Latest Umbilical Blood Research

[Blood mesenchymal stem cell culture from the umbilical cord with and without Ficoll-Paque density gradient method]
Primary Author: Rosa Sayoko Kawasaki-Oyama
Primary Author: Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brasil. rosa@braile.com.br
Date Published: 2008 08 22
Abstract: OBJECTIVES: Implantation of cell separation and mesenchymal stem cell culture techniques from human umbilical cord blood with and without using the Ficoll-Paque gradient density method (d=1.077 g/ml). METHODS: Ten samples of the umbilical cord blood obtained from full-term deliveries were submitted to two different procedures of mesenchymal stem cell culture: a) Method without the Ficoll-Paque density gradient, which concentrates all nucleated cells; b) Method with the Ficoll-Paque density gradient, which selects only low-density mononuclear cells. Cells were initially plated into 25 cm(2) cultures flasks at a density of 1 x 10(7) nucleated cells/cm(2) and 1 x 10(6) mononuclear cells/cm(2). RESULTS: It was obtained 2-13 x 10(7) (median = 2.35 x 10(7)) nucleated cells/cm(2) by the method without the Ficoll-Paque gradient density, and 3.7-15.7 x 10(6) (median = 7.2 x 10(6)) mononuclear cells/cm(2) by the method with the Ficoll-Paque gradient density. In all cultures adherent cells were observed 24 hours after being cultured. Cells presented fibroblastoid and epithelioid morphology. In most of the cultures, cell proliferation occurred in the first week, but after the second week only some cultures - derived from the method without the Ficoll-Paque gradient density-maintained the growth rate reaching confluence. Those cultures were submitted to trypsinization with 0.25% trypsin/EDTA solution and cultured for two to three months. CONCLUSION: In the samples analyzed, cell separation and mesenchymal stem cell culture techniques from human umbilical cord blood by the method without the Ficoll-Paque density gradient was more efficient than the method with the Ficoll-Paque density gradient.

[Large scale expansion of hematopoietic progenitor cells from umbilical cord blood by magnet stirred culture system.]
Primary Author: Hua-Xin Duan
Primary Author: Department of Hematology, The First Guangzhou Municipal People Hospital, Guangzhou Medical College, Guangzhou 510180, Guangdong Province, China.
Date Published: 2008 08 22
Abstract: The aim of this study was to expand hematopoietic progenitor cells at large scale by magnet stirred culture system. Mononuclear cell from umbilical cord blood were cultured in serum-free medium with stem cell factor, FIT-3 ligand and thrombopoietin. Firstly, the role of magnet on cell growth and colony-forming was studied by static culture on 0, 25 and 50 mT. Then the expansion multiple of cells, colony-forming and expression of surface markers were studied in magnet stirred culture by cell counting, colony-forming assay and flow cytometry. The results indicated that there was no difference in multiple of total cell expansion and numbers of hematopoietic colonies between 0, 25 and 50 mT groups and spinner groups (all p > 0.05). After 7 day cultures, the multiple of total cell expansion in magnet stirred culture was higher than that in static culture (p < 0.01). The numbers of CFU-GM (colony-forming unit-granulocyte/macrophage) and CFU-E (erythroid colony forming unit) in magnet stirred culture were higher than those in static culture, (p < 0.05). The primitive cells (CD34(+), CD34(+)/CD38(-) or CD133(+)) of the expanded cells in magnet stirred culture were less than those in static culture (p < 0.05). However, the CD184(+) or CD62L(+) expanded cells were more than that in static culture (p < 0.05). It is concluded that magnet stirred culture favors the expansion of hematopoietic progenitor cells. The results will be finally confirmed in further in vivo experiments and clinical applications.

Tendon repair through stem cell intervention: Cellular and molecular approaches.
Primary Author: Richard Bullough
Primary Author: Department of Trauma and Orthopaedic Surgery, Keele University Medical School, Keele, Stoke on Trent.
Date Published: 2008 8 22
Abstract: Tendon injuries are common in either the workplace or sport activities, with some 3 to 5 million tendon and ligament injuries occurring annually worldwide. Management of tendon injury currently follows two routes: Conservative (rehabilitation and pain relief), or surgical. Irrespective of which of these primary treatment routes are followed, even if healing does occur, it may not result in a full gain of function. The inability of the tendon to self-repair and the relative inefficiency of current treatment regimens suggest that identifying alternative strategies is a priority. One such alternative is the use of stem cells to repair damage, either through direct application or in conjunction with scaffolding. We describe the current state of the art in terms of: (i) Molecular markers of tendon development, (ii) stem cell applicability to human tendon repair, (iii) scaffolding for in vitro tendon generation, and (iv) chemical/molecular approaches to both induce stem cell differentiation into tenocytes and maintain their proliferation in vitro.

Bendamustine, but not fludarabine, exhibits a low stem cell toxicity in vitro.
Primary Author: M Schmidt-Hieber
Primary Author: Medizinische Klinik III (Hämatologie, Onkologie und Transfusionsmedizin), Charité, Campus Benjamin Franklin, Hindenburgdamm 30, 12200, Berlin, Germany, martin.schmidt-hieber@charite.de.
Date Published: 2008 8 22
Abstract: PURPOSE: We investigated the in vitro toxicity of bendamustine and fludarabine to hematopoietic progenitors and stem cells from healthy donors. METHODS: Clonogenic agar colony assays, non-clonogenic long-term liquid cultures (LTC) and apoptosis assays were used to assess the cytotoxicity of both the agents. RESULTS: Total colony-forming units (CFU) were more sensitive to fludarabine than to bendamustine in agar colony assays (IC(50) 0.7 muM/L and 8.5 muM/L, respectively). Using the Bliss independence model and combining the two agents yielded additive inhibition of progenitors. Non-clonogenic assays, including LTC and an apoptosis assay detecting activated caspases showed that stem cells are characterized by low sensitivity to bendamustine. In contrast, fludarabine strongly inhibited the viability and growth of stem cells in LTC. CONCLUSIONS: Our data show that bendamustine is characterized by lower in vitro toxicity to hematopoietic progenitors and stem cells than fludarabine and might thus be preferable in regimens prior to stem cells apheresis.