVEF) <45%, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels >300 pg/ml. CSCC_ASCs or placebo (isotonic saline) were injected directly into viable myocardium. The primary endpoint was change in left ventricular end-systolic volume (LVESV) at 6-month follow-up measured by echocardiography. A total of 133 symptomatic HFrEF patients were included. The treatment was safe without any drug-related severe adverse events or difference in cardiac-related adverse events during a 3-year follow-up period. There were no significant differences between groups during follow-up in LVESV (0.3 ± 5.0 ml, p = 0.945), nor in secondary endpoints of left ventricular end-diastolic volume (-2.0 ± 6.0 ml, p = 0.736) and LVEF (-1.6 ± 1.0%, p = 0.119). The NYHA class improved slightly within the first year in both groups without any difference between groups. There were no changes in 6-min walk test, NT-proBNP, C-reactive protein or quality of life the first year in any groups.

CONCLUSION

The SCIENCE trial demonstrated safety of intramyocardial allogeneic CSCC_ASC therapy in patients with chronic HFrEF. However, it was not possible to improve the pre-defined endpoints and induce restoration of cardiac function or clinical symptoms.

Danish phase II trial using adipose tissue derived mesenchymal stromal cells for patients with ischaemic heart failure

AIMS

Patients suffering from chronic ischaemic heart failure with reduced left ventricular ejection fraction (HFrEF) have reduced quality-of-life, repetitive hospital admissions, and reduced life expectancy. Allogeneic cell therapy is currently investigated as a potential treatment option after initially encouraging results from clinical autologous and allogeneic trials in patients with HFrEF. We aimed to investigate the allogeneic Cardiology Stem Cell Centre Adipose tissue derived mesenchymal Stromal Cell product (CSCC_ASC) as an add-on therapy in patients with chronic HFrEF.

METHODS AND RESULTS

This is a Danish multi-centre double-blinded placebo-controlled phase II study with direct intra-myocardial injections of allogeneic CSCC_ASC. A total of 81 HFrEF patients were included and randomized 2:1 to CSCC_ASC or placebo injections. The inclusion criteria were reduced left ventricular ejection fraction (LVEF ≤ 45%), New York Heart Association (NYHA) class II-III despite optimal anti-congestive heart failure medication and no further revascularization options. Injections of 0.3 mL CSCC_ASC (total cell dose 100 × 10⁶ ASCs) (n = 54) or isotonic saline (n = 27) were performed into the viable myocardium in the border zone of infarcted tissue using the NOGA Myostar® catheter (Biological Delivery System, Cordis, Johnson & Johnson, USA). The primary endpoint, left ventricular end systolic volume (LVESV), was evaluated at 6-month follow-up. The safety was measured during a 3-years follow-up period.

RESULTS

Mean age was 67.0 ± 9.0 years and 66.6 ± 8.1 years in the ASC and placebo groups, respectively. LVESV was unchanged from baseline to 6-month follow-up in the ASC (125.7 ± 68.8 mL and 126.3 ± 72.5 mL, P = 0.827) and placebo (134.6 ± 45.8 mL and 135.3 ± 49.6 mL, P = 0.855) group without any differences between the groups (0.0 mL (95% CI -9.1 to 9.0 mL, P = 0.992). Neither were there significant changes in left ventricular end diastolic volume or LVEF within the two groups or between groups -5.7 mL (95% CI -16.7 to 5.3 mL, P = 0.306) and -1.7% (95% CI -4.4. to 1.0, P = 0.212), respectively). NYHA classification and 6-min walk test did not alter significantly in the two groups (P > 0.05). The quality-of-life, total symptom, and overall summary score improved significantly only in the ASC group but not between groups. There were 24 serious adverse events (SAEs) in the ASC group and 11 SAEs in the placebo group without any significant differences between the two groups at 1-year follow-up. Kaplan-Meier plot using log-rank test of combined cardiac events showed an overall mean time to event of 30 ± 2 months in the ASC group and 29 ± 2 months in the placebo group without any differences between the groups during the 3 years follow-up period (P = 0.994).

CONCLUSIONS

Intramyocardial CSCC_ASC injections in patients with chronic HFrEF were safe but did not improve myocardial function or structure, nor clinical symptoms.

PPARβ/δ-Interfering Peptide Enhanced Mesenchymal Stromal Cell Immunoregulatory Properties

Background

Mesenchymal stem/stromal cells (MSCs) have been widely used for their therapeutic properties in many clinical applications including osteoarthritis. Despite promising preclinical results showing the ability of MSC to reduce the clinical severity of osteoarthritis (OA) in experimental animal models, the benefits of intra-articular injection of MSC in OA patients are limited to the short term. In this regard, it is anticipated that improving the properties of MSC may collectively enhance their long-term beneficial effects on OA.

Methods and Results

Recently, we have shown that PPARβ/δ inhibition using a commercially available antagonist in murine MSC increases their immunoregulatory potential in vitro as well as their therapeutic potential in an experimental murine arthritis model. Here, we relied on an innovative strategy to inhibit PPARβ/δ:NF-κB TF65 subunit interaction in human MSC by designing and synthesizing an interfering peptide, referred to PP11. Through RT-qPCR experiments, we evidenced that the newly synthesized PP11 peptide reduced the expression level of PDK4, a PPARβ/δ target gene, but did not modify the expression levels of ACOX1 and CPT1A, PPARα target genes, and FABP4, a PPARγ target gene compared with untreated human MSC. Moreover, we showed that human MSCs pretreated with PP11 exhibit a significantly higher capacity to inhibit the proliferation of activated PBMC and to decrease the frequency of M1-like macrophages.

Conclusions

We designed and synthesized an interfering peptide that potently and specifically blocks PPARβ/δ activity with concomitant enhancement of MSC immunoregulatory properties.

Optimizing an immunomodulatory potency assay for Mesenchymal Stromal Cell

The expeditious progress of Mesenchymal Stromal Cells (MSC) for therapeutic intervention calls for means to compare differences in potency of cell products. The differences may be attributed to innumerable sources including tissue origin, production methods, or even between batches. While the immunomodulatory potential of MSC is recognized and well-documented by an expansive body of evidence, the methodologies and findings vary markedly. In this study, we utilized flowcytometric analysis of lymphocyte proliferation based on cryopreserved peripheral blood mononuclear cells for quantification of the inhibitory effect of MSC. Technical aspects of fluorescent staining and cryopreservation of peripheral blood mononuclear cells were evaluated to obtain optimal results and increase feasibility. A range of common specific and unspecific mitogens was titrated to identify the conditions, in which the effects of Adipose tissue-derived Stromal Cells (ASC; a type of MSC) were most pronounced. Specific stimulation by antibody-mediated activation of CD3 and CD28 via TransAct and Dynabeads lead to substantial proliferation of lymphocytes, which was inhibited by ASC. These results were closely mirrored when applying unspecific stimulation in form of phytohemagglutinin (PHA), but not concanavalin A or pokeweed mitogen. The mixed lymphocyte reaction is a common assay which exploits alloreactivity between donors. While arguably more physiologic, the output of the assay often varies substantially, and the extent of proliferation is limited since the frequency of alloreactive cells is low, as opposed to the mitogens. To heighten the proliferative response and robustness, combinations of 2-5 donors were tested. Maximum proliferation was observed when combining 4 or more donors, which was efficiently suppressed by ASC. Several desirable and unfavorable traits can be attributed to the tested stimuli in the form of keywords. The importance of these traits should be scored on a laboratory-level to identify the ideal mitogen. In our case the ranking listed PHA as the most suited candidate. Developing robust assays is no trivial feat. By disclosing the full methodological framework in the present study, we hope to aid others in establishing functional metrics on the road to potency assays.

Polymerized Laminin-521: A Feasible Substrate for Expanding Induced Pluripotent Stem Cells at a Low Protein Concentration

Laminins (LNs) play a central role in the self-assembly and maintenance of basement membranes and are involved in critical interactions between cells and other extracellular matrix (ECM) proteins. Among the defined, xeno-free ECM culture matrices, LNs-namely LN521-have emerged as promising coating systems for the large-scale expansion of induced pluripotent stem cells (iPSCs). The biologic activity of LNs is enhanced by their acidification-induced self-polymerization into a cell-associated network called polylaminin (polyLN), which can recapitulate the native-like polymeric array in a cell-free system. Here, we show for the first time to our knowledge that polyLN521 displays a native-like hexagonal-like structure and that, at basal and low concentrations, it permits the large-scale expansion of human iPSCs. Human iPSCs expanded with polyLN521 maintained the pluripotent state and showed no impairment of karyotype stability or telomere length. These results suggest that low-concentration polyLN521 is a stable and cost-effective coating for large-scale iPSC expansion.

Membrane Applications in Autologous Cell Therapy

Stem cell and cell therapies, particularly autologous cell therapies, are becoming a common practice. However, in order for these technologies to achieve wide-scale clinical application, the prohibitively high cost associated with these therapies must be addressed through creative engineering. Membranes can be a disruptive technology to reshape the bioprocessing and manufacture of cellular products and significantly reduce the cost of autologous cell therapies. Examples of successful membrane applications include expansions of CAR-T cells, various human stem cells, and production of extracellular vesicles (EVs) using hollow fibre membrane bioreactors. Novel membranes with tailored functions and surface properties and novel membrane modules that can accommodate the changing needs for surface area and transport properties are to be developed to fulfil this key role.

Functional in vitro models of the inhibitory effect of adipose tissue-derived stromal cells on lymphocyte proliferation: Improved sensitivity and quantification through flow cytometric analysis

As the interest in cell-based therapies continue to increase, so does the need for assays detailing potency and providing platforms for identifying mechanisms of action. For most clinical implications of mesenchymal stromal cells, the immunomodulatory effect is crucial. While the suppressive potential on lymphocyte proliferation is well-described in literature, reproducible and standardized assays to document and quantify it varies from research group to research group and between methodologies. The aim of the present study was to utilize flowcytometry to quantify proliferation and identify measurements to increase the assay sensitivity to treatment with adipose tissue-derived stromal cells (ASC). Lymphocyte proliferation was induced by the unspecific mitogen phytohemagglutinin or by alloreactivity towards an irradiated donor in a mixed lymphocyte reaction. Addition of ASC did not change the composition of T cells, B cells, NK cells, NKT cell types considerably; likewise, no increases in proliferation were observed upon inclusion of ASC, demonstrating that ASC does not evoke an additive response. On the contrary, the suppressive effect of ASC was documented. By applying different gating strategies and curve fitting, the sensitivity was increased, and dose-response relationships established. Flow cytometric evaluation allows for more detailed identification of the lymphocytes affected by ASC and constitute a significant asset in future unraveling of modes and mechanisms of action, as well as quantification of potency.

Stromal Vascular Fraction for Knee Osteoarthritis - An Update

Orthobiologics never cease to cause popularity within the medical science field, distinctly in regenerative medicine. Recently, adipose tissue has been an object of interest for many researchers and medical experts due to the fact that it represents a novel and potential cell source for tissue engineering and regenerative medicine purposes. Stromal vascular fraction (SVF), for instance, which is an adipose tissue-derivative, has generated optimistic results in many scenarios. Its biological potential can be harnessed and administered into injured tissues, particularly areas in which standard healing is disrupted. This is a typical feature of osteoarthritis (OA), a common degenerative joint disease which is outlined by persistent inflammation and destruction of surrounding tissues. SVF is known to carry a large amount of stem and progenitor cells, which are able to perform self-renewal, differentiation, and proliferation. Furthermore, they also secrete several cytokines and several growth factors, effectively sustaining immune modulatory effects and halting the escalated pro-inflammatory status of OA. Although SVF has shown interesting results throughout the medical community, additional research is still highly desirable in order to further elucidate its potential regarding musculoskeletal disorders, especially OA.

GMP Compliant Production of a Cryopreserved Adipose-Derived Stromal Cell Product for Feasible and Allogeneic Clinical Use

The emerging field of advanced therapy medicinal products (ATMP) holds promise of treating a variety of diseases. Adipose-derived stromal cells (ASCs) are currently being marketed or tested as cell-based therapies in numerous clinical trials. To ensure safety and efficacy of treatments, high-quality products must be manufactured. A good manufacturing practice (GMP) compliant and consistent manufacturing process including validated quality control methods is critical. Product design and formulation are equally important to ensure clinical feasibility. Here, we present a GMP-compliant, xeno-free, and semiautomated manufacturing process and quality controls, used for large-scale production of a cryopreserved off-the-shelf ASC product and tested in several phase I and II allogeneic clinical applications.

Physiologic isolation and expansion of human mesenchymal stem/stromal cells for manufacturing of cell‐based therapy products

The utilization of mesenchymal stem/stromal cells raises new hopes in treatment of diseases and pathological conditions, while at the same time bringing immense challenges for researchers, manufacturers and physicians. It is essential to consider all steps along the in vitro fabrication of cell‐based products in order to reach efficient and reproducible treatment outcomes. Here, the optimal protocols for isolation, cultivation and differentiation of mesenchymal stem cells are required. In this review we discuss these aspects and their influence on the final cell‐based product quality. We demonstrate that physiological in vitro cell cultivation conditions play a crucial role in therapeutic functionalities of cultivated cells. We show that three‐dimensional cell culture, dynamic culture conditions and physiologically relevant in vitro oxygen concentrations during isolation and expansion make a decisive contribution towards the improvement of cell‐based products in regenerative medicine.

Culture Substrates for Improved Manufacture of Mesenchymal Stromal Cell Therapies

Recent developments in mesenchymal stromal cell (MSC) therapies have increased the demand for tools to improve their manufacture, including the selection of optimal culture substrate materials. While many clinical manufacturers use planar tissue culture plastic (TCP) surfaces for MSC production, others have begun exploring the use of alternative culture substrates that present a variety of spatial, mechanical, and biochemical cues that influence cell expansion and resulting cell quality. In this review, the effects of culture and material properties distinct from traditional planar TCP surfaces on MSC proliferation, surface marker expression, and commonly used indications for therapeutic potency are examined. The different properties summarized include the use of alternative culture formats such as cellular aggregates or 3D scaffolds, as well as the effects of culture substrate stiffness and presentation of specific adhesive ligands and topographical cues. Specific substrate properties can be related to greater cell expansion and improvement in specific therapeutic functionalities, demonstrating the utility of culture materials in further improving the clinical-scale manufacture of highly secretory MSC products.

Single-Use Bioreactors for Human Pluripotent and Adult Stem Cells: Towards Regenerative Medicine Applications

Research on human stem cells, such as pluripotent stem cells and mesenchymal stromal cells, has shown much promise in their use for regenerative medicine approaches. However, their use in patients requires large-scale expansion systems while maintaining the quality of the cells. Due to their characteristics, bioreactors have been regarded as ideal platforms to harbour stem cell biomanufacturing at a large scale. Specifically, single-use bioreactors have been recommended by regulatory agencies due to reducing the risk of product contamination, and many different systems have already been developed. This review describes single-use bioreactor platforms which have been used for human stem cell expansion and differentiation, along with their comparison with reusable systems in the development of a stem cell bioprocess for clinical applications.

Cellular Agriculture: Opportunities and Challenges

Cellular agriculture is the controlled and sustainable manufacture of agricultural products with cells and tissues without plant or animal involvement. Today, microorganisms cultivated in bioreactors already produce egg and milk proteins, sweeteners, and flavors for human nutrition as well as leather and fibers for shoes, bags, and textiles. Furthermore, plant cell and tissue cultures provide ingredients that stimulate the immune system and improve skin texture, with another precommercial cellular agriculture product, in vitro meat, currently receiving a great deal of attention. All these approaches could assist traditional agriculture in continuing to provide for the dietary requirements of a growing world population while freeing up important resources such as arable land. Despite early successes, challenges remain and are discussed in this review, with a focus on production processes involving plant and animal cell and tissue cultures.

Overview of current adipose-derived stem cell (ADSCs) processing involved in therapeutic advancements: flow chart and regulation updates before and after COVID-19

Adipose-derived stem cells (ADSCs) have raised big interest in therapeutic applications in regenerative medicine and appear to fulfill the criteria for a successful cell therapy. Their low immunogenicity and their ability to self-renew, to differentiate into different tissue-specific progenitors, to migrate into damaged sites, and to act through autocrine and paracrine pathways have been altogether testified as the main mechanisms whereby cell repair and regeneration occur. The absence of standardization protocols in cell management within laboratories or facilities added to the new technologies improved at patient's bedside and the discrepancies in cell outcomes and engraftment increase the limitations on their widespread use by balancing their real benefit versus the patient safety and security. Also, comparisons across pooled patients are particularly difficult in the fact that multiple medical devices are used and there is absence of harmonized assessment assays despite meeting regulations agencies and efficient GMP protocols. Moreover, the emergence of the COVID-19 breakdown added to the complexity of implementing standardization. Cell- and tissue-based therapies are completely dependent on the biological manifestations and parameters associated to and induced by this virus where the scope is still unknown. The initial flow chart identified for stem cell therapies should be reformulated and updated to overcome patient infection and avoid significant variability, thus enabling more patient safety and therapeutic efficiency. The aim of this work is to highlight the major guidelines and differences in ADSC processing meeting the current good manufacturing practices (cGMP) and the cellular therapy-related policies. Specific insights on standardization of ADSCs proceeding at different check points are also presented as a setup for the cord blood and bone marrow.

Adipose Tissue-Derived Stromal Cells Induce a Highly Trophic Environment While Reducing Maturation of Monocyte-Derived Dendritic Cells

Allogeneic cell-based therapies using adipose tissue-derived stromal cells (ASCs) offer an off-the-shelf alternative to autologous therapy. An underlying assumption is that ASC can modulate the immune response of the recipient. However, in vitro models are required to explore and identify cell interactions and mechanisms of action, to ensure sufficient and sustained effects, and to document these. In this study, we shed light on the effect of ASC manufactured for clinical use on monocyte-derived dendritic cells and an inflammatory microenvironment. ASCs were isolated from healthy voluntary donors, expanded using a human platelet lysate in bioreactors, and cryopreserved as per clinical use. Monocyte-derived dendritic cells were generated by isolation of monocytes and differentiation with GM-CSF and IL-4. Dendritic cells were cocultured with different ratios of ASC and matured with LPS and IFN-γ. Dexamethasone was included as an immunosuppressive control. Dendritic cells were analyzed by flow cytometry for CD11c, CD40, CD80, CD83, CD86, PD-L1, and HLA-DR, and supernatants were analyzed for FGF2, HGF, IL-10, IL-12p70, LIF, MIF, PDGF, PlGF, and IDO. Reduced expression of maturation markers was observed on ASC-treated dendritic cells, while high levels of PD-L1 were maintained. Interestingly, the expression of CD83 was elevated. Escalating ratios of ASC did not affect the concentration of IL-10 considerably, whereas the presence of IL-12 was reduced in a dose-dependent manner. Besides offsetting the IL-12/IL-10 balance, the concentrations of IDO and MIF were elevated in cocultures. Concentrations of FGF2, HGF, LIF, and PIGF were high in ASC cocultures, whereas PDGF was depleted. In a robust coculture model, the addition of ASC to dendritic cells inhibited the dendritic maturation substantially, while inducing a less inflammatory and more tolerogenic milieu. Despite the exposure to dendritic cells and inflammatory stimuli, ASC resulted in supernatants with trophic factors relevant for regeneration. Thus, ASC can perform immunomodulation while providing a regenerative environment.

Insights into the use of mesenchymal stem cells in COVID-19 mediated acute respiratory failure

The emergence of severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) at the end of 2019 in Hubei province China, is now the cause of a global pandemic present in over 150 countries. COVID-19 is a respiratory illness with most subjects presenting with fever, cough and shortness of breath. In a subset of patients, COVID-19 progresses to hypoxic respiratory failure and acute respiratory distress syndrome (ARDS), both of which are mediated by widespread inflammation and a dysregulated immune response. Mesenchymal stem cells (MSCs), multipotent stromal cells that mediate immunomodulation and regeneration, could be of potential benefit to a subset of COVID-19 subjects with acute respiratory failure. In this review, we discuss key features of the current COVID-19 outbreak, and the rationale for MSC-based therapy in this setting, as well as the limitations associated with this therapeutic approach.

Umbilical Cord-Derived Mesenchymal Stem Cells Are Able to Use bFGF Treatment and Represent a Superb Tool for Immunosuppressive Clinical Applications

Mesenchymal stem cells (MSCs) have become a promising tool in cellular therapy for restoring immune system haemostasis; however, the success of clinical trials has been impaired by the lack of standardized manufacturing processes. This study aims to determine the suitability of source tissues and culture media for the production of MSC-based advanced therapy medicinal products (ATMPs) and to define parameters to extend the set of release criteria. MSCs were isolated from umbilical cord (UC), bone marrow and lipoaspirate and expanded in three different culture media. MSC phenotype, proliferation capacity and immunosuppressive parameters were evaluated in normal MSCs compared to primed MSCs treated with cytokines mimicking an inflammatory environment. Compared to bone marrow and lipoaspirate, UC-derived MSCs (UC-MSCs) showed the highest proliferative capacity, which was further enhanced by media supplemented with bFGF, while the cells maintained their immunosuppressive characteristics. Moreover, UC-MSCs expanded in the bFGF-enriched medium were the least sensitive to undesirable priming-induced changes in the MSC phenotype. Surface markers and secreted factors were identified to reflect the cell response to inflammatory priming and to be variable among MSCs from different source tissues. This study demonstrates that UC is a favorable cell source for manufacturing MSC-based ATMPs for immunosuppressive applications. UC-MSCs are able to use the bFGF-enriched medium for higher cell yields without the impairment of immunosuppressive parameters and undesirable phenotype changes after inflammatory preconditioning of MSCs before transplantation. Additionally, immunosuppressive parameters were identified to help finding predictors of clinically efficient MSCs in the following clinical trials.

Autologous adipose-derived stromal cell treatment for patients with refractory angina (MyStromalCell Trial): 3-years follow-up results

Background

Stem cell therapy is investigated as a treatment option for patients with ischemic heart disease. In this study, long-term safety and efficacy of autologous intra-myocardial injections of adipose-derived stromal cells (ASCs) was studied in patients with refractory angina.

Methods

Sixty patients with coronary artery stenosis and preserved left ventricular ejection fraction were 2:1 randomised to intramyocardial injections of ASCs or saline and followed for 3 years.

Results

For patients in the ASC group, the bicycle exercise time and the exercise performance in watt were un-changed (383 ± 30 s to 370 ± 44 s, P = 0.052 and 81 ± 6 to 78 ± 10, P = 0.123, respectively), but the performance in METs was reduced significantly (4.2 ± 0.3 to 4.0 ± 0.4, P = 0.027) during the follow-up period. However, in the same period, there was in the placebo group a significant decline in bicycle exercise time (437 ± 53 s to 383 ± 58 s, P = 0.001), the exercise performance measured in watt (87 ± 12 W to 80 ± 12 W, P = 0.019) and in METs (4.5 ± 0.4 to 4.1 ± 0.4, P = 0.002). Moreover, angina measured as CCS class was significantly reduced in the ASC group but not in the placebo group (2.5 ± 0.9 to 1.8 ± 1.2, P = 0.002 and 2.5 ± 0.8 to 2.1 ± 1.3, P = 0.186, respectively). However, no significant change was observed between the two groups.

Conclusions

Patients receiving ASCs had improved cardiac symptoms and unchanged exercise capacity, in opposition to deterioration in the placebo group.

Trial registration ClinicalTrials.gov Identifier: NCT01449032. Registered 7 October 2011—Retrospectively registered, https://www.clinicaltrials.gov/ct2/show/NCT01449032?term=jens+kastrup&rank=7

Automation in cell and gene therapy manufacturing: from past to future

As more and more cell and gene therapies are being developed and with the increasing number of regulatory approvals being obtained, there is an emerging and pressing need for industrial translation. Process efficiency, associated cost drivers and regulatory requirements are issues that need to be addressed before industrialisation of cell and gene therapies can be established. Automation has the potential to address these issues and pave the way towards commercialisation and mass production as it has been the case for 'classical' production industries. This review provides an insight into how automation can help address the manufacturing issues arising from the development of large-scale manufacturing processes for modern cell and gene therapy. The existing automated technologies with applicability in cell and gene therapy manufacturing are summarized and evaluated here.

Large-scale expansion and characterization of CD3+ T-cells in the Quantum® Cell Expansion System

Background

The rapid evolution of cell-based immunotherapies such as chimeric antigen receptor T-cells for treatment of hematological cancers has precipitated the need for a platform to expand these cells ex vivo in a safe, efficient, and reproducible manner. In the Quantum^® Cell Expansion System (Quantum system) we evaluated the expansion of T-cells from healthy donors in a functionally-closed environment that reduces time and resources needed to produce a therapeutic dose.

Methods

Mononuclear cells from leukapheresis products from 5 healthy donors were activated with anti-CD3/CD28 Dynabeads^® and expanded in the Quantum system for 8–9 days using xeno-free, serum-free medium and IL-2. Harvested cells were phenotyped by flow cytometry and evaluated for cytokine secretion by multiplex assays.

Results

From starting products of 30 or 85 × 10⁶ mononuclear cells, CD3⁺ T-cell populations expanded over 500-fold following stimulation to provide yields up to 25 × 10⁹ cells within 8 days. T-cell yields from all donors were similar in terms of harvest numbers, viability and doubling times. Functionality (secretion of IFN-γ, IL-2 and TNF-α) was retained in harvested T-cells upon restimulation in vitro and T-cells displayed therapeutically-relevant less-differentiated phenotypes of naïve and central memory T-cells, with low expression of exhaustion markers LAG-3 and PD-1.

Conclusions

The Quantum system has been successfully used to produce large quantities of functional T-cells at clinical dosing scale and within a short timeframe. This platform could have wide applicability for autologous and allogeneic cellular immunotherapies for the treatment of cancer.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-2001-5) contains supplementary material, which is available to authorized users.

A comprehensive characterisation of large-scale expanded human bone marrow and umbilical cord mesenchymal stem cells. Stem Cell Res Ther. 2019;10:99. [PMID: 30885254 PMCID: PMC6421680 DOI: 10.1186/s13287-019-1202-4]

BACKGROUND

The manufacture of mesenchymal stem/stromal cells (MSCs) for clinical use needs to be cost effective, safe and scaled up. Current methods of expansion on tissue culture plastic are labour-intensive and involve several 'open' procedures. We have used the closed Quantum® hollow fibre bioreactor to expand four cultures each of MSCs derived from bone marrow (BM) and, for the first time, umbilical cords (UCs) and assessed extensive characterisation profiles for each, compared to parallel cultures grown on tissue culture plastic.

METHODS

Bone marrow aspirate was directly loaded into the Quantum®, and cells were harvested and characterised at passage (P) 0. Bone marrow cells were re-seeded into the Quantum®, harvested and further characterised at P1. UC-MSCs were isolated enzymatically and cultured once on tissue culture plastic, before loading cells into the Quantum®, harvesting and characterising at P1. Quantum®-derived cultures were phenotyped in terms of immunoprofile, tri-lineage differentiation, response to inflammatory stimulus and telomere length, as were parallel cultures expanded on tissue culture plastic.

RESULTS

Bone marrow cell harvests from the Quantum® were 23.1 ± 16.2 × 10⁶ in 14 ± 2 days (P0) and 131 ± 84 × 10⁶ BM-MSCs in 13 ± 1 days (P1), whereas UC-MSC harvests from the Quantum® were 168 ± 52 × 10⁶ UC-MSCs after 7 ± 2 days (P1). Quantum®- and tissue culture plastic-expanded cultures at P1 adhered to criteria for MSCs in terms of cell surface markers, multipotency and plastic adherence, whereas the integrins, CD29, CD49c and CD51/61, were found to be elevated on Quantum®-expanded BM-MSCs. Rapid culture expansion in the Quantum® did not cause shortened telomeres when compared to cultures on tissue culture plastic. Immunomodulatory gene expression was variable between donors but showed that all MSCs upregulated indoleamine 2, 3-dioxygenase (IDO).

CONCLUSIONS

The results presented here demonstrate that the Quantum® can be used to expand large numbers of MSCs from bone marrow and umbilical cord tissues for next-generation large-scale manufacturing, without impacting on many of the properties that are characteristic of MSCs or potentially therapeutic. Using the Quantum®, we can obtain multiple MSC doses from a single manufacturing run to treat many patients. Together, our findings support the development of cheaper cell-based treatments.

Rationale and design of the European multicentre study on Stem Cell therapy in IschEmic Non-treatable Cardiac diseasE (SCIENCE)

AIMS

Ischaemic heart failure (IHF) patients have a poor prognosis even with current guideline-derived therapy. Intramyocardial injections of autologous or allogeneic mesenchymal stromal cells might improve cardiac function leading to better clinical outcome.

METHODS

The SCIENCE (Stem Cell therapy in IschEmic Non-treatable Cardiac diseasE) consortium has initiated a Horizon 2020 funded multicentre phase II study in six European countries. It is a double-blind, placebo-controlled trial testing the safety and efficacy of allogeneic Cardiology Stem Cell Centre Adipose-derived Stromal Cells (CSCC_ASC) from healthy donors or placebo in 138 symptomatic IHF patients. Main inclusion criteria are New York Heart Association class II-III, left ventricular ejection fraction < 45% and N-terminal pro-B-type natriuretic peptide levels > 300 pg/mL. Patients are randomized in a 2:1 pattern to receive intramyocardial injections of either CSCC_ASC or placebo. CSCC_ASC and placebo treatments are prepared centralized at Rigshospitalet in 5 mL vials as an off-the-shelf product. Vials are distributed to all clinical partners and stored in nitrogen vapour tanks ready to be used directly after thawing. A total of 100 × 10⁶ CSCC_ASC or placebo are injected directly into viable myocardium in the infarct border zone using the NOGA XP system (BDS, Cordis, Johnson & Johnson, USA). Primary endpoint is a centralized core-laboratory assessed change in left ventricular end-systolic volume at 6-month follow-up measured by echocardiography. The trial started in January 2017, 58 patients were included and treated until July 2018.

CONCLUSION

The SCIENCE trial will provide clinical data on efficacy and safety of intramyocardial cell therapy of allogeneic adipose-derived stromal cells from healthy donors in patients with IHF.

Laminin as a Potent Substrate for Large-Scale Expansion of Human Induced Pluripotent Stem Cells in a Closed Cell Expansion System

The number of high-quality cells required for engineering an adult human-sized bioartificial organ is greater than one billion. Until the emergence of induced pluripotent stem cells (iPSCs), autologous cell sources of this magnitude and with the required complexity were not available. Growing this number of cells in a traditional 2D cell culture system requires extensive time, resources, and effort and does not always meet clinical requirements. The use of a closed cell culture system is an efficient and clinically applicable method that can be used to expand cells under controlled conditions. We aimed to use the Quantum Cell Expansion System (QES) as an iPSC monolayer-based expansion system. Human iPSCs were expanded (up to 14-fold) using the QES on two different coatings (laminin 521 (LN521) and vitronectin (VN)), and a karyotype analysis was performed. The cells were characterized for spontaneous differentiation and pluripotency by RT-PCR and flow cytometry. Our results demonstrated that the QES provides the necessary environment for exponential iPSC growth, reaching 689.75 × 10⁶ ± 86.88 × 10⁶ in less than 7 days using the LN521 coating with a population doubling level of 3.80 ± 0.19. The same result was not observed when VN was used as a coating. The cells maintained normal karyotype (46-XX), expressed pluripotency markers (OCT4, NANOG, LIN28, SOX2, REX1, DPPA4, NODAL, TDGFb, TERT3, and GDF), and expressed high levels of OCT4, SOX2, NANOG, SSEA4, TRA1-60, and TRA1-81. Spontaneous differentiation into ectoderm (NESTIN, TUBB3, and NEFH), mesoderm (MSX1, BMP4, and T), and endoderm (GATA6, AFP, and SOX17) lineages was detected by RT-PCR with both coating systems. We conclude that the QES maintains the stemness of iPSCs and is a promising platform to provide the number of cells necessary to recellularize small human-sized organ scaffolds for clinical purposes.

Addressing the Manufacturing Challenges of Cell-Based Therapies

Exciting developments in the cell therapy field over the last decades have led to an increasing number of clinical trials and the first cell products receiving marketing authorization. In spite of substantial progress in the field, manufacturing of cell-based therapies presents multiple challenges that need to be addressed in order to assure the development of safe, efficacious, and cost-effective cell therapies.The manufacturing process of cell-based therapies generally requires tissue collection, cell isolation, culture and expansion (upstream processing), cell harvest, separation and purification (downstream processing), and, finally, product formulation and storage. Each one of these stages presents significant challenges that have been the focus of study over the years, leading to innovative and groundbreaking technological advances, as discussed throughout this chapter.Delivery of cell-based therapies relies on defining product targets while controlling process variable impact on cellular features. Moreover, commercial viability is a critical issue that has had damaging consequences for some therapies. Implementation of cost-effectiveness measures facilitates healthy process development, potentially being able to influence end product pricing.Although cell-based therapies represent a new level in bioprocessing complexity in every manufacturing stage, they also show unprecedented levels of therapeutic potential, already radically changing the landscape of medical care.

Tech news: stem cells for modeling and curing disease

Freya Leask explores developments in cell culture and stem cell research that are revolutionizing how diseases are studied and treated.

Evaluation of reagents used to coat the hollow-fiber bioreactor membrane of the Quantum® Cell Expansion System for the culture of human mesenchymal stem cells

The addition of a coating reagent to promote cell adherence is necessary to prepare the membrane surface of the Quantum® Cell Expansion System hollow-fiber bioreactor for the culture of mesenchymal stem cells. In this study, the efficacy of 8 potential coating reagents has been compared in terms of the doubling times of their cell populations, cell morphology, characterization via flow cytometry, and capacity for trilineage differentiation. Human fibronectin (FN), pooled human cryoprecipitate (CPPT), and recombinant human vitronectin (VN) were successful as coating reagents, and each product has advantages in different cell culture contexts. Mesenchymal stem cells harvested from Quantum cultured with each of these 3 compounds as coating reagents all met International Society for Cellular Therapy standards for plastic adherence, surface marker expression, and successful trilineage differentiation. No significant differences were observed among the doubling times from Quantum harvests using FN, CPPT, or VN as coating reagents (P = 0.31). Coating with gelatin, human serum albumin, collagen I, poly‑l‑lysine, and poly‑d‑lysine resulted in significantly lower harvest yield; these agents are not recommended for use as coating reagents in the Quantum system.

GMP Production and Scale-Up of Adherent Neural Stem Cells with a Quantum Cell Expansion System

Cell-based therapies hold great promise for a myriad of clinical applications. However, as these therapies move from phase I to phase II and III trials, there is a need to improve scale-up of adherent cells for the production of larger good manufacturing practice (GMP) cell banks. As we advanced our neural stem cell (NSC)-mediated gene therapy trials for glioma to include dose escalation and multiple treatment cycles, GMP production using cell factories (CellStacks) generated insufficient neural stem cell (NSC) yields. To increase yield, we developed an expansion method using the hollow fiber quantum cell expansion (QCE) system. Seeding of 5.2 × 10⁷ NSCs in a single unit yielded up to 3 × 10⁹ cells within 10 days. These QCE NSCs showed genetic and functional stability equivalent to those expanded by conventional flask-based methods. We then expanded the NSCs in 7 units simultaneously to generate a pooled GMP-grade NSC clinical lot of more than 1.5 × 10¹⁰ cells in only 9 days versus 8 × 10⁹ over 6 weeks in CellStacks. We also adenovirally transduced our NSCs within the QCE. We found the QCE system enabled rapid cell expansion and increased yield while maintaining cell properties and reducing process time, labor, and costs with improved efficiency and reproducibility.

Development of large-scale manufacturing of adipose-derived stromal cells for clinical applications using bioreactors and human platelet lysate

In vitro expanded adipose-derived stromal cells (ASCs) are a useful resource for tissue regeneration. Translation of small-scale autologous cell production into a large-scale, allogeneic production process for clinical applications necessitates well-chosen raw materials and cell culture platform. We compare the use of clinical-grade human platelet lysate (hPL) and fetal bovine serum (FBS) as growth supplements for ASC expansion in the automated, closed hollow fibre quantum cell expansion system (bioreactor). Stromal vascular fractions were isolated from human subcutaneous abdominal fat. In average, 95 × 10⁶ cells were suspended in 10% FBS or 5% hPL medium, and loaded into a bioreactor coated with cryoprecipitate. ASCs (P0) were harvested, and 30 × 10⁶ ASCs were reloaded for continued expansion (P1). Feeding rate and time of harvest was guided by metabolic monitoring. Viability, sterility, purity, differentiation capacity, and genomic stability of ASCs P1 were determined. Cultivation of SVF in hPL medium for in average nine days, yielded 546 × 10⁶ ASCs compared to 111 × 10⁶ ASCs, after 17 days in FBS medium. ASCs P1 yields were in average 605 × 10⁶ ASCs (PD [population doublings]: 4.65) after six days in hPL medium, compared to 119 × 10⁶ ASCs (PD: 2.45) in FBS medium, after 21 days. ASCs fulfilled ISCT criteria and demonstrated genomic stability and sterility. The use of hPL as a growth supplement for ASCs expansion in the quantum cell expansion system provides an efficient expansion process compared to the use of FBS, while maintaining cell quality appropriate for clinical use. The described process is an obvious choice for manufacturing of large-scale allogeneic ASC products.

Mesenchymal Stromal Cells: From Discovery to Manufacturing and Commercialization. Stem Cells Int. 2018;2018:4083921. [PMID: 30057622 PMCID: PMC6051015 DOI: 10.1155/2018/4083921]

Over the last decades, mesenchymal stromal cells (MSC) have been the focus of intense research by academia and industry due to their unique features. MSC can be easily isolated and expanded through in vitro culture by taking full advantage of their self-renewing capacity. In addition, MSC exert immunomodulatory effects and can be differentiated into various lineages, which makes them highly attractive for clinical applications in cell-based therapies. In this review, we attempt to provide a brief historical overview of MSC discovery, characterization, and the first clinical studies conducted. The current MSC manufacturing platforms are reviewed with special attention regarding the use of bioreactors for the production of GMP-compliant clinically relevant cell numbers. The first commercial MSC-based products are also addressed, as well as the remaining challenges to the widespread use of MSC-derived products.

Three-Dimensional Bioreactor Technologies for the Cocultivation of Human Mesenchymal Stem/Stromal Cells and Beta Cells

Diabetes is a prominent health problem caused by the failure of pancreatic beta cells. One therapeutic approach is the transplantation of functional beta cells, but it is difficult to generate sufficient beta cells in vitro and to ensure these cells remain viable at the transplantation site. Beta cells suffer from hypoxia, undergo apoptosis, or are attacked by the host immune system. Human mesenchymal stem/stromal cells (hMSCs) can improve the functionality and survival of beta cells in vivo and in vitro due to direct cell contact or the secretion of trophic factors. Current cocultivation concepts with beta cells are simple and cannot exploit the favorable properties of hMSCs. Beta cells need a three-dimensional (3D) environment to function correctly, and the cocultivation setup is therefore more complex. This review discusses 3D cultivation forms (aggregates, capsules, and carriers) for hMSCs and beta cells and strategies for large-scale cultivation. We have determined process parameters that must be balanced and considered for the cocultivation of hMSCs and beta cells, and we present several bioreactor setups that are suitable for such an innovative cocultivation approach. Bioprocess engineering of the cocultivation processes is necessary to achieve successful beta cell therapy.

Optimizing T Cell Expansion in a Hollow-Fiber Bioreactor

Purpose of Review

Recent developments in regenerative medicine have precipitated the need to expand gene-modified human T cells to numbers that exceed the capacity of well-plate-based, and flask-based processes. This review discusses the changes in process development that are needed to meet the cell expansion requirements by utilizing hollow-fiber bioreactors. Maintenance of cell proliferation over long periods can become limited by unfilled demands for nutrients and oxygen and by the accumulation of waste products in the local environment.

Recent Findings

Perfusion feeding, improved gas exchange, and the efficient removal of lactate can increase the yield of T cells from an average of 10.8E +09 to more than 28E +09 in only 10 days.

Summary

Aggressively feeding cells and actively keeping cells in the bioreactor improves gas exchange and metabolite management over semi-static methods. The ability to remove the environmental constraints that can limit cell expansion by using a two-chamber hollow-fiber bioreactor will be discussed.

Adipose-Derived Stromal Cells for Treatment of Patients with Chronic Ischemic Heart Disease (MyStromalCell Trial): A Randomized Placebo-Controlled Study

We aimed to evaluate the effect of intramyocardial injections of autologous VEGF-A₁₆₅-stimulated adipose-derived stromal cells (ASCs) in patients with refractory angina. MyStromalCell trial is a randomized double-blind placebo-controlled study including sixty patients with CCS/NYHA class II-III, left ventricular ejection fraction > 40%, and at least one significant coronary artery stenosis. Patients were treated with ASC or placebo in a 2 : 1 ratio. ASCs from the abdomen were culture expanded and stimulated with VEGF-A₁₆₅. At 6 months follow-up, bicycle exercise tolerance increased significantly in time duration 22 s (95%CI −164 to 208 s) (P = 0.034), in watt 4 (95%CI −33 to 41, 0.048), and in METs 0.2 (95%CI −1.4 to 1.8) (P = 0.048) in the ASC group while there was a nonsignificant increase in the placebo group in time duration 9 s (95%CI −203 to 221 s) (P = 0.053), in watt 7 (95%CI −40 to 54) (P = 0.41), and in METs 0.1 (95%CI −1.7 to 1.9) (P = 0.757). The difference between the groups was not significant (P = 0.680, P = 0.608, and P = 0.720 for time duration, watt, and METs, resp.). Intramyocardial delivered VEGF-A₁₆₅-stimulated ASC treatment was safe but did not improve exercise capacity compared to placebo. However, exercise capacity increased in the ASC but not in the placebo group. This trial is registered with ClinicalTrials.gov NCT01449032.

Rationale and Design of the First Double-Blind, Placebo-Controlled Trial with Allogeneic Adipose Tissue-Derived Stromal Cell Therapy in Patients with Ischemic Heart Failure: A Phase II Danish Multicentre Study

BACKGROUND

Ischemic heart failure (IHF) has a poor prognosis in spite of optimal therapy. We have established a new allogeneic Cardiology Stem Cell Centre adipose-derived stromal cell (CSCC_ASC) product from healthy donors. It is produced without animal products, in closed bioreactor systems and cryopreserved as an off-the-shelf product ready to use.

STUDY DESIGN

A multicentre, double-blind, placebo-controlled phase II study with direct intramyocardial injections of allogeneic CSCC_ASC in patients with chronic IHF. A total of 81 patients will be randomised at 2 : 1 to CSCC_ASC or placebo. There is no HLA tissue type matching needed between the patients and the donors.

METHODS

The treatment will be delivered by direct injections into the myocardium. The primary endpoint is change in the left ventricle endsystolic volume at 6-month follow-up. Secondary endpoints are safety and changes in left ventricle ejection fraction, myocardial mass, stroke volume, and cardiac output. Other secondary endpoints are change in clinical symptoms, 6-minute walking test, and the quality of life after 6 and 12 months.

CONCLUSION

The aim of the present study is to demonstrate safety and the regenerative efficacy of the allogeneic CSCC_ASC product from healthy donors in a double-blind, placebo-controlled, multicentre study in patients with IHF.

Cryopreserved Off-the-Shelf Allogeneic Adipose-Derived Stromal Cells for Therapy in Patients with Ischemic Heart Disease and Heart Failure-A Safety Study

The present first‐in‐human clinical trial evaluated the safety and feasibility of a newly developed and cryopreserved Cardiology Stem Cell Centre adipose‐derived stromal cell (CSCC_ASC) product from healthy donors for intramyocardial injection in ten patients with ischemic heart disease and ischemic heart failure (IHF). Batches of CSCC_ASC were isolated from three healthy donors by liposuction from abdominal adipose tissue. Adipose mesenchymal stromal cells were culture expanded in bioreactors without the use of animal constituents, cryopreserved, and stored in vials in nitrogen dry‐storage containers until use.

Direct injection of CSCC_ASC into the myocardium did not cause any complications or serious adverse events related to either treatment or cell administration in a 6‐month follow‐up period. Four out of ten heart failure patients developed donor‐specific de novo human leukocyte antigen (HLA) class I antibodies, and two out of ten patients had donor‐specific HLA antibodies already at baseline. There were no clinical symptoms or changes in inflammatory parameters in the follow‐up period that indicated an ongoing immune response. There was a tendency toward improvement in cardiac function after CSCC_ASC treatment at 6‐month follow‐up: left ventricular end systolic volume decreased and left ventricular ejection fraction increased. In addition, exercise capacity increased. These changes were independent of the presence or absence of HLA antibodies.

It is concluded that the newly developed cryopreserved product CSCC_ASC from healthy donors was a safe and feasible treatment. We observed a tendency toward efficacy in patients with IHF. These findings have to be confirmed in larger placebo controlled clinical trials. Stem Cells Translational Medicine2017;6:1963–1971

Influence of patient related factors on number of mesenchymal stromal cells reached after in vitro culture expansion for clinical treatment

BACKGROUND

Number of stromal cells injected in patients with ischaemic heart disease (IHD) may be of importance for the treatment efficacy, which in turn may be influenced by various patient-related factors. In this study, we investigate whether patient-related factors influence the number of autologous stromal cells reached after in vitro culture expansion for clinical therapy.

METHODS

Culture expansion data from 111 patients with IHD treated with autologous stromal cells in three clinical trials were used. We correlated the final cell count after two passages of cultivation with different patient factors.

RESULTS

There was a significant relation between body mass index (BMI) and the number of adipose derived stromal cells (ASCs) reached after culture expansion and for all patients included into the three studies (r = 0.375, p = .019 and r = 0.200, p = .036, respectively). Moreover, there was a significantly higher number of ASCs reached in patients with hypertension compared to those without hypertension and for all patients overall (68.8 ± 39.6 × 10⁶ vs. 39.1 ± 23.6 × 10⁶, p = .020 and 62.0 ± 55.0 × 10⁶ vs. 29.0 ± 19.3 × 10⁶, p < .001, respectively). The same tendency was seen with bone marrow derived mesenchymal stromal cells (MSCs) in patients with hypertension compared to those without hypertension (58.4 ± 61.8 × 10⁶ vs. 22.6 ± 13.3 × 10⁶, p < .001) and in males compared to females (56.4 ± 61.5 × 10⁶ vs. 30.9 ± 27.9 × 10⁶, p = .041). Moreover, a significant negative correlation between left ventricular ejection fraction and number of MSCs was found (r = -0.287, p = .017).

CONCLUSIONS

Patient related factors such as BMI, hypertension and gender may influence the number of MSCs reached after in vitro culture expansion.