Source Of Cells For Transplantation Research Articles

Risk Factors for Primary and Secondary Graft Failure in Allogenic Hematopoietic Cell Transplantation: A Single Center Study

Introduction: Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapy for high risk hematological diseases and sustained engraftment of the donor stem cells is essential for transplant success. Graft failure (GF) is a rare, but serious complication post allo-HCT. In the presented study we aimed to assess the incidence, risk factors in a single-center population and as well the impact on transplant outcome. Methods: Between 01 January 2015 and 31 December 2018, 557 patients underwent allo-HCT at our center. Data was collected retrospectively and updated in June 2019. Cases were included regardless of the underlying diagnosis, disease status prior to transplant, preparative regimen, or stem cell source. Primary graft failure was defined as failure to achieve an absolute neutrophil count (ANC) of >500/ µL by 28 days after bone marrow (BM) or peripheral blood stem cell (PB) transplantation. In contrast, secondary graft failure was defined as cytopenias after initial engraftment (ANC <500/µL), with (a) donor chimerism of less than 5% or (b) falling donor chimerism with intervention such as second transplant or donor lymphocyte infusion (DLI) or (c) patient death due to cytopenias, and fall in donor chimerism, even if chimerism was >5%. Exclusion criteria for diagnosis of GF were (a) disease relapse (b) graft versus host disease or (c) other causes of cytopenias such as, viral infections, or drug induced. Outcomes examined included overall survival (OS), cumulative incidence of GF, non-relapse mortality (NRM) and cause of death. Results: Baseline characteristics are summarized in (Table 1). GF was seen in 43 (7.7%) patients. Of these 43 patients, 9 (21%) had primary GF, and 34 (79%) had secondary GF. The cumulative incidence of GF overall (primary and secondary) is 1.6% (0.8- 3.0%) at day 100 and 6.5% (4.5-8.8%) at day 800. The median survival of patients following primary GF was 41 days versus 144 days in secondary GF. At one hundred days OS in primary GF was 22% and in secondary GF was 64%. The 1y and 2y OS for secondary GF was 33% and 28% respectively (Figure 1-A). Multivariable analysis demonstrated that the (a) diagnosis/transplant indication (MDS, myelofibrosis, lymphoma or non-malignant diseases) and (b) donor type (HLA-mismatched unrelated or haploidentical) were the only factors significantly associated with increased GF (Table 2). We determined the effect of more than one of these risk factors on the occurrence of graft failure as seen in (Figure 1-B). In the absence of any of the risk factors, the incidence of GF was 3.6%. If one risk factor was present, the incidence of GF was 9.9%, and if 2 risk factors were present, the incidence of GF was 24.5%. In primary GF, 5 patients underwent second allo-HCT. In secondary GF, 15 patients (44%) underwent a second allo-HCT and another 8 patients received donor lymphocyte infusion. All the patients with primary GF died because of graft failure and its associated complications. In secondary GF, 22 patients (51%) died, 30% of causes related to infections. Conclusions: Our study showed an increased risk for graft failure following the use of mismatched unrelated or haploidentical donors for diseases such as lymphoma, myelofibrosis, myelodysplastic syndrome and non-malignant diseases. As well, we found that a presence of two risk factors puts patients at clinically significant increased risk of graft failure. More intense conditioning therapy should be considered for patients with one but in particular two risk factors. Disclosures Michelis: CSL Behring: Other: Financial Support.

Deciphering retinal diseases through the generation of three dimensional stem cell-derived organoids: Concise Review.

Three‐dimensional (3D) retinal organoids, in vitro tissue structures derived from self‐organizing cultures of differentiating human embryonic stem cells or induced pluripotent stem cells, could recapitulate some aspects of the cytoarchitectural structure and function of the retina in vivo. 3D retinal organoids display huge potential for the investigation of the pathogenesis of monogenic hereditary eye diseases that are related to the malfunction or degeneration of photoreceptors or retinal ganglion cells by providing an effective in vitro tool with multiple applications. In combination with recent genome editing tools, 3D retinal organoids could also represent a reliable and renewable source of transplantable cells for personalized therapies. In this review, we describe the recent advances in human pluripotent stem cells‐derived retinal organoids, determination of their histoarchitecture, complexity, and maturity. We also discuss their application as a means to decipher the pathogenesis of retinal diseases, as well as the main drawbacks and challenges. stem cells 2019;37:1496–1504

Stem cell therapy for Parkinson's disease: safety and modeling.

For decades, clinicians have developed medications and therapies to alleviate the symptoms of Parkinson’s disease, but no treatment currently can slow or even stop the progression of this localized neurodegeneration. Fortunately, sparked by the genetic revolution, stem cell reprogramming research and the advancing capabilities of personalization in medicine enable forward-thinking to unprecedented patient-specific modeling and cell therapies for Parkinson’s disease using induced pluripotent stem cells (iPSCs). In addition to modeling Parkinson’s disease more accurately than chemically-induced animal models, patient-specific stem cell lines can be created, elucidating the effects of genetic susceptibility and sub-populations’ differing responses to in vitro treatments. Sourcing cell therapy with iPSC lines provides ethical advantages because these stem cell lines do not require the sacrifice of human zygotes and genetically-specific drug trails can be tested in vitro without lasting damage to patients. In hopes of finally slowing the progression of Parkinson’s disease or re-establishing function, iPSC lines can ultimately be corrected with gene therapy and used as cell sources for neural transplantation for Parkinson’s disease. With relatively localized neural degeneration, similar to spinal column injury, Parkinson’s disease presents a better candidacy for cell therapy when compared to other diffuse degeneration found in Alzheimer’s or Huntington’s Disease. Neurosurgical implantation of pluripotent cells poses the risk of an innate immune response and tumorigenesis. Precautions, therefore, must be taken to ensure cell line quality before transplantation. While cell quality can be quantified using a number of assays, a yielding a high percentage of therapeutically relevant dopaminergic neurons, minimal de novo genetic mutations, and standard chromosomal structure is of the utmost importance. Current techniques focus on iPSCs because they can be matched with donors using human leukocyte antigens, thereby reducing the severity and risk of immune rejection. In August of 2018, researchers in Kyoto, Japan embarked on the first human clinical trial using iPSC cell therapy transplantation for patients with moderate Parkinson’s disease. Transplantation of many cell sources has already proven to reduce Parkinson’s disease symptoms in mouse and primate models. Here we discuss the history and implications for cell therapy for Parkinson’s disease, as well as the necessary safety standards needed for using iPSC transplantation to slow or halt the progression of Parkinson’s disease.

Generation of human hepatic progenitor cells with regenerative and metabolic capacities from primary hepatocytes.

Hepatocytes are regarded as the only effective cell source for cell transplantation to treat liver diseases; however, their availability is limited due to a donor shortage. Thus, a novel cell source must be developed. We recently reported that mature rodent hepatocytes can be reprogrammed into progenitor-like cells with a repopulative capacity using small molecule inhibitors. Here, we demonstrate that hepatic progenitor cells can be obtained from human infant hepatocytes using the same strategy. These cells, named human chemically induced liver progenitors (hCLiPs), had a significant repopulative capacity in injured mouse livers following transplantation. hCLiPs redifferentiated into mature hepatocytes in vitro upon treatment with hepatic maturation-inducing factors. These redifferentiated cells exhibited cytochrome P450 (CYP) enzymatic activities in response to CYP-inducing molecules and these activities were comparable with those in primary human hepatocytes. These findings will facilitate liver cell transplantation therapy and drug discovery studies.

Accelerated photoreceptor differentiation of hiPSC-derived retinal organoids by contact co-culture with retinal pigment epithelium

Retinal organoids (ROs) derived from human-induced pluripotent stem cells recapitulate the three-dimensional structure of retina, mimic human retinal development, and provide cell sources for pre-clinical retinal transplantation. Retinal pigment epithelium (RPE) is crucial for normal outer retinal physiology, including phagocytosis of shed photoreceptor outer segments and secretion of neurotrophic and vasculotrophic growth factors. However, whether ROs-RPE co-culture can improve the differentiation of photoreceptors in ROs in vitro remains unknown. Herein, primary mouse RPE cells were contact co-cultured with ROs at different time points. Our results revealed that the RPE cells accelerated photoreceptor differentiation in ROs, as the cross talk between the RPE and ROs promoted the stage specific expression of photoreceptor markers at different differentiation stages. Thus, we established an improved co-culture system based on modeling of human retina-RPE dynamics during retinogenesis for the evaluation of ocular therapies.

G-CSF-Mobilized Blood and Bone Marrow Grafts as the Source of Stem Cells for HLA-Identical Sibling Transplantation in Patients with Thalassemia Major.

As an inherited anemia, thalassemia major (TM) is currently only curable with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here we report an allo-HSCT protocol for patients with TM who received a combination of granulocyte colony-stimulating factor-primed bone marrow and peripheral blood stem cells (G-BM & PBSCs) from a matched sibling donor (MSD). The conditioning regimen consisted of i.v. busulfan, cyclophosphamide, fludarabine, and antithymocyte globulin. Chimerism analysis was performed for all patients. Immunosuppressive treatment was terminated if rejection was suspected, and donor lymphocyte infusion was administered once no response was observed. A total of 184 patients with TM were enrolled in the study between July 2007 and July 2018. The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 13.1%, and that of moderate or severe chronic GVHD was 5.7%. The cumulative incidence of graft rejection was .6%. In the total cohort, the 3-year overall survival, thalassemia-free survival, and GVHD-free, relapse-free survival were 97.8%, 97.3%, and 89.5%, respectively. Collectively, our results indicate that G-BM & PBSCs from an MSD is be a good stem cell source for patients with TM undergoing allo-HSCT.

PB2387 CD56 BRIGHT/CD16‐ NATURAL KILLER CELLS COUNTS ARE HIGHER IN THE UMBILICAL CORD BLOOD THAN IN THE PERIPHERAL BLOOD FROM ADULTS

Background:Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells for allogeneic transplantation in the absence of compatible donor. UCB transplantation has lower incidence of chronic graft versus host disease (GvHD) but is associated with slower engraftment and slower immune reconstitution as compared to other sources. Dendritic cells (DC) and Natural Killer cells (NK) play a central role in the development of GVHD, the graft versus leukemia (GvL) effect, and in the control of infectious complications.Aims:To compare the absolute counts and frequencies of monocytes, B lymphocytes, T cells, NK cells and DC and their subsets in samples from UCB and PB.Methods:We quantified by multiparametric flow cytometry monocytes, B cells, T cells, NK cells and DC, including their subsets, in UCB samples from 54 healthy newborns and 25 peripheral blood (PB) samples from healthy adult volunteers [median age 33 years (range 18 to 66 years old); 15 (60%) male]. Fresh EDTA‐anticoagulated PB or UCB samples were collected and processed in up to 24 hours, using an 8‐color monoclonal antibodies panel (CD16 FITC/ CD56 & CD4 PE/ CD11c PerCP Cy5.5/ CD8 & CD19 PC7/ CD123 APC/ CD3 & CD14 APC‐H7/ HLA‐DR Pac Blue/ CD45 OC‐515), by stain‐lyse‐wash method. Acquisition was performed through FACSCANTOII flow cytometer and FACsDIVA® software (BDB‐ San Jose, CA). For data analysis Infinicity® software (Cytognos, SL) was used. NK cells (CD3‐, CD19‐, CD14‐, and CD56+), were classified as CD56brightCD16− or CD56dimCD16bright. Monocytes (CD45+, CD11c+, and HLA‐DR+) were classified as: classic (CD14++CD16‐), intermediate (CD14++CD16+) and non‐classical (CD14dimCD16++). Dendritic cells (HLA‐DR++, CD3‐, CD19‐, CD14‐, and CD56‐) were classified as pDC (CD123+/ CD11c‐), and mDC (CD123‐/ CD11c++). B cells were identified by CD19+ and absence of T and monocytic line markers. Comparisons between UCB and PB were performed using Mann‐Whitney test through SPSS version 21.0 (SPSS Inc., Chicago, IL). P value of <.05 was considered significant.Results:In the UCB samples, as compared to the PB samples, there were higher counts of NK CD56brightCD16− NK cells (median 0.24 × 108/L vs. 0.12 × 108/L, respectively, P < 0.0001), NK CD56dimCD16bright NK cells (median 4.46 × 108/L vs. 2.59 × 108/L, respectively, P = 0.001), and plasmacytoid dendritic cells (pDC, median 0.08 × 108/L vs. 0.06 × 108/L, respectively, P = 0.03). However, non‐classical monocytes counts were lower in UCB than in PB (We also observed lower counts of non‐classical monocytes (0.24 × 108/L vs. 0.51 × 108/L, respectively, p < .0001).Summary/Conclusion:In conclusion, our results show there were higher counts of NK cells and pDC and lower counts of non‐classical monocytes in UCB than in PB from healthy individuals. These findings might explain the lower incidence and severity of chronic GVHD although maintaining the GVL effect in UCB transplants recipients as compared to other stem cell sources.

Application of high-throughput next-generation sequencing for HLA typing of DNA extracted from postprocessing cord blood units.

Cord blood has become an acceptable source of hematopoietic stem cells for transplantation. HLA plays a major role in hematopoietic stem cell transplantation (HSCT). Typing of cord blood samples for HLA alleles has been performed based on the serological and molecular methods. However, with the advent of next-generation sequencing technology, HLA typing becomes more accurate and unambiguous (upto intron level). Contamination of cord blood cells with erythropoietic cells poses a challenge in DNA extraction and downstream application. In the present study, DNA extracted from buffy coat of cord blood samples was typed for HLA-A, -B, -C, DRB1, and DQB1 alleles by Illumina miniseq and the sequences were aligned, phased, and mapped by MIA FORA software algorithms. Most frequent alleles found were HLA A*01:01:01 (17%), A*24:02:01 (15.1%), A*11:01:01 (13.6%), B*40:06:01 (10.7%), C*06:02:01 (17.7%), C*04:01:01 (14.2%), C*15:02:01 (11.4%), C*07:02:01 (10.7%), DRB1*07:01:01 (15.9%), DRB1*10:01:01 (10.2%), DQB1*06:01:01 (17.4%), DQB1*05:01:01 (12.4%), and DQB1*05:03:01 (10.4%). One null allele (A*24:11N), two novel alleles in B loci and three rare alleles (B*40:06:04, B*51:01:05, and C*01:44) were also identified in the present study. This study shows that high-throughput, unambiguous (third-field resolution) HLA typing can be performed on cord blood samples. In order to preserve the precious sample for future use, minimal amount of cord blood samples (postprocessing) could be used for HLA typing purpose.

What will Become of the Taxpayer Investment in Public Cord Blood Stem Cell Banking?

Cord Blood (CB) is a unique and readily available source of hematopoietic stem cells for transplantation. CB also contains other types of stem cells, including endothelial stem cells and mesenchymal stem cells, that may prove useful in non-traditional clinical uses. Genetic and molecular analyses have demonstrated that CB stem cells lie somewhere between mature stem cells like those found in Bone Marrow (BM), and fetal stem cells. After 25 years of clinical experience, CB is now used in the same fashion as BM for all typical malignant and genetic diseases treated by bone marrow transplant. Due to the establishment of CB banks in the US and abroad, more than 35,000 CB transplants have been performed over the past 25 years. An average of 700-800 CB transplants are performed annually. In addition, CB is now used more frequently for regenerative medicine and tissue engineering applications. At first glance, it seems that everything could not be better with the public cord blood banks and the use of their samples in the clinic. However, a recent report by the Rand Corp. reviewed the US national cord blood stem cell banking program and detailed many ongoing problems. However, some details were omitted from the report that would shed some light on the causes of many of the problems. This paper will summarize the status of the public cord blood stem cell banking program in the US, detail the problems associated with the program that could jeopardize its existence and suggest possible solutions to resolve these issues.

Induced differentiation and molecular characterization of monocyte-derived multipotential cells (MOMCs) generated from commonly discarded leukapheresis filters

Background & Aim Μonocyte-derived multipotential cells (MOMCs), easily isolated from the peripheral blood, include progenitors capable of differentiating into endothelial lineages in a specific permissive environment and thus represent an autologous transplantable cell source for therapeutic neovasculogenesis (Kuwana M et al, 2012). Methods, Results & Conclusion discarded leukapheresis filters (T.P.H. Meyer et al, 2005)and estimate the expression of several stem cell factors that play a key role in their pluripotency and differentiation capacity. A leukocyte elution medium composed of Citrate phosphate dextrose (CPD), hypertonic SAGM and Phosphate Buffered Saline was prepared and used for back-flushing of the filters, opposite to the primary blood flow during the leukocyte depletion step. Upon centrifugation in density gradient, mononuclear cells were collected and subsequently incubated in 37οC 5% CO2conditions for 10 days in poly-L-lysine+gelatin coated plates in the presence of 50 ng/ml SDF-1a chemotactic factor enabling the MOMCs generation. Aiming the characterization of the harvested cells, flow cytometry was performed for the detection of typical surface marker expression (CD45, CD14, CD34, Collagen type I and CD184). The induced differentiation capacity of MOMCs towards bone and endothelium in specific culture mediums was estimated via alizarin red staining and flow cytometry, respectively. Finally, the expression levels of genes related with self-renewal and differentiation were estimated with Real-time PCR. The generated MOMCs were characterized by high expression of the CD45/CD14/CD34/CD184/Col I markers while progressively lost their native markers and gained endothelial or bone features upon induced differentiation. The MOMCs expressed several stem cell factors like Nanog, Oct4, c-Myc, Sox2, Klf4, Sall4, ESRRB and ZNF214. All these factors are responsible to activate the networks related with the pluripotency, differentiation and reprogramming of cells while are highly expressed in embryonic stem cells. To conclude, we successfully optimized conditions to elute leukocytes adsorbed to leukapheresis filters resulting in leukocyte suspensions collection for multiple uses. The easy and quick generation of MOMCs from monocytes derived from leukapheresis filters, makes them potential candidates for future therapeutic application in tissue regeneration.

Comparison of the efficacy of different cell sources for transplantation in total limbal stem cell deficiency.

The purpose of this study was to compare the efficacy of allogeneic cultured limbal epithelial transplantation (ACLET) and cultivated oral mucosal epithelial transplantation (COMET) in treating total limbal stem cell deficiency (LSCD). In this retrospective cohort study, 73 patients (76 eyes) with total LSCD, including 41 patients (42 eyes) treated with ACLET and 32 patients (34 eyes) receiving COMET, were evaluated. The age, gender and injury cause of all patients were recorded. The mean follow-up was 23.3 ± 9.9months in the ACLET group and 16.1 ± 5.8months in the COMET group. A higher incidence of persistent epithelial defect was observed after COMET (P = 0.023). The overall ocular surface grading scores were all lower in the ACLET group than in the COMET group at 3, 6, and 12months after surgery and the last follow-up. Kaplan-Meier survival curve analysis demonstrated a significantly higher success rate of ACLET (71.4%), compared with that of COMET (52.9%; P = 0.043). The risk of graft failure was higher in patients with entropion and trichiasis, incomplete eyelid closure and treated with COMET. The graft failure risk rate after COMET was 3.5 times higher than that of ACLET. For total LSCD patients, ACLET should be prioritized, since limbal epithelial cells have better ability to maintain corneal epithelial integrity and ocular surface stability and benefit the ocular surface when compared with oral mucosal epithelial cells. Preoperative and postoperative eyelid abnormalities should be corrected as early as possible.

Differentiation Capacity of Monocyte-Derived Multipotential Cells on Nanocomposite Poly(e-caprolactone)-Based Thin Films.

Μonocyte-derived multipotential cells (MOMCs) include progenitors capable of differentiation into multiple cell lineages and thus represent an ideal autologous transplantable cell source for regenerative medicine. In this study, we cultured MOMCs, generated from mononuclear cells of peripheral blood, on the surface of nanocomposite thin films. For this purpose, nanocomposite Poly(e-caprolactone) (PCL)-based thin films containing either 2.5wt% silica nanotubes (SiO2ntbs) or strontium hydroxyapatite nanorods (SrHAnrds), were prepared using the spin-coating method. The induced differentiation capacity of MOMCs, towards bone and endothelium, was estimated using flow cytometry, real-time polymerase chain reaction, scanning electron microscopy and fluorescence microscopy after cells' genetic modification using the Sleeping Beauty Transposon System aiming their observation onto the scaffolds. Moreover, Wharton's Jelly Mesenchymal Stromal Cells were cultivated as a control cell line, while Human Umbilical Vein Endothelial Cells were used to strengthen and accelerate the differentiation procedure in semi-permeable culture systems. Finally, the cytotoxicity of the studied materials was checked with MTT assay. The highest differentiation capacity of MOMCs was observed on PCL/SiO2ntbs 2.5wt% nanocomposite film, as they progressively lost their native markers and gained endothelial lineage, in both protein and transcriptional level. In addition, the presence of SrHAnrds in the PCL matrix triggered processes related to osteoblast bone formation. To conclude, the differentiation of MOMCs was selectively guided by incorporating SiO2ntbs or SrHAnrds into a polymeric matrix, for the first time.

Advanced Functional Biomaterials for Stem Cell Delivery in Regenerative Engineering and Medicine

AbstractStem cell–based therapies can potentially regenerate many types of tissues and organs, thereby providing solutions to a variety of diseases and injuries. However, acute cell death, uncontrolled differentiation, and low functional engraftment yields remain critical obstacles for clinical translation. Advanced functional biomaterial scaffolds that can deliver stem cells to the targeted tissues/organs and promote stem cell survival, differentiation, and integration to host tissues may potentially transform the clinical outcome of stem cell–based regenerative therapies. In this review, the authors briefly summarize sources of stem cells for transplantation, present the current state of the art in biomaterial design for stem cell delivery, and provide critical analysis for existing materials. Applications to the cardiovascular, neural, and musculoskeletal systems are highlighted with recent nonclinical studies and clinical trials. The authors also discuss how advances in biomaterials research can contribute to regenerative medicine research and stem cell therapies.

Cell Therapies for Parkinson's Disease.

Cell Therapies for Parkinson's Disease.

Platelet-rich plasma improves therapeutic effects of menstrual blood-derived stromal cells in rat model of intrauterine adhesion

BackgroundIntrauterine adhesion (IUA) is a major cause of female secondary infertility. We previously demonstrated that menstrual blood-derived stromal cell (MenSC) transplantation helped severe IUA patients have pregnancy and endometrium regeneration. We also initiated platelet-rich plasma (PRP) acted as a beneficial supplement in MenSC culturing and a potential endometrial receptivity regulator. Here, we investigated the therapeutic effect of combined transplantation of MenSCs with PRP in rat IUA models and the mechanisms of MenSCs in endometrium regeneration.MethodsRat IUA models were established by intrauterine mechanical injured. Nine days later, all rats were randomly assigned to four groups received different treatment: placebo, MenSC transplantation, PRP transplantation, and MenSCs + PRP transplantation. The traces of MenSCs were tracked with GFP label. Endometrial morphology and pathology, tissue proliferation, inflammation, pregnancy outcomes, and mechanism of MenSCs in the regeneration of endometrium were investigated.ResultsNotably, at days 9 and 18 post-treatment, MenSC transplantation significantly improved endometrial proliferation, angiogenesis, and morphology recovery and decreased collagen fibrosis and inflammation in the uterus. MenSCs had lesion chemotaxis, colonized around the endometrial glands. Gene expression of human-derived secretory protein IGF-1, SDF-1, and TSP-1 was detected in the uterus received MenSCs at day 18. The three treatments can all improve fertility in IUA rats. Moreover, gene expressions of cell proliferation, developmental processes, and other biological processes were induced in MenSC transplantation group. Hippo signaling pathway was the most significantly changed pathway, and the downstream factors CTGF, Wnt5a, and Gdf5 were significantly regulated in treatment groups. PRP enhanced these parameters through a synergistic effect.ConclusionsIn summary, MenSCs could effectively improve uterine proliferation, markedly accelerate endometrial damage repairment and promote fertility restoration in IUA rats, suggesting a paracrine restorative effect and Hippo signaling pathway stimulation. Our results indicate MenSCs, a valuable source of cells for transplantation in the treatment intrauterine adhesion. Combined with PRP, this cell therapy was more effective.

Induction of Rod and Cone Photoreceptor-Specific Progenitors from Stem Cells.

Retinal degeneration includes a variety of diseases for which there is no regenerative therapy. Cellular transplantation is one potential approach for future therapy for retinal degeneration, and stem cells have emerged as a promising source for future cell therapeutics. One major barrier to therapy is the ability to specify individual photoreceptor lineages from a variety of stem cell sources. In this review, we focus on photoreceptor genesis from progenitor populations in the developing embryo and how this understanding has given us the tools to manipulate cultures to specific unique rod and cone lineages from adult stem cell populations. We discuss experiments and evidence uncovering the lineage mechanisms at play in the establishment of fate-specific rod and cone photoreceptor progenitors. This may lead to an improved understanding of retinal development in vivo, as well as new cell sources for transplantation.

Evolution of Peripheral Blood Stem Cell Transplantation.

Blood-derived progenitors have become the predominant source of hematopoietic stem cells for clinical transplantation. The main advantages compared to the bone marrow are as follows: harvesting blood stem cells is less painful for the donor, utilizes much less resources such as operating theater time and general anesthesia, and, above all, is associated with significantly accelerated reconstitution. The latter has ultimately improved patient safety as a consequence of significantly shortened aplastic phase and hence reduced morbidity and mortality after transplantation. Basic and translational research efforts in the 1960s to the mid-1980s have made the first blood stem cell transplantation in Heidelberg in 1985 possible. Diverse groups around the world have contributed to incremental knowledge that culminated in the first successful attempts in blood stem cell transplantation. These efforts have spawned modern research into stem cell biology and the immune modulatory effects of allogeneic transplantations.

Umbilical cord blood quality and quantity: Collection up to transplantation.

Umbilical cord blood (UCB) is an attractive source of hematopoietic stem cells for transplantation in some blood disorders. One of the major factors that influence on transplantation fate is cord blood (CB) cell count, in addition to human leukocyte antigen similarity and CD34+ cell number. Here, we review the factors that could effect on quality and quantity of CBUs. Relevant English-language literatures were searched and retrieved from PubMed using the terms: CB, quality, collection, and transplantation. The numbers of total nucleated cells (TNCs) and CD34+ cells are good indicators of CB quality because they have been associated with engraftment; thereby, whatever the TNCs in a CB unit (CBU) are higher, more likely they led to successful engraftment. Many factors influence the quantity and quality of UCB units that collect after delivery. Some parameters are not in our hands, such as maternal and infant factors, and hence, we cannot change these. However, some other factors are in our authority, such as mode of collection, type and amount of anticoagulant, and time and temperature during collection to postthaw CBUs and freeze-and-thaw procedures. By optimizing the CB collection, we can improve the quantity and quality of UCB for storage and increase the likelihood of its use for transplantation.

Mobilization and Collection of Peripheral Blood Stem Cells in Adults: Focus on Timing and Benchmarking.

Peripheral blood stem cells (PBSCs) are preferentially used as a hematopoietic stem cell source for autologous blood stem cell transplantation (ABSCT) upon high-dose chemotherapy (HDT) in a variety of hemato-oncologic diseases. As a prerequisite, hematopoietic stem cells have to be mobilized into the peripheral blood (PB) and collected by leukapheresis (LP). Despite continuous improvements, e.g., the introduction of plerixafor, current challenges are the further optimization regarding the leukapheresis procedure, preventing collection failures, as well as benchmarking and harmonization of mobilization approaches between institutions.This chapter summarizes the current PBSC mobilization and collection approaches and is focusing on timely orchestration of mobilization therapy, granulocyte colony-stimulating factor (G-CSF) application, and peripheral blood (PB) CD34+ cell assessment. Moreover, strategies for prediction and performance assessment of the PBSC collection yield are discussed.

The collagen scaffold supports hiPSC-derived NSC growth and restricts hiPSC.

The human induced pluripotent stem cells (hiPSC) are one of the promising candidates as patient specific cell source for autologous transplantation or modeling of diseases. The collagen (Col) scaffolds have been shown suitable to create in vitro biomimetic microenvironment for human neural stem cells, but their ability to accommodate stem cells at different stages of neural differentiation has not been verified yet. In this paper we compare lineage related hiPSC during neural differentiation for their ability to colonize Col scaffold. We have also focused on modification of collagen physicochemical properties with improved mechanical and thermal stability, without loss of its biological activity. The hiPSC expressing markers of pluripotency (OCT4, SOX2, NANOG) after neural commitment are NESTIN, GFAP, PDGFR alpha, beta- TUBULIN III, MAP-2, DCX, GalC positive. We have shown, that Col scaffold was not preferable for hiPSC culture, while the neurally committed population after seeding on Col scaffolds revealed good adhesion, viability, proliferation, along with sustaining markers of neuronal and glial differentiation. The Col scaffold-based 3D culture of hiPSC-NSCs may serve as a research tool for further translational studies.