Substitution Of Fetal Bovine Serum Research Articles

Xenobiotic-Free Medium Guarantees Expansion of Adipose Tissue-Derived Canine Mesenchymal Stem Cells Both in 3D Fibrin-Based Matrices and in 2D Plastic Surface Cultures.

Mesenchymal stem cells (MSCs) have been recently introduced in veterinary medicine as a potential therapeutic tool for several pathologies. The large-scale in vitro expansion needed to ensure the preparation of a suitable number of MSCs for clinical application usually requires the use of xenogeneic supplements like the fetal bovine serum (FBS). The substitution of FBS with species-specific supplements would improve the safety of implanted cells, reducing the risk of undesired immune responses following cell therapy. We have evaluated the effectiveness of canine adipose tissue-derived stromal vascular fraction (SVF) and MSCs (ADMSCs) expansion in the presence of canine blood-derived supplements. Cells were cultured on traditional plastic surface and inside a 3D environment derived from the jellification of different blood-derived products, i.e., platelet-poor plasma (PPP), platelet-rich plasma (PRP), or platelet lysate (PL). PPP, PRP, and PL can contribute to canine ADMSCs in vitro expansion. Both allogeneic and autologous PPP and PL can replace FBS for ADMSCs culture on a plastic surface, exhibiting either a similar (PPP) or a more effective (PL) stimulus to cell replication. Furthermore, the 3D environment based on homospecific blood-derived products polymerization provides a strong stimulus to ADMSCs replication, producing a higher number of cells in comparison to the plastic surface environment. Allogeneic or autologous blood products behave similarly. The work suggests that canine ADMSCs can be expanded in the absence of xenogeneic supplements, thus increasing the safety of cellular preparations. Furthermore, the 3D fibrin-based matrices could represent a simple, readily available environments for effective in vitro expansion of ADMSCs using allogeneic or autologous blood-products.

Optimization of activin-A: a breakthrough in differentiation of human induced pluripotent stem cell into definitive endoderm.

The first step in differentiation of pluripotent stem cell toward endoderm-derived cell/organ is differentiation to definitive endoderm (DE) which is the central issue in developmental biology. Based on several evidences, we hypothesized that activin-A optimization as well as replacement of fetal bovine serum (FBS) with knockout serum replacement (KSR) is important for differentiation of induced pluripotent stem cell (iPSC) line into DE. Therefore, a stepwise differentiation protocol was applied on R1-hiPSC1 cell line. At first, activin-A concentration (30, 50, 70 and 100ng/ml) was optimized. Then, substitution of FBS with KSR was evaluated across four treatment groups. The amount of differentiation of iPSC toward DE was determined by quantitative gene expression analyses of pluripotency (NANOG and OCT4), definitive endoderm (SOX17 and FOXA2) and endoderm-derived organs (PDX1, NEUROG3, and PAX6). Based on gene expression analyses, the more decrease in concentrations of activin-A can increase the differentiation of iPSC into DE, therefore, 30ng/ml activin-A was chosen as the best concentration for the differentiation of R1-hiPSC1 line toward endoderm-derived organ. Moreover, complete replacement of FBS with gradually increased KSR improved the differentiation of iPSC toward DE. For this reason, the addition of 0% KSR at day 1, 0.2% at day 2 and 2% for the next 3days was the best optimal protocol of the differentiation of iPSC toward DE. Overall, our results demonstrate that optimization of activin-A is important for differentiation of iPSC line. Furthermore, the replacement of FBS with KSR can improve the efficiency of iPSC differentiation toward DE.

The Effect of Follicular Fluid on the Proliferation and Osteoblastic Differentiation of Human Bone Marrow Mesenchymal Stem Cells

Background and Aims: Bone marrow-derived mesenchymal stem cells (BM-MSCs) are a well-known source of multipotent adult stem cells. Despite using different methodologies of MSCs preparing for clinical applications, the top safest procedure to manipulate these cells, has not yet been determined. Recently, ex-vivo expansion of MSCs for their subsequent implantation, using some biological product, is suggested instead of fetal bovine serum (FBS). Previous studies have shown the effect of follicular fluid (FF) (a dynamic fluid in ovarian follicle) as an additive component in cell culture. Hence, this study aimed to decipher its role on the human BM-MSC proliferation.Materials and Methods: In this study, BM-MSCs at 3rd passage were cultivated in the presence of 20% FF (group I), 10% FF+ FBS 10% (group II) and FBS 20% as control group. The capacity of proliferation as calculating population doubling times and gene expression levels of stem cell factor, stromal cell-derived factor 1, and transforming growth factor beta were analyzed in osteogeneic media to examine the impacts of FF on osteogenesis of MSCs.Results: Our results corroborated an up-regulatory effect of FF on the proliferation of BM-MSCs by shorter population doubling times in the group II of treated cells and an increase in gene expression level of osteocalcin and transforming growth factor beta in the presence of higher concentrations of FF in cell culture FF 20% and 10%, respectively.Conclusions: FF is a potent mitogen for cell proliferation. FF may be an efficient substitution of FBS in ex-vivo cell culture, eliminating zoonotic infections and immunological reactions.

Comparative Effect of Human Platelet Derivatives on Proliferation and Osteogenic Differentiation of Menstrual Blood-Derived Stem Cells

Menstrual blood has been recognized as an easily accessible and inexpensive source of stem cells, in recent years. To establish a safe and efficient protocol for development of menstrual blood-derived stem cells (MenSCs) into osteoblasts, the effect of substitution of fetal bovine serum (FBS) with human platelet derivatives (HPDs) was evaluated during proliferation and osteogenic differentiation of MenSCs. To this aim, parallel experiments were carried out on cultured MenSCs in the presence of platelet-rich plasma, platelet-poor plasma, platelet gel supernatant, or human platelet releasate (HPR), and compared with cells cultured in conventional growth medium containing FBS. There was no significant difference between growth curves of cultured MenSCs in presence of different fortified media. However, the MenSCs demonstrated variant differentiation patterns in response to FBS replacement with HPDs. Mineralization, as judged by Alizarin red staining, was significantly higher in cells differentiated in the presence of HPR compared to cells that were fortified with other medium supplements. A greater osteocalcin production level, alkaline phosphatase activity, and mRNA expression of osteogenic-specific genes in differentiated MenSCs under HPR condition further confirmed our previous findings. Based on our data, FBS substitution by HPDs not only allows for successful MenSCs proliferation, but also promotes MenSCs development into osteoblasts. The effectiveness of HPR on osteogenic differentiation of MenSCs represents an important novel step toward safe and applied stem cell therapy of bone diseases.

Osteogenic Differentiation of Stem Cells Derived from Menstrual Blood Versus Bone Marrow in the Presence of Human Platelet Releasate

In recent decades, stem cell therapy has been introduced as a novel therapeutic approach for patients suffering from bone disorders. Recently, menstrual blood has been identified as an easily accessible and recycled stem cell source. However, the osteogenic differentiation capacity of menstrual blood-derived stem cells (MenSCs) compared with other adult stem cells remained unsolved. The aim of this study was to investigate the osteogenic differentiation capacity of MenSCs compared to bone marrow-derived mesenchymal stem cells (BMSCs) in the presence of human platelet releasate (HPR). Our results showed that MenSCs were strongly positive for mesenchymal and negative for hematopoietic stem cell markers in a similar manner to BMSCs. In contrary to BMSCs, MenSCs exhibited marked expression of OCT-4 and a significantly higher proliferative capacity. Mineralization, as judged by alizarin red staining, was more pronounced in differentiated BMSCs than in differentiated MenSCs in an osteogenic medium fortified with fetal bovine serum (FBS). However, FBS substitution with HPR in a differentiation medium resulted in typical impact on intensity of MenSC mineralization. The results of semiquantitative reverse transcription-polymerase chain reaction showed comparable levels of parathyroid hormone receptor and osteocalcin transcripts in both types of differentiated stem cells in an HPR medium supplemented with osteogenic inducers. However, the upregulation level of alkaline phosphatase was relatively lower in differentiated MenSCs than that in differentiated BMSCs. We concluded that despite lower osteogenic differentiation capacity of MenSCs compared to BMSCs, substitution of FBS with HPR could equalize the osteogenic differentiation of MenSCs. Therefore, by taking advantage of osteogenic driving potential of HPR, MenSCs could be introduced as an apt and safe alternative to BMSCs for bone tissue-engineering purposes.

Culture of transgenic Drosophila melanogaster Schneider 2 cells in serum‐free media based on TC100 basal medium

Requirements of eliminating animal proteins from cell culture have intensified in recent years, with the pressure of regulatory agencies related to biopharmaceuticals production. In this work, the substitution of fetal bovine serum by yeastolate and a soy hydrolysate (Hy Soy) for the culture of Drosophila melanogaster Schneider 2 cells transfected for the production of rabies virus G glycoprotein was evaluated. TC100 supplemented with glucose, glutamine, lipid emulsion and Pluronic F68 was employed as basal medium. Results show that yeastolate was more efficient on cell growth stimulation than Hy Soy. Cells adapted in medium formulation supplemented with 3 g/L yeastolate, 1% lipid emulsion, 10 g/L glucose, 3.5 g/L glutamine and 0.1% Pluronic F68 attained a maximum concentration of 10.7 x 10(6) cells/mL, with the expression of 9.4 ng/mL G glycoprotein.

Unmasking large and persistent reductions in proliferation rate of aging cells.

We have reported that nontransformed sublines of NIH 3T3 cells that are incubated under the growth constraint of confluence for 10 d or longer exhibit heritable reductions of growth rate upon serial subculture at low density, which simulate the effects of aging in vivo on cell growth. There is also a marked increase in the likelihood of neoplastic transformation. After switching to a new batch of calf serum (CS), we found the reduced growth rate was no longer produced within the previously established timeframe. However, substitution of fetal bovine serum (FBS) for CS during the period of recovery from confluence or the following tests of growth rate resulted in profound inhibition of growth in cells serially subcultured from confluent cultures. In some cases, fewer than one in a thousand cells from subcultures of confluent cultures formed colonies in FBS although they cloned at relatively high efficiency in CS. The reduced growth in FBS was retained in the postconfluent subcultures after many generations of multiplication at low density in CS. Generally, similar results with individual variations were obtained with three other batches of FBS. The numbers of cells per 3-d colony initiated from subcultures of confluent cultures were lower than those of control cultures that had never been confluent. Supplementation of FBS-containing medium with CS fully restored the growth of the postconfluent subcultures to the rate in CS medium, indicating that there is a deficiency of growth factor(s) in FBS rather than the presence of an inhibitor. The results show that prolonged incubation at confluence induces a populationwide heritable increase in requirement for growth factor(s) in short supply in FBS. Because clonal studies have shown that the reduction in growth rate is irreversible and varies in degree from clone to clone, we propose it arises from damage to DNA at any of many different genetic loci or from chromosome aberrations. Such genetic damage is also consistent with the increased tendency for neoplastic transformation in subcultures from the long-term confluent cultures.

Enzyme-linked immunosorbent assay for detection of specific antibodies to Ureaplasma urealyticum serotypes.

Optimal conditions of a micro-enzyme-linked immunosorbent assay system for the detection of immunoglobulin G antibodies to Ureaplasma urealyticum were established with rabbit antisera. Initially, the antisera, raised against eight U. urealyticum serotypes grown on medium containing horse serum, displayed nonspecific reactions with our enzyme-linked immunosorbent assay antigens. Substitution of fetal bovine serum in the medium eliminated this nonspecificity. The assay was then serotype-specific for the original eight U. urealyticum serotypes. The prominent homologous reaction was easily differentiated from the heterologous reactions. A one-way cross-reaction was observed with serotype 2 antiserum and serotype 5 antigen. The results were reproducible and could be obtained in 4 h with only 10 microliters of serum for eight serotypes. Optimal antigen concentrations for the U. urealyticum serotypes ranged from 0.40 to 1.60 micrograms/ml. Our results indicated that enzyme-linked immunosorbent assay has the potential for the detection of antibodies to specific serotypes of U. urealyticum.

Infectivity of Chlamydia trachomatis in tissue culture with newborn calf serum

By using representative strains of Chlamydia trachomatis serotypes, the efficacy of substituting fetal bovine serum with newborn calf serum for the isolation of this organism in tissue culture was examined. The criteria used were the quality and quantity of the iodine-stained cytoplasmic inclusions and the characteristics of the McCoy cells. Complete substitution of fetal bovine serum with newborn calf serum produced a detrimental change in the quality of the cytoplasmic inclusions and a dramatic decline in the inclusion count (P less than 0.001) with all of the chlamydial strains tested. There appeared to be no significant alteration in the characteristics of the McCoy cells. It is recommended from this preliminary investigation that newborn calf serum should not be used for the isolation of C. trachomatis in tissue culture.

Insulin binding in cultured Chinese hamster kidney epithelial cells: the effect of serum in the medium.

[125I] Insulin (porcine) binding to an epithelial cell line established from a Chinese hamster kidney, CHK-AC E-100, showed an optimum at pH 8.0 and reached a maximum after 2.5 h incubation at 25 degrees C. Dissociation of bound [125I] insulin was facilitated by the addition of unlabeled insulin in the dilution buffer. Porcine insulin effectively competed for [125I] insulin binding to the cultured cells and was 30 and 90 times as potent as guinea pig insulin and porcine proinsulin in causing 50% inhibition of [125I] insulin binding; glucagon was completely ineffective. Scatchard analysis of the binding data yielded a curvilinear plot and a capacity of 0.6 ng/10(6) cells; the average affinity of the empty receptor, Ke, was calculated to be 1.78 X 10(6) M-1 and that of the filled receptor, Kf, 0.57 X 10(8) m-1, Substitution of fetal bovine serum (FBS) in the culture medium with bovine calf, bovine newborn, of bovine calf serum altered insulin binding characteristics in the cells and reduced cell growth. Insulin binding characteristics of cells grown in hormone-supplemented medium containing 0 to 0.1% FBS were similar to those of cells grown in minimum essential medium (MEM) containing 2 to 5% FBS. The data indicated that the established Chinese hamster kidney epithelial cell line CHK-AC E-100 possessed specific insulin receptors and the characteristics of the receptors could be manipulated by changing the serum in culture medium.