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Background: In the last decades the replacement of fetal bovine serum (FBS) with human Platelet Lysate (hPL) for ATMPs expansion has been for a long time investigated to overcome FBS-related issues. Despite several studies confirming hPL safety and efficacy in Mesenchymal Stromal Cell (MSC) expansion, there are still gaps in the knowledge of hPL as a supplement, like the composition and release criteria. As growth factors are released after thrombocytes lysis during hPL production, starting platelet concentration may affect hPL quality. This study aimed to investigate hPL starting platelet concentration effects on bone marrow-derived MSC (BM-MSC) ex-vivo expansion. Methods: MSC were isolated from the bone marrow (BM) of 7 donors and cultured from passage 1 to 5 in 4 different conditions: DMEM 10% FBS and DMEM 5% hPL varying starting platelet concentration. Particularly hPL was produced by in-hospital Transfusion Service, in three different starting platelet concentrations (sPLTC): high (4x109 PLTS/ml), medium (2x109 PLTS/ml) and low (1x109 PLTS/ml). The study focused on the analysis of parameters that are mostly affected by hPL such as cell proliferation, immunophenotype, telomeric length, differentiation and senescence. Results: Evaluation of proliferation indexes (PDT and PD) underlined dose-dependent effects of sPLTC, also confirmed by flow cytometry cell cycle analysis. Immunophenotype seems not to be affected by sPLTC. Differences were instead detected by adhesion molecules markers CD10, CD106, CD166, and CD146 expression, as their expression showed a dose-dependent downregulation, based on the sPLTC. Differentiation potential seems to be unaffected by different sPLTC as all cell batches differentiated into osteoblasts, adipocytes and chondrocytes. On the contrary senescence and relative telomeric length RTL (detected by SA-β-GAL activity and PNA-FITC flow cytometry) are strongly affected by sPLTC, in a dose-dependent manner. Particularly high sPLTC results in cell senescence associated with decreased RTL. Conclusions: our data showed that sPLTC affects some BM MSCs properties, underlying its importance during hPL preparation. According to this study, we suggest a medium sPLTC for hPL preparation, as the best compromise between the increase in proliferation index and effects on senescence.

Background Manufacturing of human Mesenchymal Stromal Cells as advanced therapy medicinal product (ATMP) for clinical use involves an ex vivo expansion, which leads to a risk of contamination by microbiological agents. Even if manufacturing under Good Manufacturing Practice (GMP) license minimizes this risk, contamination of cell cultures by mycoplasmas still represents a widespread problem. Furthermore, the absence of mycoplasma contamination represents one of ATMPs release criteria. Since July 2007, European Pharmacopoeia (EuPh) offers the possibility to replace official mycoplasma detection methods with Nucleic Acid Amplification techniques, after suitable validation. As an Italian authorized Cell Factory, we developed an in-house GMP-compliant validation of real-time PCR method for mycoplasma detection in human Mesenchymal Stromal Cells, according to EuPh sec. 2.6.7 and International Conference on Harmonization Q2. Materials and methods The study was performed in compliance with GMP international requirements with MycoSEQ™ Mycoplasma Detection Assay (Thermofisher) on QuantStudio5 real-Time PCR (Applied Biosystems). Assay validation was developed to evaluate sensitivity, interferences matrix-related, specificity and robustness. Results MycoSEQ™ Mycoplasma Detection Assay has been successfully validated on human Mesenchymal Stromal Cells as results comply with validation protocol acceptance criteria. Conclusions MycoSEQ™ Mycoplasma Detection Assay is a fast, sensitive and specific PCR-based Nucleic Acid Test assay that can be used as an alternative to official mycoplasma test methods for lot release of human Mesenchymal Stromal Cells as advanced therapy medicinal product (ATMP). Moreover, our study underlines the presence of interference on real-time PCR reaction due to matrix composition, pointing out a practical approach for method validation (i.e interference removal).

Background: Hematopoietic progenitor cells (HPCs) cryopreservation have applications, especially in the autologous setting, allowing therapeutic use several years after collection. Cryopreservation...

Background PBSC collection using a blood cell separator in very low weight patients can be frequently complicated by severe adverse effects and technical difficulties. Material and methods From March 2013 to January 2017, 14 PBSC collections were performed in 12 children weighing less than 10 kg, affected by different solid tumours. PBSC collection was performed with a "homemade" aseptically assembled circuit. The circuit is composed by a 150 mL collection bag connected with a 4 stopcock ramp, perfused with ACD. This circuit allows collection of a specific total blood amount from CVC, depending on CD34+ /kg target. Results Mean CD34+ cell performance per collection was 9.3 × 106 /kg. Tolerance to the procedure was very good as none of the patients experienced complications, with the exception of a patient who showed mild cyanosis and pallor after collection. Moreover, no bleeding or thrombotic complications have been observed. To date, 16 PBSC reinfusions have been performed in 7 children with a mean CD34+ cells viability of 98.1% ± 2.7 and mean WBC viability of 57% ± 10. Cell recovery after thawing was 87% ± 10.8. A rapid graft intake for both neutrophils and platelets, between day 7 and 20 after reinfusion was observed. Discussion The procedure of total blood collection without the use of a cell separator is feasible and allows a good PBSC collection without significant side effects in very low-weight children. Moreover, this method could represent a valid and safe alternative to leukapheresis in patients where classic procedure could be difficult to apply.

Background & Aim Background In the last decades the replacement of fetal bovine serum (FBS)with human Platelet Lysate (hPL) for ATMPs clinical expansion has been for a long time investigated to overcome FBS related issues.Despite several studies confirm hPL safety and efficiency in Mesenchymal Stromal Cell(MSC)expansion, there are still some gaps in the knowledge of hPL as cell culture supplement, starting from composition and quality release criteria. Aim of the study As growth factors are released after thrombocytes lysis during hPL production, starting platelet concentration may affect hPL quality.The aim of this study was to investigate hPL starting platelet concentration effects on bone marrow derived MSC(BM-MSC). Methods, Results & Conclusion Material and methods MSC were isolated from the bone marrow of 7 donors and cultured from p1 to p7 in 4 different conditions: DMEM 10% FBS and DMEM 5% hPL varying starting platelet concentration.Particularly hPL was produced according to standardized protocol by in-hospital Transfusion Service, in three different starting platelet concentrations (sPLTC): high sPLTC(4 × 109 PLTS/ml), medium(2 × 109 PLTS/ml) and low(1 × 109 PLTS/ml).The study focused on analysis of parameters that are mostly affected by hPL such as proliferation, immunophenotype, telomeric length, differentiation and cell senescence. Results and Conclusions Evaluation of proliferation indexes(PDT and PD) underlined dose dependent effects of sPLTC (figure 1), also confirmed by flow cytometry cell cycle analysis of BrdU incorporation. Immunophenotype seems not to be affected by sPLTC, as classical MSC markers meet ISCT criteria (table 1). Differences were instead detected by analyzing mean fluorescence intensity (MFI) in a dose dependent manner (figure 2), both for intrinsic and extrinsic parameters. Differentiation potential seems to be unaffected by different sPLTC as all cells batches differentiated into osteoblasts, adipocytes and chondrocytes. On the contrary senescence and relative telomeric length RTL (detected by SA-β-GAL activity and PNA-FITC flow cytometry) are strongly affected by sPLTC, in a dose dependent manner. Particularly high sPLTC results in increased senescent cells associated with decreased RTL (figure 3). In conclusion our data showed that sPLTC affects some BM MSCs properties, underlying its importance during hPL preparation. According to this study we suggest a medium sPLTC for hPL preparation, as best compromise between increase in proliferation index and effects on senescence.

The GvHD is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Extracorporeal photopheresis (ECP) represents an alternative therapeutic strategy to immunosuppressive therapy. Although ECP is used since 1990s, the mechanism of action has not yet been completely clarified. We analyzed cells collected from 20 ECP procedures of 4 patients affected by chronic GvHD and, for comparison, Peripheral Blood Mononuclear Cells (PBMCs) of 10 healthy donors undergoing from same type of photochemiotherapy, evaluating by flow cytometry, the effects before and after photoactivation with 8-MOP. The analysis showed a significant increase in cell death after ECP in particular in CD4 T lymphocytes as described in literature correlated with haematocrit value. Most interesting data emerge from the analysis of cytotoxic activity of NK cells, using flow cytometry analysis of surface expression of CD107a in the presence of target cells (K562). In all analyzed samples it was possible to document a statistically significant reduction of the cytotoxic activity of NK cells after photoactivation. The decrease of the cytotoxic activity was related to hematocrit value of leukoapheresis: in fact, lower HCT values were associated with a more marked reduction of cytotoxic activity. The study confirms literature data about the increase of cellular mortality induce by ECP. Furthermore, for the first time it is demonstrated that the ECP exerts a marked and significant inhibitory effect on the cytotoxic activity of NK cells. Our study suggests that lower values of hematocrit are associated with better treatment outcome.

Background The use of platelet lysate (PL) for the ex-vivo expansion of mesenchymal stromal/stem cells (MSCs) was initially proposed by Doucet et al. in 2005, as an alternative to animal serum. Moreover, regulatory authorities discourage the use of fetal bovine serum (FBS) or other animal derivatives, to avoid risk of zoonoses and xenogeneic immune reactions. Even if many studies investigated PL composition, there still are some open issues related to its use in ex-vivo MSC expansion, especially according to good manufacturing practice (GMP) grade protocols. Methods As an authorized cell factory, we report our experience using standardized PL produced by Azienda Ospedaliero Universitaria Meyer Transfusion Service for MSC expansion according to a GMP grade clinical protocol. As suggested by other authors, we performed an in-vitro test on MSCs versus MSCs cultured with FBS that still represents the best way to test PL batches. We compared 12 MSC batches cultured with DMEM 5% PL with similar batches cultured with DMEM 10% FBS, focusing on the MSC proliferation rate, MSC surface marker expression, MSC immunomodulatory and differentiation potential, and finally MSC relative telomere length. Results Results confirmed the literature data as PL increases cell proliferation without affecting the MSC immunophenotype, immunomodulatory potential, differentiation potential and relative telomere length. Conclusions PL can be considered a safe alternative to FBS for ex-vivo expansion of MSC according to a GMP grade protocol. Our experience confirms the literature data: a large number of MSCs for clinical applications can be obtained by expansion with PL, without affecting the MSC main features. Our experience underlines the benefits of a close collaboration between the PL producers (transfusion service) and the end users (cell factory) in a synergy of skills and experiences that can lead to standardized PL production. Electronic supplementary material The online version of this article (10.1186/s13287-018-0863-8) contains supplementary material, which is available to authorized users.

The aim of this study was to identify empirical relationships among 12 water chemistry parameters, microcystins, and coliform bacteria at four beaches in Lake Winnipeg, Canada. While microcystin fluctuations were not synchronized among the different sites, concentrations were marginally correlated with concurrent nitrate levels at individual sites, but lagged more significantly behind soluble inorganic phosphorus, and inversely behind the nitrate-N/soluble phosphorus ratio (NPR). Microcystins were also inversely correlated with copper, which was used as an algaecide in the lake. Total coliform bacterial counts (TC) were significantly greater at times of increased turbidity, temperature, and higher inorganic phosphate and dissolved organic matter. TC were also inversely correlated with NPR.