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1.
Small ; 20(23): e2305958, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38169107

RESUMO

Simultaneous electroreduction of CO2 and H2O to syngas can provide a sustainable feed for established processes used to synthesize carbon-based chemicals. The synthesis of MOx/M-N-Cs (M = Ni, Fe) electrocatalysts reported via one-step pyrolysis that shows increased performance during syngas electrosynthesis at high current densities with adaptable H2/CO ratios, e.g., for the Fischer-Tropsch process. When embedded in gas diffusion electrodes (GDEs) with optimized hydrophobicity, the NiOx/Ni-N-C catalyst produces syngas (H2/CO = 0.67) at -200 mA cm-2 while for the FeOx/Fe-N-C syngas production occurs at ≈-150 mA cm-2. By tuning the electrocatalyst's microenvironment, stable operation for >3 h at -200 mA cm-2 is achieved with the NiOx/Ni-N-C GDE. Post-electrolysis characterization revealed that the restructuring of the catalyst via reduction of NiOx to metallic Ni NPs still enables stable operation of the electrode at -200 mA cm-2, when embedded in an optimized microenvironment. The ionomer and additives used in the catalyst layer are important for the observed stable operation. Operando Raman measurements confirm the presence of NiOx during CO formation and indicate weak adsorption of CO on the catalyst surface.

2.
Cytotherapy ; 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38703156

RESUMO

BACKGROUND: With the success of chimeric antigen receptor T-cell (CAR-T) and similar cellular-based therapies, the demand for collection of autologous mononuclear cells by apheresis (MNC(A)) from blood by apheresis has increased. From an apheresis technical standpoint, the collection of MNC(A) is relatively straightforward, especially when compared with collection of hematopoietic progenitor cells (HPC(A)). Most of the collection for MNC(A) are performed for the commercial entities, who use the product for manufacturing cellular therapeutics. We have noticed discrepancies in the handling and apheresis processes required by different companies in obtaining essentially the same product (all companies in the study manufacture CAR-T-based products). We have analyzed the MNC collection requirements from all FDA-approved CAR-T cellular products and some investigational products collected at University of Nebraska Medical Center. We identified discrepancies in the process and suggested mitigation strategies. METHODS: Step-by-step analysis of the collection requirements. Review of the current guidelines and recommendations on this issue. RESULTS: Multiple discrepancies in the collection process have been identified, even in the products collected for the same company. Practical approach of satisfying all the requirements based on University of Nebraska Medical Center experience has been suggested. CONCLUSION: The current recommendations from multiple sources were reviewed in discussion.

3.
Small ; 19(44): e2301327, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37415572

RESUMO

The systematical understanding of metal-dependent activity in electrocatalyzing oxygen reduction reaction (ORR), a vital reaction with sluggish kinetics for zinc-air batteries, remains quite unclear. An atomic and spatial engineering modulating ORR activity over hollow carbon quasi-sphere (HCS) confined in a series of single M-N (M = Cu, Mn, Ni) sites is reported here. Based on the theoretical prediction and experimental validation, Cu-N4 site with the lowest overpotential shows a better ORR kinetics than Mn-N4 and Ni-N4 . The ORR activity of single-atom Cu center can be further improved by decreasing the coordination number of N to two, namely Cu-N2 , due to the enhancement of electrons with lower coordination structure. Benefitting from the unique spatial confinement effect of the HCS structure in modulating electronic feature of active sites, the Cu-N2 site confined in HCS also delivers highly improved ORR kinetics and activity relative to that on planner graphene. Additionally, the best catalyst holds excellent promise in the application of zinc-air batteries. The findings will pave a new way to atomically and electronically tune active sites with high efficiency for other single-atom catalysts.

4.
Small ; 19(12): e2205283, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36581564

RESUMO

Single-atom catalysts based on metal-N4 moieties and embedded in a graphite matrix (defined as MNC) are promising for oxygen reduction reaction (ORR). However, the performance of MNC catalysts is still far from satisfactory due to their imperfect adsorption energy to oxygen species. Herein, single-atom FeNC is leveraged as a model system and report an adjacent Ru-N4 moiety modulation effect to optimize the catalyst's electronic configuration and ORR performance. Theoretical simulations and physical characterizations reveal that the incorporation of Ru-N4 sites as the modulator can alter the d-band electronic energy of Fe center to weaken the FeO binding affinity, thus resulting in the lower adsorption energy of ORR intermediates at Fe sites. Thanks to the synergetic effects of neighboring Fe and Ru single-atom pairs, the FeN4 /RuN4 catalyst exhibits a half-wave potential of 0.958 V and negligible activity degradation after 10 000 cycles in 0.1 m KOH. Metal-air batteries using this catalyst in the cathode side exhibit a high power density of 219.5 mW cm-2 and excellent cycling stability for over 2370 h, outperforming the state-of-the-art catalysts.

5.
Transfusion ; 63(8): 1546-1553, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37422880

RESUMO

BACKGROUND: Extracorporeal photopheresis (ECP) treatment, mostly based on apheresis technology, is used for immunomodulation in various diseases such as cutaneous T-cell lymphoma, graft versus host disease and other (auto)immune disorders. The aim of this study was to collect high cell counts and purity in shorter procedure times using an ECP off-line system with an increased collection flow rate of 2 mL/min to a target volume of 200 mL buffy coat. STUDY DESIGN AND METHODS: In this prospective study, data of routinely performed off-line photopheresis treatments were collected and analyzed at the Central Institute for Blood Transfusion & Department of Immunology (ZIB) of the Tirol Kliniken, to assess absolute cell counts and procedure times and to calculate collection efficiencies (CE2). RESULTS: A total of 22 patients participated in this study. The processed blood volume was 4312 mL, the collection time 120 min, overall procedure time 157 min and the absolute cell counts of treated white blood cells (WBC) and mononuclear cells (MNC) were 5.0 and 4.3 × 109 respectively (median values). The calculated CE2 for WBC and MNC was 21.1% and 58.5%, the proportion of treated MNCs of the total number of MNCs present was 55.0%. CONCLUSION: The data presented in this study show high therapeutically effective cell counts collected with a high MNC purity within a shorter overall collection/procedure time due to an increased collection flow rate.


Assuntos
Remoção de Componentes Sanguíneos , Doença Enxerto-Hospedeiro , Fotoferese , Neoplasias Cutâneas , Humanos , Fotoferese/métodos , Estudos Prospectivos , Leucócitos , Doença Enxerto-Hospedeiro/terapia
6.
Transfus Apher Sci ; 62(1): 103517, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35963811

RESUMO

INTRODUCTION: Sufficient stem cell collection is mandatory for Autologous stem cell transplantation (ASCT). Peripheral CD34+ stem CD34 + stem cell counting by flow cytometry is the gold standard method in both the predicting and timing of successful stem cell collection. Large unstained cells (LUC) are large peroxidase-negative cells that are displayed on certain automatic cell counters and present large lymphocytes, virocytes, blasts, abnormal cells and hematopoietic stem cells. In this study, we evaluated the role of LUC parameters in the timing and prediction of successful stem cell collection. METHODS: Patients with a diagnosis of multiple myeloma, lymphoma and testis tumor who proceed to ASCT were included in this study. Preapheresis LUC parameters were analyzed with Siemens ADVIA® 2120i system., Kruskal Wallis, Mann-Whitney U, Spearman Rho and receiver-operator curve (ROC) tests were used for analyses. RESULTS: Ninety patients were evaluated. Peripheral CD34 + cell count was positively correlated with both LUC count (p = 0014) and LUC percentage (p = 0,01). LUC percentage in peripheral blood was positively correlated with mobilized stem cell count in the yield (p = 0.003). We found a LUC count of > 0.485 × 109/L as a cut-off value for detecting > 20 × 106/L CD34 +cells in the peripheral blood with a sensitivity of 64.6% and specificity of 75%. We defined > 2.15% as a cut-off value for LUC percentage to collect > 5 × 106/kg of stem cells with a sensitivity of 64% and specificity of 63%. Additionally, total nucleated cell (TNC) count was negatively correlated with LUC percentage (p = 0.014) and positively correlated with LUC count (p = 0.001). CONCLUSION: LUC parameters are readily available, simple and cheap tools that can be useful in both timing of CD34 count by flow cytometry in peripheral blood and in the prediction of successful mobilization. LUCs can also be an indicator of graft composition.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Masculino , Humanos , Mobilização de Células-Tronco Hematopoéticas/métodos , Transplante Autólogo , Células-Tronco Hematopoéticas/metabolismo , Antígenos CD34/metabolismo
7.
J Clin Apher ; 38(6): 685-693, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37503703

RESUMO

BACKGROUND: Adequate stem cell collection is essential for successful stem cell transplantation. Heparin enhances stem cell mobilization by competing with heparin sulfate proteoglycans. Heparin is also used as an anticoagulant before leukapheresis. Here, we evaluated the effects of heparin on stem cell mobilization in patients who underwent autologous stem cell transplantation (ASCT). METHODS: We evaluated patients who underwent ASCT. Patients were divided into two groups: those who received heparin plus citrate (heparinized patients) and those who received citrate only (nonheparinized patients) for anticoagulation. Univariate and multivariate analyses were also performed. The collection efficiency 2 (CE2) for CD34+ cells was calculated and compared between heparinized and nonheparinized patients. RESULTS: This study included 1017 patients. There were 478 (47%) heparinized and 539 (53%) nonheparinized patients. The number of collected CD34+ cells was significantly higher in heparinized patients (P < .00001). The multivariate analyses showed that using heparin was an independent positive factor for collected CD34+ cells (adj-R2 = 0.744; F = 369.331, P < .00001). CE2 was significantly higher in heparinized patients than in nonheparinized patients (66.8% vs 52.1%; P < .00001). The rate of collecting at least 2 × 106 /kg CD34+ cells was 3.3 times higher for heparinized patients in poor mobilizers (P < .00001). Heparinized patients had significantly higher total nucleated and mononuclear cell counts (P < .00001 and <.00001, respectively). CONCLUSION: Heparin enhances stem cell collection and increases CE2. The use of heparin may reduce the need for other strategies to increase stem cell mobilization.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Humanos , Transplante Autólogo , Mobilização de Células-Tronco Hematopoéticas , Heparina/farmacologia , Heparina/uso terapêutico , Leucaférese , Citratos , Transplante de Células-Tronco , Antígenos CD34/análise , Fator Estimulador de Colônias de Granulócitos/farmacologia , Fator Estimulador de Colônias de Granulócitos/uso terapêutico
8.
Cell Tissue Bank ; 24(4): 685-691, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36735100

RESUMO

The purpose of this study was to explore methods of selectively enriching CD34 + haematopoietic progenitor cells (HPC) in mononuclear cell (MNC) preparations, and to outline a procedure for cryopreservation and thawing of manufactured material. Density gradient centrifugation of umbilical cord blood was achieved using Ficoll-Paque™ media at 1.077 g/mL and 1.065 g/mL densities and Leucosep preparation tubes. Post-process samples were analysed for CD34 + and MNC content. Finally, MNCs were frozen down at a concentration of 8.5 × 106 cells/mL in CryoStor CS10 using an Asymptote VIAFreeze controlled rate freezer at a rate of - 2 °C per minute, then thawed and analysed for viability and recovery. Processing with 1.065 g/mL media selectively depleted non-HPC cell types, producing an approximately fourfold increase in CD34 + frequency (M ± 1SD = 1.4 ± 1.3%, P < 0.01) relative to the pre-process sample (M ± 1SD = 0.4 ± 0.3%), whereas 1.077 g/mL media produced only a twofold enrichment (0.7 ± 0.6, P < 0.01). This was not accompanied by any significant forfeit of CD34 + recovery (79 ± 32% vs. 78 ± 32% respectively; P = 0.87). The MNCs generated by the 1.065 g/mL procedure were of greater purity (96 ± 2%) than in the 1.077 g/mL procedure (80 ± 7%, P < 0.01). Post-thaw, MNC viability was 95 ± 1% and CD34 + viability was 98 ± 1%. Ultra-pure MNCs rich in CD34 + HPCs can be generated with a simple, inexpensive modification to Ficoll-Paque™ media. These products can be easily cryopreserved using a simple controlled rate freezing procedure.


Assuntos
Sangue Fetal , Células-Tronco Hematopoéticas , Ficoll , Antígenos CD34/análise , Criopreservação/métodos , Sobrevivência Celular
9.
Small ; 18(18): e2200395, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35384295

RESUMO

Carbon-based single metal atom catalysts (SACs) are being extensively investigated to improve the kinetics of the Li-S redox reaction, which is greatly important for batteries with cell-level energy densities >500 W h kg-1 . However, there are contradictory reports regarding the electrocatalytic activities of the different metal atoms and the role of the metal atom in LiS chemistry still remains unclear. This is due to the complex relationship between the catalytic behavior and the structure of carbon-based SACs. Here, the catalytic behavior and active-site geometry, oxidation state, and the electronic structure of different metal centers (Fe/Co/Ni) embedded in nitrogen-doped graphene, and having similar physicochemical characteristics, are studied. Combining X-ray absorption spectroscopy, density functional theory calculations, and electrochemical analysis, it is revealed that the coordination-geometry and oxidation state of the metal atoms are modified when interacting with sulfur species. This interaction is strongly dependent on the hybridization of metal 3d and S p-orbitals. A moderate hybridization with the Fermi level crossing the metal 3d band is more favorable for LiS redox reactions. This study thus provides a fundamental understanding of how metal atoms in SACs impact LiS redox behavior and offers new guidelines to develop highly active catalytic materials for high-performance LiS batteries.


Assuntos
Carbono , Metais , Carbono/química , Catálise , Metais/química , Nitrogênio/química , Oxirredução
10.
Angew Chem Int Ed Engl ; 60(23): 12759-12764, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33646597

RESUMO

Nitrogen-doped graphene could catalyze the electrochemical reduction and evolution of oxygen, but unfortunately suffers from sluggish catalytic kinetics. Herein, for the first time, we report an onion-like carbon coated Co, N-doped carbon (OLC/Co-N-C) material, which possesses multilayers of highly curved nanostructures that form mesoporous architectures. These unique nanospheres are produced when surfactant micelles are introduced to synthesis precursors. Owing to the combined electronic effect and nanostructuring effect, our OLC/Co-N-C materials exhibit high bifunctional oxygen reduction/evolution reaction (ORR/OER) activity, showing a promising application in rechargeable Zn-air batteries. Experimental results are rationalized by theoretical calculations, showing that the curvature of graphitic carbon plays a vital role in promoting activities of meta-carbon atoms near graphitic N and ortho/meta carbon atoms close to pyridinic N.

11.
Small ; 16(20): e2001171, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32329197

RESUMO

Highly efficient and stable bifunctional electrocatalysts for oxygen reduction and evolution are essential for aqueous rechargeable Zn-air batteries, which require highly active sites as well as delicate structural design for increasing effective active sites and facilitating mass/electron transfer. Herein, a scalable and facile self-catalyzed growth strategy is developed to integrate highly active Co-N-C sites with 3D brush-like nanostructure, achieving Co-N-C nanobrushes with Co,N-codoped carbon nanotube branches grown on Co,N-codoped nanoparticle assembled nanowire backbones. Systematic investigations suggest that nanobrushes deliver significantly improved electrocatalytic activity compared with nanowire or nanotube counterparts and the longer nanotube branches give the better performance. Benefiting from the increase of accessible highly active sites and enhanced mass transfer and electron transportation, the present Co-N-C nanobrush exhibits superior electrocatalytic activity and durability when used as a bifunctional oxygen catalyst. It enables a rechargeable Zn-air battery with a high peak power density of 246 mW cm-2 and excellent cycling stability. These results suggest that the reported synthetic strategy may open up possibilities for exploring efficient electrocatalysts for diverse applications.

12.
J Assist Reprod Genet ; 37(12): 3025-3031, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33057910

RESUMO

PURPOSE: There is no consensus yet in the literature on an optimal luteinizing hormone (LH) level for human chorionic gonadotrophin (hCG) trigger timing in patients undergoing frozen-thawed embryo transfer (FET) with modified natural cycles (mNC). The objective of our study was to compare the clinical results of hCG trigger at different LH levels in mNC-FET cases. METHODS: This retrospective study was conducted in Istanbul Memorial Hospital ART and Genetics Center. A total of 1076 cases with 1163 mNC-FET cycles were evaluated. LH levels between the start of LH rise (15 IU/L) and LH peak level (> 40 IU/L) were evaluated. Cycles were analyzed in four groups: group A (n = 287) LH level on the day prior to the day of hCG; groups B, C and D, LH levels on the day of hCG: group B (n = 245) LH 15-24.9; group C (n = 253), LH 25-39.9; group D (n = 383) LH ≥ 40. Cycle outcomes in the four groups were compared. RESULTS: Subgroup analyses of mNC-FET groups showed that implantation, clinical and ongoing pregnancy rates, and pregnancy losses were not significantly different in patients with different LH levels on the day of hCG trigger. CONCLUSION: Our study suggests that hCG can be administered at any time between the start of LH rise (≥ 15 IU/L) and LH peak level (≥ 40 IU/L) without a detrimental effect on clinical outcome.


Assuntos
Gonadotropina Coriônica/administração & dosagem , Criopreservação/métodos , Transferência Embrionária/métodos , Hormônio Luteinizante/sangue , Indução da Ovulação/métodos , Adulto , Feminino , Humanos , Gravidez , Taxa de Gravidez , Estudos Retrospectivos
13.
J Clin Apher ; 34(6): 646-655, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31424127

RESUMO

BACKGROUND: Peripheral hematopoietic stem cell (HSC) collections are needed for autologous hematopoietic stem cell transplantation (HSCT). Since 2015, our institution has utilized a secondary chamber mononuclear cell (MNC) protocol on the Spectra Optia apheresis system. Recently, a new continuous mononuclear collection protocol (CMNC) was developed for the same device. As there is limited data available regarding the use of the CMNC protocol in children, we compared collection efficiency (CE2), side effects, and clinical feasibility between the two protocols in patients <18 years old. STUDY DESIGN AND METHODS: We prospectively collected clinical, laboratory, and technical collection data from HSC collection procedures performed with the Spectra Optia apheresis system utilizing the CMNC protocol. Data were compared to retrospectively collected data utilizing the MNC protocol. Data collection included donor demographics, precollection peripheral CD34+ cell counts, total CD34+ cells collected, collection efficiency, side effects, and collection product characteristics. RESULTS: A total of 96 HSC collection procedures were performed on 79 pediatric patients utilizing either the MNC (61 patients) or CMNC (18 patients) protocol. The collection efficiencies were comparable between MNC and CMNC cohorts (52.9% vs 54.9%, P = 0.711). Platelet loss was significantly lower in the CMNC cohort (P = 0.002), especially in children weighing <15 kg. Product volumes were higher with CMNC. No significant collection-related side effects were noted with either protocol. CONCLUSIONS: MNC and CMNC protocols have comparable collection efficiencies and are both feasible and safe for the use in children. Centers may choose between the methods depending on clinical needs.


Assuntos
Leucaférese/métodos , Adolescente , Antígenos CD34/sangue , Criança , Coleta de Dados/métodos , Mobilização de Células-Tronco Hematopoéticas/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Leucaférese/instrumentação , Leucócitos Mononucleares , Pediatria , Transplante Autólogo
14.
Nutr Res Rev ; 31(2): 291-301, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30033891

RESUMO

High carbohydrate intake and low-grade inflammation cooperate with insulin resistance and hyperandrogenism to constitute an interactive continuum acting on the pathophysiology of polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age characterised by oligo-anovulatory infertility and cardiometabolic disorders. The role of insulin in PCOS is pivotal both in regulating the activity of ovarian and liver enzymes, respectively involved in androgen production and in triggering low-grade inflammation usually reported to be associated with an insulin resistance, dyslipidaemia and cardiometabolic diseases. Although an acute hyperglycaemia induced by oral glucose loading may increase inflammation and oxidative stress by generating reactive oxygen species through different mechanisms, the postprandial glucose increment, commonly associated with the Western diet, represents the major contributor of chronic sustained hyperglycaemia and pro-inflammatory state. Together with hyperinsulinaemia, hyperandrogenism and low-grade inflammation, unhealthy diet should be viewed as a key component of the 'deadly quartet' of metabolic risk factors associated with PCOS pathophysiology. The identification of a tight diet-inflammation-health association makes the adoption of healthy nutritional approaches a primary preventive and therapeutic tool in women with PCOS, weakening insulin resistance and eventually promoting improvements of reproductive life and endocrine outcomes. The intriguing nutritional-endocrine connections operating in PCOS underline the role of expert nutritionists in the management of this syndrome. The aim of the present review is to provide an at-a-glance overview of the possible bi-directional mechanisms linking inflammation, androgen excess and carbohydrate intake in women with PCOS.


Assuntos
Androgênios/sangue , Glicemia/metabolismo , Dieta/efeitos adversos , Carboidratos da Dieta/efeitos adversos , Inflamação/complicações , Insulina/sangue , Síndrome do Ovário Policístico/complicações , Carboidratos da Dieta/administração & dosagem , Feminino , Humanos , Hiperandrogenismo/sangue , Hiperandrogenismo/complicações , Hiperinsulinismo/sangue , Hiperinsulinismo/complicações , Inflamação/sangue , Resistência à Insulina , Síndrome do Ovário Policístico/sangue
15.
J Clin Apher ; 33(3): 349-356, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29465755

RESUMO

BACKGROUND: An increasing demand for human lymphocytes require an efficient, reliable and reproducible lymphocyte process. Here, we compare the Spectra Optia® CMNC protocol with the Optia MNC platform in unmobilised donor lymphocyte collections. PURPOSE: To establish and compare the feasibility, efficiency, and practicability of the two apheresis protocols. METHODS: Data was collected prospectively from 60 non-cytokine stimulate donors who underwent a total of 64 T-cell collection procedures. Of these, 24 procedures were performed in the CMNC cohort and 40 procedures in the MNC cohort. All donors in the CMNC group were related; all donors in the MNC group were donors from a registry. Donor characteristics, procedure parameters and cellular product content were analysed and compared. RESULTS: Donor characteristics and full blood count results were comparable, except the median white blood cell count, which was higher in the CMNC cohort (6.87 vs. 5.58 ×109 /L, P < .005). This resulted in higher lymphocyte (1.95 vs. 1.57 ×109 /L, P < .009) and CD3+ cell counts (1476 vs. 1060/L, P < .02). A total blood volume processed of 2.0 resulted in i) run time (222 vs. 242 min), ii) product volume (192 vs. 183 ml), iii) platelet content (2140 vs. 1345 ×106 /ml, P < .003). CD3+ CE2 (%): 54.7 vs. 50.4. CONCLUSION: The CMNC and MNC protocols are reliable, efficient and comparable in performance parameters and cell composition of final product, respectively. One advantages of the CMNC protocol is the potential ability to tailor the cell composition of the final product accordingly to demands from cell processing laboratories.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Linfócitos T/citologia , Adulto , Remoção de Componentes Sanguíneos/normas , Doadores de Sangue , Protocolos Clínicos/normas , Citocinas , Humanos , Contagem de Leucócitos , Contagem de Plaquetas , Fatores de Tempo
16.
Transfus Med Hemother ; 45(5): 323-330, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30498410

RESUMO

BACKGROUND: There is an increasing demand for products containing mononuclear cells (MNCs) for cellular immune therapy. Hence, leukapheresis is increasingly performed in healthy volunteer donors. METHODS: We evaluated 147 low-volume leukapheresis procedures from 77 healthy non-cytokine-stimulated donors. Complete blood counts (CBCs) of the donors were measured before and directly after the procedures as well as from the MNC products. Follow-up CBCs were collected from donors within 21 days. RESULTS: The product hematocrit within a range from 1.2 to 6.0% did not correlate with the collection efficiency of any cell population or the granulocyte and platelet yield. There was a strong correlation between the CBC values before leukapheresis and the cell yield of lymphocytes and monocytes as well as a perfect negative correlation between cell recruitment and cell loss in all cell populations. Furthermore, we observed a significant decrease in the CBC values in all cell populations directly after leukapheresis, which recovered within a mean of 16.1 days (SD ± 2.1 days) and even showed a significant increase in granulocytes and platelets. CONCLUSION: Low-volume leukapheresis is feasible for the collection of MNCs in which the product hematocrit is negligible for the collection efficiency, cell yield, or contamination of residual cells under operational settings recommended by the manufacturer. Our data suggests that cell recruitment is regulated by the number of cells removed, which may also be the stimulus to induce granulo- and thrombopoiesis within the first days after leukapheresis.

17.
Cytotherapy ; 19(3): 433-439, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28034522

RESUMO

BACKGROUND AIMS: Umbilical cord blood (CB) is being used as a source of hematopoietic stem cells (HSCs) and immune cells to treat many disorders. Because these cells are present in low numbers in CB, investigators have developed strategies to expand HSCs and other immune cells such as natural killer (NK) cells. The initial step in this process is to enrich mononuclear cells (MNCs) while depleting unwanted cells. The manual method of MNC enrichment is routinely used by many centers; however, it is an open system, time-consuming and operator dependent. For clinical manufacturing, it is important to have a closed system to avoid microbial contamination. METHODS: In this study, we optimized an automated, closed system (Sepax) for enriching MNCs from cryopreserved CB units. RESULTS: Using Sepax, we observed higher recovery of total nucleated cells (TNC), CD34+ cells, NK cells and monocytes when compared to manual enrichment, despite similar TNC and CD34+ viability with the two methods. Even though the depletion of red blood cells, granulocytes and platelets was superior using the manual method, significantly higher CFU-GM were obtained in MNCs enriched using Sepax compared to the manual method. This is likely related to the fact that the automated Sepax significantly shortened the processing time (Sepax: 74 - 175 minutes versus manual method: 180 - 290 minutes). The use of DNAse and MgCl2 during the Sepax thaw and wash procedure prevents clumping of cells and loss of viability, resulting in improved post-thaw cell recovery. DISCUSSION: We optimized enrichment of MNCs from cryopreserved CB products in a closed system using the Sepax which is a walk away and automated processing system.


Assuntos
Separação Celular/instrumentação , Separação Celular/métodos , Eritrócitos/citologia , Sangue Fetal/citologia , Ficoll/química , Técnicas de Cultura de Células , Proliferação de Células , Sobrevivência Celular , Criopreservação , Eritrócitos/fisiologia , Citometria de Fluxo , Congelamento/efeitos adversos , Granulócitos/citologia , Granulócitos/fisiologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/fisiologia , Humanos , Monócitos/citologia , Monócitos/fisiologia
18.
Heart Vessels ; 32(9): 1099-1108, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28357515

RESUMO

The clinical features of patients with critical limb ischemia (CLI) who responded to angiogenesis using autologous peripheral blood mononuclear cell transplantation (PB-MNC) have not yet been fully characterized, and there are no useful predictors to judge the curative effect in the early period after PB-MNC. This study sought to clarify the clinical features and predictors in patients with CLI who were successfully treated using PB-MNC. 30 consecutive patients [arteriosclerosis obliterans: 24 patients, thromboangiitis obliterans: 6 patients] who were diagnosed with major amputation despite maximal medical therapy were enrolled in this study. The study endpoint was major amputation within 3 months after PB-MNC. The collected data were evaluated for correlation between patients with and without major amputation within 3 months after PB-MNC. Six patients underwent major amputation and 1 patient underwent minor amputation. In the patients with major amputation, transcutaneous oxygen tension before PB-MNC and transplanted CD34-positive cells were lower than those of patients without major amputation. In the patients with amputation, interleukin-6 (IL-6) continued to increase after the first PB-MNC, and basic fibroblast growth factor (bFGF) decreased within 3 days after the first PB-MNC. PB-MNC was useful for the patients who were managed for inflammation and who had revascularization of the upper-popliteal arteries and two of the infra-popliteal arteries by endovascular and/or surgical revascularization. Variation in IL-6 and bFGF in the early period after PB-MNC could be useful predictors for the requirement of amputation within 3 months after PB-MNC.


Assuntos
Transplante de Células/métodos , Isquemia/terapia , Leucócitos Mononucleares/transplante , Extremidade Inferior/irrigação sanguínea , Neovascularização Fisiológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia por Tomografia Computadorizada , Feminino , Seguimentos , Humanos , Isquemia/diagnóstico por imagem , Isquemia/fisiopatologia , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Autólogo , Resultado do Tratamento , Ultrassonografia
19.
Neurosurg Focus ; 42(4): E4, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28366053

RESUMO

Despite the success of numerous neuroprotective strategies in animal and preclinical stroke models, none have effectively translated to clinical medicine. A multitude of influences are likely responsible. Two such factors are inefficient recanalization strategies for large vessel occlusions and suboptimal delivery methods/platforms for neuroprotective agents. The recent endovascular stroke trials have established a new paradigm for large vessel stroke treatment. The associated advent of advanced mechanical revascularization devices and new stroke technologies help address each of these existing gaps. A strategy combining effective endovascular revascularization with administration of neuroprotective therapies is now practical and could have additive, if not synergistic, effects. This review outlines past and current neuroprotective strategies assessed in acute stroke trials. The discussion focuses on delivery platforms and their potential applicability to endovascular stoke treatment.


Assuntos
Sistemas de Liberação de Medicamentos , Fármacos Neuroprotetores/administração & dosagem , Acidente Vascular Cerebral/terapia , Trombectomia/métodos , Animais , Isquemia Encefálica/complicações , Serviços Médicos de Emergência , Humanos , Acidente Vascular Cerebral/etiologia
20.
Eur J Clin Invest ; 46(10): 853-63, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27513763

RESUMO

BACKGROUND: Several activities are attributed to antimicrobial peptides (AMPs), including bacterial killing, leucocyte recruitment and angiogenesis. Despite promises of advanced cellular therapies for treatment of diabetic foot ulcer, it is currently accepted that paracrine factors rather than cellular components are causative for the observed effects. Whether AMPs are present in the mononuclear cell (MNC) secretome (MNC-sec) of white blood cells that are beneficial in experimental wound healing is not known. MATERIALS AND METHODS: Antimicrobial activity of the secretomes of nonirradiated (MNC-sec) and γ-irradiated MNCs (MNC-sec rad) was analysed by microdilution assay. AMPs were determined by quantitative real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Whether human MNC-sec rad causes AMP secretion in vivo was examined in an experimental rat model. Image flow cytometry was used to determine the type of cell death induced in MNCs after exposure to γ-radiation. RESULTS: The antimicrobial activity assay revealed a bactericidal activity of MNC-sec rad and to a lesser degree also of MNC-sec. Image flow cytometry showed that γ-irradiation of MNCs induced early apoptosis followed mainly by necroptosis. RT-PCR and ELISA revealed a high abundance of different AMPs in the secretome of MNCs. In addition, human MNC-sec elicited an increase in de novo endogenous AMP production in rats in vivo. CONCLUSION: We provide evidence that the secretome of MNCs has direct and indirect positive effects on the immune defence system, including augmentation of antibacterial properties. Our data further suggest that necroptosis could play a key role for the release of paracrine factors and the therapeutic action of MNC-sec rad.


Assuntos
Anti-Infecciosos/farmacocinética , Peptídeos Catiônicos Antimicrobianos/farmacologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Leucócitos Mononucleares/metabolismo , Adolescente , Adulto , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Apoptose/efeitos da radiação , Morte Celular , Raios gama , Humanos , Leucócitos Mononucleares/fisiologia , Masculino , Ratos Sprague-Dawley , Adulto Jovem
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