• Cryopreservation of mesenchymal stromal cells can attenuate clinical immune effects
    As Jacques Galipeau reported in conferences and in the paper, cryopreservation could negatively affect therapeutic “immunomodulatory value” of mesenchymal stromal cells (MSC). There was no independent confirmation of Galipeau’s findings, and many MSC product developers remained skeptical. This week, Katarina Le Blanc published a report, which supports Galipeau’s conclusions and provides more insight into potential clinical value of this phenomenon. Let me just say – this paper could change the field! Le Blanc concluded that freeze-thawed human MSC compared to […]
  • Last year I was trying to capture and analyze results of all published clinical studies in cell-based regenerative medicine. One dimension that I was able to capture is using of media and serum for mesenchymal stromal cell (MSC) clinical culture. Today, I’d like to share some data.

    You can read about the methodology of this analysis here.
    Out of total 116 regenerative medicine clinical studies, 45 used MSC culture. I was able to capture information about media/serum use from 36 studies out of 45. I did not have access to 4 studies and the other 5 studies did not describe MSC culture method.

    Cell culture media
    Some studies did not specify cell culture media. DMEM (including DMEM/F12) was the most popular:


    25 studies of 36 used animal serum (FBS) and 11 studies used replacements of animal serum. 1 study did not specify any cell culture media supplements. 1 study was utilizing 2 animal serum replacements.


    Serum was only FBS. The most popular FBS concentration was 10%


    Finally, I looked at animal serum replacements. 1 study use animal replacement – bovine serum albumin (BSA), the other 10 used human products:


    How to cite:
    Bersenev Alexey. Use of media and serum in clinical culture of mesenchymal stromal cells. StemCellAssays blog. March 14, 2015. Available: http://stemcellassays.com/2015/03/use-media-serum-msc/


    Cells Weekly – March 1, 2015

    by Alexey Bersenev on March 1, 2015 · 0 comments

    in notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night!


    1. UK says YES to mitochondrial transfer techniques
    After long-term debate, UK’s House of Lords voted for approval regulation of mithochondrial transfer techniques to be used in clinic. This is a historic moment, because UK has become the only country, which took a risk to approve these highly controversial techniques. It could be a great human experiment and we will observe results of it soon. You can look at interesting discussion here.

    2. Results of regenerative medicine clinical studies from 2014
    I finally analyzed some results of my data capture attempt and post it today. I’d like to invite you to read and discuss it!

    - I was able to identify 116 clinical studies, which involve administration of cells as regenerative medicine.
    - Reports of cell-based regenerative medicine clinical studies results appear with a rate 1 every 3 days.

    3. RIP Dendreon 1992-2015
    February 23, Canadian company Valeant Pharmaceuticals acquired Dendreon assets via highest auction bid for $415 USD. The company sees good opportunities for Provenge sales. Nature posted a good piece about it. Provenge was the first immunocellular therapeutic (cancer vaccine), approved on the market. Dendreon made a history of cell therapy commercialization and definitely will get to textbooks. RIP Dendreon.

    4. Commercial “mesenchymal stem cell product” failed in post-marketing cohort analysis
    About 5 years ago Osiris Therapeutics sold allogeneic mesenchymal stem cell-based product “Osteocel” to NuVasive for orthopedic indications. This week, the Spine Journal published a report, which showed a failure of Osteocel in spinal fusion procedure:

    This is the first non-industry sponsored study to analyze a matched cohort assessing the one-year arthrodesis rates associated with a non-structural MSC allograft in one and two-level ACDF procedures. Although not statistically significant, patients treated with MSC allografts demonstrated lower fusion rates compared to a matched non-MSC cohort.

    5. Small molecule screening for stem cell enhancement
    Jeff Karp group from Harvard continues to search of new approaches to enhance mesenchymal stromal cells performance. New study, published in Cell Reports, describes a small moleculaes screening platform and new enhancer to boost of MSC homing:

    Pretreatment of MSCs with Ro-31-8425, an identified hit from this screen, increased MSC firm adhesion to an ICAM-1-coated substrate in vitro and enabled targeted delivery of systemically administered MSCs to inflamed sites in vivo in a CD11a- (and other ICAM-1-binding domains)-dependent manner. This resulted in a heightened anti-inflammatory response.

    Also read a post on The Stem Cellar.

    6. Retractions are more frequent in stem cell research
    Retraction Watch has an interesting post about rate of retractions in stem cell research. Turns out it is higher than in other fields. Researcher Ferric Fang did some calculations for Retraction Watch and concluded:

    I found 14,761,843 journal articles, with 209,038 containing the search term ‘stem cell*’. A total of 3,244 articles (0.022%) published since 1989 have been retracted, 110 of which contain the search term ‘stem cell*’. This represents 0.053% of all articles containing the search term ‘stem cell*’ that were published since 1989, which is a 2.4-fold excess over what would have been predicted if the stem cell field were representative of journal articles as a whole. In other words, an average rate of retraction would have predicted 46 retracted articles containing the search term ‘stem cell*’, but the actual observed number is 110.

    7. Immune system rejects tumorigenic iPS cell progeny
    A group of Japanese researchers demonstrated that human tumorigenic iPS cell-derived neural line could be safely rejected by immune system of immunocompetent mice. It happened after withdrawal of immunosuppression, which was used for engraftment of iPS cells:

    In this study, hiPSC-NS/PCs were xenografted into the spinal cords of immunosuppressed mice, resulting in the formation of tumors with the histological characteristics of low-grade gliomas rather than teratomas. The hiPSC-NS/PC-derived tumors were successfully rejected by discontinuation of immunosuppressant treatment. The issue of hiPSC-NS/PCs tumorigenicity remains a major concern in regenerative medicine applications; therefore, we propose that the discontinuation of immunosuppressants can provide a “safety lock” to ablate the grafted cells in the case of tumor development after stem cell transplantation therapy for SCI.

    Interesting study, but one may wonder if it could be extrapolated to human.

    8. New methods and protocols
    Genetic and epigenetic stability of human ESC depends on culture conditions (PLoS ONE)
    In vivo generation of a mature and functional artificial skeletal muscle (EMBO Mol Med)
    Co-culture of root ganglia neurons and adipose stem cell in regeneration model (JoVE)
    Safety assays for gene-modified cells (EMBO Mol Med)
    Generation of megakaryocytes from pluripotent stem cells (Stem Cells TM)
    Identification of keratinocyte progenitor in human adipose tissue (PLoS ONE)



    As part of CellTrials project, I analyzed some trends in adipose cell-based clinical trials. The methodology is described here. I’d like to show you a snapshot of some data from the last four years.

    Total number of databases listings
    From 2011 to 2014 there is a sharp increase in total number of adipose cell-based clinical trials worldwide. It jumped more than 3 times (from 11 in 2011 to 40 in 2014). The number of academic-based trials remained flat in the last 3 years. However, there was a big increase in industry-sponsored trials in 2014:


    It is important to recognize that significant part of so-called “industry” trials, listed in databases is not authorized (or sanctioned) by governmental regulatory agencies. These “trials” registered by clinics, which offer these cell therapies commercially. Therefore, the most correct term here is “listings” instead of “trials”. My rough estimation for 2014 is about 35-40% of listings are not authorized (not regulated). Because such clinics are commercial, it falls into “industry” category in my analysis.

    Adipose tissue-derived cell types
    The next slice of my data is analysis of cell types. I divided it for 2 categories: freshly isolated stromal vascular fraction (SVF) and expanded in culture – adipose stem cells (ASC). Here is a trend:


    As you can see, there is a equal interest to both cell types – SVF and ASC over the last 4 years.

    This post is a part of series Breaking Down Fat. In this series we will talk about identification, characterization and clinical processing of potentially therapeutic cell populations from adipose tissue. We started this series in response to the growing trend of wide (mostly uncontrolled) clinical use adipose-derived cells and some controversies/ misconceptions in the field.If you would like to contribute to this series or become a sponsor, please contact us!


    Cells Weekly – February 22, 2015

    by Alexey Bersenev on February 22, 2015 · 0 comments

    in notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night!


    1. Market authorization of stem cell product in Europe
    After long break (since 2013), we finally got a cell therapy drug marketing approval. Holoclar by Italian firm Chiesi Farmaceutici S.p.A. was recommended for approval by EMA at the end of last year. This week, Chiesi reported that “the European Commission has granted a conditional marketing authorization”. Holoclar is autologous stem cell-based cultured product for treatment of limbal stem-cell deficiency (mostly due to eye burns). Holoclar is manufactured by Holostem Advanced Therapies – a joint venture between University of Modena and Chiesi.

    2. Control of CRISPR-based gene editing by light
    Two studies, published in the last two weeks in Nature Chemical Biology and Chemistry & Biology, combined 2 breakthrough technologies – CRISPR/Cas9-based gene editing and optogenetics. The possibilities to play with these systems are blowing my minds, guys!

    3. Off-target-free precise gene delivery
    Another amazing method was recently described in Nature Communications. The authors find a way to modify AVV vectors to precise target particular cell population with antibody-like specificity:

    Displaying designed ankyrin repeat proteins (DARPins) on the viral capsid and carefully depleting DARPin-deficient particles, AAV vectors were made specific for ​Her2/​neu, ​EpCAM or ​CD4. A single intravenous administration of vector targeted to the tumour antigen ​Her2/​neu was sufficient to track 75% of all tumour sites and to extend survival longer than the cytostatic antibody Herceptin.

    4. Stem cells versus supernatant
    If paracrine effects from stem cells can have therapeutic value, why do we need to transplant cells at all? Few studies have demonstrated earlier, that supernatant, collected from mesenchymal stromal cell (MSC) culture could rescue tissue damage in animal models. However, very recent study argues against of using MSC supernatant alone in diabetes model:

    Present study exhibited that repeated-injection of MSCs reduced blood glucose and increased serum insulin levels in recipient rats. Injection of supernatant could not reverse hyperglycemia as efficient as MSCs. Interestingly; co-administration of MSCs with supernatant could reverse hyperglycemia more than either group alone.

    5. Higher versus lower passage of MSCs
    Some observations from clinical trials were made about greater therapeutic benefit of lower passages of mesenchymal stromal cells. However, new study published this week, argues that it may not always be a case, at least in some animal models. The authors compared MSC, cultured for 3-8 passages versus 40-50 passages in Huntington’s disease model:

    Contrary to what was observed in our previous study using rat BM MSCs, it is apparent that, in this model, mouse BM MSCs are more therapeutically beneficial after extended periods in culture.

    Very interesting results!

    6. New methods and protocols
    In vitro enrichment of ovarian cancer stem cells (JoVE)
    Human iPS cell-derived neural cells for modeling of chemotherapeutic neurotoxicity (PLoS ONE)
    Human iPS-MSCs differentiation into fibroblasts on artificial niche (Sci Reports)
    Isolation and expansion of mouse and human prostate progenitor cells (Stem Cell Reports)
    Testing serum-free conditions for propagation of fetal placental MSCs (PLoS ONE)



    More insight into steady state hematopoiesis

    by Alexey Bersenev February 21, 2015 hematopoietic

    Lat year, I’ve written about new methodology for tracking steady unperturbed hematopoiesis in situ. Recently, one more method, involved genetic labeling, was describe by group of German authors. New methodologies for studying steady normal hematopoiesis will allow us to make an important step from highly artificial bone marrow transplantation to more natural and precise models. Even though transplantation models is still a “gold standard” for assessment of hematopoeitic stem cell (HSC) function, everybody in the field would acknowledge of its […]

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    Clinical cell processing news – part 1, 2015

    by Alexey Bersenev February 17, 2015 cell culture

    Clinical Cell Processing News is a series about new protocols, products and techniques for clinical-grade cell processing and manufacturing. Cell processing devices, cultureware, bioreactors, GMP-grade reagents, cell separation techniques. This series is posted every 2 months. FEATURED: GMP-compliant protocol for rapid generation of antiviral T-cells (J Transl Med) FREE The generation of antiviral CD4+ and CD8+ T cells by CliniMACS CCS can be extended to a broad spectrum of common pathogen-derived peptide pools in single or multiple applications to facilitate […]

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    Cells Weekly – February 15, 2015

    by Alexey Bersenev February 15, 2015 notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night! 1. Cell therapy clinical trials – 2014 update I posted my cell therapy annual reports – analysis of databases listings in 2014 and trends 2011-2014: Total number of cell therapy trials, registered in international databases, continue to grow from year to year. From 2011 to 2014 a total number of trials increase […]

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    Lecture: George Church – Future of Human Genomics and Synthetic Biology

    by Alexey Bersenev February 12, 2015 lectures

    George Church is a remarkable figure of the modern molecular biology. He attracts a lot of attention by provocative claims and by his research findings. Interests of his lab spread from defining what is life to creating “genome-modifying drugs” for medicine. His main focus, however, is synthetic biology and genome engineering. His recent study on creation of “synthetic genetic firewall” for gene-modified organisms made a big buzz in the media. Many companies are hunting for him to offer “advisory board” […]

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    Breaking down fat: Non-enzymatic “minimal” methods for SVF isolation

    by Alexey Bersenev February 4, 2015 adipose

    In the previous post of the series I asked if stromal vascular fraction (SVF) of adipose tissue could be isolated by simple centrifugation? The answer to this question could be a “game changer”, because non-enzymatic methods for SVF isolation is the only possible hypothetical way to avoid FDA regulation as a drug. According to FDA, use of centrifugation fits in “sizing” definition and, therefore, autologous SVF could be exempted as “the same surgical procedure” even if tissue is more than […]

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    Cells Weekly – February 1, 2015

    by Alexey Bersenev February 1, 2015 notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night! 1. Cancer reprograms metabolism via metastatic niche Very interesting findings were published this week in Nature Cell Biology. Researchers used breast cancer model to demonstrate that glucose metabolism can be reprogrammed by cancer-released micro RNAs on premetastatic niche level: These results demonstrate that, by modifying ​glucose utilization by recipient premetastatic niche cells, […]

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