Generation of stem cell-based bioartificial anterior cruciate ligament (ACL) grafts for effective ACL rupture repair

AbstractIn the present study, we combined stem cell technology with a non-absorbable biomaterial for the reconstruction of the ruptured ACL. Towards this purpose, multipotential stromal cells derived either from subcutaneous human adipose tissue (hAT-MSCs) or from induced pluripotent stem cells (iPSCs) generated from human foreskin fibroblasts (hiPSC-MSCs) were cultured on the biomaterial for 21days in vitro to generate a 3D bioartifical ACL graft. Stem cell differentiation towards bone and ligament at the ends and central part of the biomaterial was selectively induced using either BMP-2/FGF-2 or TGF-β/FGF-2 combinations, respectively. The bioartificial ACL graft was subsequently implanted in a swine ACL rupture model in place of the surgically removed normal ACL. Four months post-implantation, the tissue engineered ACL graft generated an ACL-like tissue exhibiting morphological and biochemical characteristics resembling those of normal ACL

Sustainable Business Models for Sustainable Concrete – The Triple Layered Proposition

Addressing the growing need for sustainability, novel concrete solutions become increasingly popular for mitigating the negative environmental impacts found in cement production, such as high CO2 emissions output and raw materials overuse, providing conventional concrete products alternatives. The industry is lacking a common analytical framework for business models to clearly define sustainable concrete value streams present across economic, environmental, and social layers. Our research utilises the Triple-Layer Business Model Canvas (TL-BMC) to analyse a piloted sustainable concrete product (CIRCLE), describes its multi-layered value, and effectively provides the common framework for sustainable concrete business model adaptation. We conclude that the Triple-Layered Business Model Canvas (TL-BMC) is the most appropriate framework that enables the identification and establishment of successful business models focused on sustainable concrete

Umbilical cord mesenchymal stem cells for COVID-19 acute respiratory distress syndrome: A double-blind, phase 1/2a, randomized controlled trial

Acute respiratory distress syndrome (ARDS) in COVID-19 is associated with high mortality. Mesenchymal stem cells are known to exert immunomodulatory and anti-inflammatory effects and could yield beneficial effects in COVID-19 ARDS. The objective of this study was to determine safety and explore efficacy of umbilical cord mesenchymal stem cell (UC-MSC) infusions in subjects with COVID-19 ARDS. A double-blind, phase 1/2a, randomized, controlled trial was performed. Randomization and stratification by ARDS severity was used to foster balance among groups. All subjects were analyzed under intention to treat design. Twenty-four subjects were randomized 1:1 to either UC-MSC treatment (n = 12) or the control group (n = 12). Subjects in the UC-MSC treatment group received two intravenous infusions (at day 0 and 3) of 100 ± 20 × 106 UC-MSCs; controls received two infusions of vehicle solution. Both groups received best standard of care. Primary endpoint was safety (adverse events [AEs]) within 6 hours; cardiac arrest or death within 24 hours postinfusion). Secondary endpoints included patient survival at 31 days after the first infusion and time to recovery. No difference was observed between groups in infusion-associated AEs. No serious adverse events (SAEs) were observed related to UC-MSC infusions. UC-MSC infusions in COVID-19 ARDS were found to be safe. Inflammatory cytokines were significantly decreased in UC-MSC-treated subjects at day 6. Treatment was associated with significantly improved patient survival (91% vs 42%, P =.015), SAE-free survival (P =.008), and time to recovery (P =.03). UC-MSC infusions are safe and could be beneficial in treating subjects with COVID-19 ARDS

Umbilical cord mesenchymal stem cells (UC MSCs) as an alternative source to bone marrow (BM) for tissue regeneration applications

Introduction: Human umbilical cord (UC) may be a good source of mesenchymal stem cells (MSCs) for musculoskeletal tissue engineering, however their potential to form bone is incompletely understood. The aim of the present study was to evaluate the growth characteristics, the phenotype and the multipotentiality of UC MSCs in comparison to bone marrow (8M) MSCs, with a particular focus on the molecules involved in bone formation and vascular support. The phenotype of UC endothelial cells (ECs) was additionally investigated in order to isolate uncultured fractions of UC MSCs and ECs, and to compare their telomere status. Methodology: UC fragments were enzymatically digested and UC MSC and EC cultures were grown in specialised media. Quantitative in vitro assays were used to study osteogenic, chondrogenic, adipogenic and vessel formation capacities of UC MSCs in comparison to 8M MSCs. Phenotypic characterisation was performed using multiparameter flow cytometry with MSC-, EC-specific and haematopoietic lineage markers. Immunohistochemistry on UC tissue sections was undertaken to study cell topography and cell sorting was performed to purify putative native UC MSCs from whole UC digests. Relative telomere lengths were measured by qPCR in both cultured and purified UC MSCs. Gene expression was analysed using Taqman low density array for 48 transcripts chosen to reflect MSC osteogenenic, angiogenic and other lineage potentials. Results: Compared to BM MSCs, UC MSCs grew slightly faster and had greater telomere stability. Both BM and UC MSCs had a classic MSC phenotype (CD90•, CD73•, CD105•, CD146•, CD31-, CD34-, CD45-, CD235a'), UC MSCs could generate all three mesenchymal lineages but their differentiation levels were inferior to 8M MSCs. MSCs differentiated towards vasculogenesis on 3-D Matrigel scaffold but they did not differentiate towards mature C031+ ECs. Cells expressing MSC markers C090 and C0146 were mainly located in UC perivascular and Wharton's jelly areas. Putative native UC MSCs were electrostatically cell sorted based on the CD146+, CD45-, CD31' phenotype. Their telomere lengths were compared to electrostatically cell sorted CD146-, CD45-, CD31- cells and ECs (CD45-, CD31•) but contrary to the initial hypothesis, no differences in telomere lengths were found. In agreement with functional osteogenesis assays, UC MSCs expressed considerably lower levels (<5-200 fold) of osteogenesis-related transcripts compared to 8M MSCs. Although they were able to respond to osteogenic v stimulation by up-regulation of many osteogenesis-related molecules (up to 100- fold), the transcript expression levels of differentiated 8M MSCs were commonly not achieved. Conclusions: UC MSCs direct differentiation in standard osteogenic assays appeared inferior to BM MSCs, most likely due to their more immature status. However, UC digests could represent a potential source of regenerative cens (MSCs and ECs) for complex tissue engineering where functional and long-lasting vasculature is required. It is possible that bone-forming capacity of UC MSCs can be improved by the development of optimised expansion protocols andlor the use of purified uncultured MSCs.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Increased Mesenchymal Stem Cell Functionalization in Three-Dimensional Manufacturing Settings for Enhanced Therapeutic Applications

Mesenchymal stem/stromal cell (MSC) exist within their in vivo niches as part of heterogeneous cell populations, exhibiting variable stemness potential and supportive functionalities. Conventional extensive 2D in vitro MSC expansion, aimed at obtaining clinically relevant therapeutic cell numbers, results in detrimental effects on both cellular characteristics (e.g., phenotypic changes and senescence) and functions (e.g., differentiation capacity and immunomodulatory effects). These deleterious effects, added to the inherent inter-donor variability, negatively affect the standardization and reproducibility of MSC therapeutic potential. The resulting manufacturing challenges that drive the qualitative variability of MSC-based products is evident in various clinical trials where MSC therapeutic efficacy is moderate or, in some cases, totally insufficient. To circumvent these limitations, various in vitro/ex vivo techniques have been applied to manufacturing protocols to induce specific features, attributes, and functions in expanding cells. Exposure to inflammatory cues (cell priming) is one of them, however, with untoward effects such as transient expression of HLA-DR preventing allogeneic therapeutic schemes. MSC functionalization can be also achieved by in vitro 3D culturing techniques, in an effort to more closely recapitulate the in vivo MSC niche. The resulting spheroid structures provide spatial cell organization with increased cell–cell interactions, stable, or even enhanced phenotypic profiles, and increased trophic and immunomodulatory functionalities. In that context, MSC 3D spheroids have shown enhanced “medicinal signaling” activities and increased homing and survival capacities upon transplantation in vivo . Importantly, MSC spheroids have been applied in various preclinical animal models including wound healing, bone and osteochondral defects, and cardiovascular diseases showing safety and efficacy in vivo . Therefore, the incorporation of 3D MSC culturing approach into cell-based therapy would significantly impact the field, as more reproducible clinical outcomes may be achieved without requiring ex vivo stimulatory regimes. In the present review, we discuss the MSC functionalization in 3D settings and how this strategy can contribute to an improved MSC-based product for safer and more effective therapeutic applications

The Ongoing Epidemic of West Nile Virus in Greece: The Contribution of Biological Vectors and Reservoirs and the Importance of Climate and Socioeconomic Factors Revisited

Emerging infectious diseases have inflicted a significant health and socioeconomic burden upon the global population and governments worldwide. West Nile virus, a zoonotic, mosquito-borne flavivirus, was originally isolated in 1937 from a febrile patient in the West Nile Province of Uganda. It remained confined mainly to Africa, the Middle East, and parts of Europe and Australia until 1999, circulating in an enzootic mosquito-bird transmission cycle. Since the beginning of the 21st century, a new, neurotropic, more virulent strain was isolated from human outbreaks initially occurring in North America and later expanding to South and South-eastern Europe. Since 2010, when the first epidemic was recorded in Greece, annual incidence has fluctuated significantly. A variety of environmental, biological and socioeconomic factors have been globally addressed as potential regulators of the anticipated intensity of the annual incidence rate; circulation within the zoonotic reservoirs, recruitment and adaptation of new potent arthropod vectors, average winter and summer temperatures, precipitation during the early summer months, and socioeconomic factors, such as the emergence and progression of urbanization and the development of densely populated areas in association with insufficient health policy measures. This paper presents a review of the biological and socioenvironmental factors influencing the dynamics of the epidemics of West Nile virus (WNV) cases in Greece, one of the highest-ranked European countries in terms of annual incidence. To date, WNV remains an unpredictable opponent as is also the case with other emerging infectious diseases, forcing the National Health systems to develop response strategies, control the number of infections, and shorten the duration of the epidemics, thus minimizing the impact on human and material resources

Human infrapatellar fat pad mesenchymal stem cells show immunomodulatory exosomal signatures

Within the human knee infrapatellar fat pad (IFP) and synovium, resident synoviocytes and macrophages contribute to the onset and progression of inflammatory joint diseases. Our hypothesis is that IFP-derived mesenchymal stem cells (IFP-MSC) robust immunomodulatory therapeutic effects are largely exerted via their exosomal (IFP-MSC EXOs) secretome by attenuating synoviocytes and macrophages pro-inflammatory activation. IFP-MSC EXOs showed distinct miRNA and protein immunomodulatory profiles. Reactome analysis of 24 miRNAs highly present in exosomes showed their involvement in the regulation of six gene groups, including immune system. Exosomes were enriched for immunomodulatory and reparative proteins that are involved in positive regulation of cell proliferation, response to stimulus, signal transduction, signal receptor activity, and protein phosphorylation. Stimulated synoviocytes or macrophages exposed to IFP-MSC EXOs demonstrated significantly reduced proliferation, altered inflammation-related molecular profiles, and reduced secretion of pro-inflammatory molecules compared to stimulated alone. In an acute synovial/IFP inflammation rat model, IFP-MSC EXOs therapeutic treatment resulted in robust macrophage polarization towards an anti-inflammatory therapeutic M2 phenotype within the synovium/IFP tissues. Based on these findings, we propose a viable cell-free alternative to MSC-based therapeutics as an alternative approach to treating synovitis and IFP fibrosis

Characterization and response to inflammatory stimulation of human endometrial-derived mesenchymal stem/stromal cells

The human endometrium has emerged as an attractive source of endometrial-derived mesenchymal stem/stromal cells (eMSCs) that can be easily isolated by non-invasive procedures. The prominent capacity of the endometrium for efficient and scarless regeneration each menstrual cycle indicates the increased eMSC immunomodulatory and pro-angiogenic properties. Herein the authors investigated the molecular responses of eMSCs to an inflammatory environment and whether those intrinsic responses affected their functional attributes. Human eMSCs immunophenotypic, transcriptional and secretory profiles were evaluated at passage three (P3) and passage eight (P8) to determine culture effects. Functionally, P3 and P8 non-induced and TNF-α/IFN-γ-induced eMSCs were interrogated for their capacity to suppress stimulated peripheral blood mononuclear cell (PBMC) proliferation, whereas non-induced eMSCs were assessed for their support to vascular network formation in co-cultures with human umbilical vein endothelial cells in vitro. Non-induced P3 and P8 eMSCs exhibited similar spindle-shaped morphology and clonogenic capacity. Nevertheless, P8 eMSCs showed reduced growth rate capacity and telomere length. The eMSCs displayed the typical MSC-related immunophenotypic profile, with P3 and P8 eMSCs expressing high levels (>98%) of CD140β, intermediate levels (35–60%) of CD146 and SUSD2 and low levels (∼8%) of NG2 pericytic markers. Non-induced P3 and P8 showed similar transcriptional and secretory profiles, though the expression of immunomodulatory HLA-G and IL-8 genes was significantly downregulated in P8 compared with P3 eMSCs. Upon TNF-α/IFN-γ induction, eMSCs showed an immunophenotypic profile similar to that of non-induced eMSCs, except for significant upregulation of HLA-DR protein expression in both induced P3 and P8 eMSCs. However, induced P3 and P8 eMSCs showed significant upregulation of CD10, HLA-G, IDO, IL-6, IL-8, LIF and TSG gene expression compared with non-induced cultures. TNF-α/IFN-γ induction strongly increased the secretion of inflammatory-/angiogenesis-related molecules, whereas growth factor secretion was similar to the non-induced eMSCs. Functionally, P3 and P8 eMSCs showed a strong inhibitory effect on stimulated PBMC proliferation and the capacity to support neovascularization in vitro. The authors’ study suggests that serial expansion does not affect eMSC immunophenotypic, transcriptional and secretory profiles. This is directly reflected by the functional immunomodulatory and pro-angiogenic properties of eMSCs, which remain unaltered until P8 in vitro. However, exposure of eMSCs to inflammatory environments enhances their immunomodulatory transcriptional and inflammatory-/angiogenesis-related secretory profiles. Therefore, the resulting evidence of eMSCs serial expansion and exposure to inflammation could serve as a foundation for improved eMSCs manufacturing and potential clinical translation efforts. Experimental design illustrating endometrial tissue obtained from the second day of menstrual cycle, endometrial-derived mesenchymal stem/stromal cell (eMSC) isolation and expansion, eMSC inflammatory stimulation and eMSC profiling and functionality assessments in vitro. [Display omitted