Label-free toxicology screening of primary human mesenchymal cells and iPS-derived neurons

The high-throughput, label-free Corning Epic assay has applications in drug discovery, pharmacogenomics, cell receptor signaling, cell migration, and viral titration. The utility of Epic technology for biocompatibility testing has not been well established. In manufacturing of medical devices, in vitro and in vivo biocompatibility assessments are mandatory, according to ISO 10993. The new medical device regulation MDR 745/2017 specifies that ex vivo assays that can closely recapitulate in vivo scenarios are needed to better evaluate biomedical devices. We propose herein that Epic technology\u2014which enables detection of variations in cell mass distribution\u2014is suitable for biocompatibility screening of compounds. In this study, we challenged primary human osteoblasts, endothelial cells, and neurons derived from induced pluripotent stem cells with specific concentrations of methyl methacrylate (MMA). Polymeric MMA has long been applied in cranioplasty, where it makes contact with multiple cell types. Application of Epic technology yielded real-time cytotoxicity profiles for all considered cell types. The results were compared with those from microscopic observation of the same culture plate used in the Epic analyses. The Epic assay should be further examined for its utility for cell biology, genomics, and proteomics companion assays. Our results suggest that Epic technology can be applied to biocompatibility evaluation of human cells in medical device development

Adipose stromal/stem cells assist fat transplantation reducing necrosis and increasing graft performance.

Autologous fat transfer (AFT) is a procedure for adipose tissue (AT) repair after trauma, burns, post-tumor resections and lipodystrophies still negatively impacted by the lack of graft persistence. The reasons behind this poor outcome are unclear and seem to involve damages in either harvested/transplanted mature adipocytes or on their mesenchymal progenitors, namely adipose stromal/stem cells (ASC), and due to post-transplant AT apoptosis and involution. A rabbit subcutaneous AT regeneration model was here developed to first evaluate graft quality at different times after implant focusing on related parameters, such as necrosis and vasculogenesis. Standard AFT was compared with a strategy where purified autologous ASC, combined with hyaluronic acid (HA), assisted AFT. Five million of autologous ex vivo isolated CD29+, CD90+, CD49e+ ASC, loaded into HA, enriched 1 ml of AT generating an early significant protective effect in reducing AFT necrosis and increasing vasculogenesis with a preservation of transplanted AT architecture. This beneficial impact of ASC assisted AFT was then confirmed at three months with a robust lipopreservation and no signs of cellular transformation. By a novel ASC assisted AFT approach we ensure a reduction in early cell death favoring an enduring graft performance possibly for a more stable benefit in patients

Understanding Tumor-Stroma Interplays for Targeted Therapies by Armed Mesenchymal Stromal Progenitors: The Mesenkillers.

Tumor represents a complex structure containing malignant cells strictly coupled with a large variety of surroundingcells constituting the tumor stroma (TS). In recent years, the importance of TS for cancer initiation, development,local invasion and metastases became increasingly clear allowing the identification of TS as one of the possibleways to indirectly target tumors. Inside the heterogeneous stromal cell population, tumor associated fibroblasts(TAF) play a crucial role providing both functional and supportive environments. During both tumor and stroma development,several findings suggest that TAF could be recruited from different sources such as locally derived host fibroblasts,via epithelial/endothelial mesenchymal transitions or from circulating pools of fibroblasts deriving form mesenchymalprogenitors, namely mesenchymal stem/stromal cells (MSC). These insights prompted scientists to identifymultimodal approaches to target TS by biomolecules, monoclonal antibodies and, more recently, via cell basedstrategies. These latter appear extremely promising, although associated with still debated and unclear findings. Thisreview discusses on crosstalk between cancers and their stroma, dissecting specific tumor types, such as sarcoma,pancreatic and breast carcinoma where stroma plays distinct paradigmatic roles. The recognition of these distinctstromal functions may help in planning effective and safer approaches aimed either to eradicate or to substitute TSby novel compounds and/or MSC having specific killing activitie

Human Adipose Mesenchymal Stromal/Stem Cells Improve Fat Transplantation Performance

The resorption rate of autologous fat transfer (AFT) is 40-60% of the implanted tissue, requiring new surgical strategies for tissue reconstruction. We previously demonstrated in a rabbit model that AFT may be empowered by adipose-derived mesenchymal stromal/stem cells (AD-MSCs), which improve graft persistence by exerting proangiogenic/anti-inflammatory effects. However, their fate after implantation requires more investigation. We report a xenograft model of adipose tissue engineering in which NOD/SCID mice underwent AFT with/without human autologous AD-MSCs and were monitored for 180 days (d). The effect of AD-MSCs on AFT grafting was also monitored by evaluating the expression of CD31 and F4/80 markers. Green fluorescent protein-positive AD-MSCs (AD-MSC-GFP) were detected in fibroblastoid cells 7 days after transplantation and in mature adipocytes at 60 days, indicating both persistence and differentiation of the implanted cells. This evidence also correlated with the persistence of a higher graft weight in AFT-AD-MSC compared to AFT alone treated mice. An observation up to 180 d revealed a lower resorption rate and reduced lipidic cyst formation in the AFT-AD-MSC group, suggesting a long-term action of AD-MSCs in support of AFT performance and an anti-inflammatory/proangiogenic activity. Together, these data indicate the protective role of adipose progenitors in autologous AFT tissue resorption

Characteristics and Potentiality of Human Adipose-Derived Stem Cells (hASCs) Obtained from Enzymatic Digestion of Fat Graft

Human adipose-derived stem cells localize in the stromal-vascular portion, and can be ex vivo isolated using a combination of washing steps and enzymatic digestion. For this study, we undertook a histological evaluation of traditional fat graft compared with fat graft enriched with stromal vascular fraction cells isolated by the Celution™ system to assess the interactions between cells and adipose tissue before the breast injection. In addition, we reported on histological analyses of biopsies derived from fat grafted (traditional or enriched with SVFs) in the breast in order to assess the quality of the adipose tissue, fibrosis and vessels. The hASCs derived from enzymatic digestion were systematically characterized for growth features, phenotype and multi-potent differentiation potential. They fulfill the definition of mesenchymal stem cells, albeit with a higher neural phenotype profile. These cells also express genes that constitute the core circuitry of self-renewal such as OCT4, SOX2, NANOG and neurogenic lineage genes such as NEUROD1, PAX6 and SOX3. Such findings support the hypothesis that hASCs may have a potential usefulness in neurodegenerative conditions. These data can be helpful for the development of new therapeutic approaches in personalized medicine to assess safety and efficacy of the breast reconstruction

An Alternative Approach to Investigate Biofilm in Medical Devices: A Feasibility Study

Biofilms are assemblages of bacterial cells irreversibly associated with a surface where moisture is present. In particular, they retain a relevant impact on public health since through biofilms bacteria are able to survive and populate biomedical devices causing severe nosocomial infections that are generally resistant to antimicrobial agents. Therefore, controlling biofilm formation is a mandatory feature during medical device manufacturing and during their use. In this study, combining a crystal violet staining together with advanced stereomicroscopy, we report an alternative rapid protocol for both qualitative and semi-quantitative biofilm determination having high specificity, high repeatability, and low variability. The suggested approach represents a reliable and versatile method to detect, monitor, and measure biofilm colonization by an easy, more affordable, and reproducible method

Method For Obtaining A Population Of Stromal Progenitor Cells

E' STATO ELABORATO UN NUOVO E ORIGINALE SISTEMA DI ISOLAMENTO DI POPOLAZIONI CELLULARI

MSC and Tumors: Homing, Differentiation and Secretion Influence The Therapeutic Potentials

Mesenchymal stromal/stem cells (MSC) are adult multipotent progenitors with fibroblast-like morphology able to differentiate into adipocytic, osteogenic, chondrogenic, and myogenic lineages. Due to these properties, MSC have been studied and introduced as therapeutics in regenerative medicine. Preliminary studies have also shown a possible involvement of MSC as precursors of cellular elements within tumor microenvironments, in particular tumor-associated fibroblasts (TAF). Among a number of different possible origins, TAF may originate from a pool of circulating progenitors from bone marrow or adipose tissue-derived MSC. There is growing evidence to corroborate that cells immunophenotypically defined as MSC are able to reside as TAF influencing the tumor microenvironment in a potentially bi-phasic and obscure manner: either promoting or inhibiting growth depending on tumor context and MSC sources. Here we focus on relationships between the tumor microenvironment, cancer cells, and MSC, analyzing their diverse ability to influence neoplastic development. Associated activities include MSC homing driven by the secretion of various mediators, differentiation towards TAF phenotypes, and reciprocal interactions with the tumor cells. These are reviewed here with the aim of understanding the biological functions of MSC that can be exploited for innovative cancer therapy

Mesenchymal progenitors aging highlights a mir-196 switch targeting HOXB7 as master regulator of proliferation and osteogenesis

Human aging is associated with a decrease in tissue functions combined with a decline in stem cells frequency and activity followed by a loss of regenerative capacity. The molecular mechanisms behind this senescence remain largely obscure, precluding targeted approaches to counteract aging. Focusing on mesenchymal stromal/stem cells (MSC) as known adult progenitors, we identified a specific switch in miRNA expression during aging, revealing a miR-196a upregulation which was inversely correlated with MSC proliferation through HOXB7 targeting. A forced HOXB7 expression was associated with an improved cell growth, a reduction of senescence, and an improved osteogenesis linked to a dramatic increase of autocrine basic fibroblast growth factor secretion. These findings, along with the progressive decrease of HOXB7 levels observed during skeletal aging in mice, indicate HOXB7 as a master factor driving progenitors behavior lifetime, providing a better understanding of bone senescence and leading to an optimization of MSC performance

Mesenchymal stromal cells for cutaneous wound healing in a rabbit model: Pre-clinical study applicable in the pediatric surgical setting

Objective: Mesenchymal stromal cells (MSCs) expanded in vitro have been proposed as a potential therapy for congenital or acquired skin defects in pediatrics. The aim of this pre-clinical study was to investigate the effects of intradermal injections of MSC in experimental cutaneous wound repair comparing allogeneic and autologous adipose stem cells (ASCs) and autologous bone marrow-mesenchymal stromal cells (BM-MSCs). Methods: Mesenchymal stromal cells were in vitro expanded from adipose and BM tissues of young female New Zealand rabbits. MSCs were characterized for plastic adhesion, surface markers, proliferation and differentiation capacity. When an adequate number of cells (ASCs 10 7 106 and BM-MSCs 3 7 106, because of their low rate of proliferation) was reached, two skin wounds were surgically induced in each animal. The first was topically treated with cell infusions, the second was used as a control. The intradermal inoculation included autologous or allogeneic ASCs or autologous BM-MSCs. For histological examination, animals were sacrificed and wounds were harvested after 11 and 21 days of treatment. Results: Rabbit ASCs were isolated and expanded in vitro with relative abundance, cells expressed typical surface markers (CD49e, CD90 and CD29). Topically, ASC inoculation provided more rapid wound healing than BM-MSCs and controls. Improved re-epithelization, reduced inflammatory infiltration and increased collagen deposition were observed in biopsies from wounds treated with ASCs, with the best result in the autologous setting. ASCs also improved restoration of skin architecture during wound healing. Conclusion: The use of ASCs may offer a promising solution to treat extended wounds. Pre-clinical studies are however necessary to validate the best skin regeneration technique, which could be used in pediatric surgical translational research