Cells Weekly – November 22, 2015

by Alexey Bersenev on November 23, 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. Safeguarding CRISPR-Cas9 gene drives
A group of researchers led by Harvard’s George Church described yet another safeguarding mechanism for confinement of unwanted gene drives, caused by CRISPR/Cas9 genome editing. Gene drives is a type of inheritance, where nearly 100% of progeny get desired genetic trait. CRISPR/Cas9 allows to engineer gene drives efficiently and potentially change wild species to serve a human need. The impact of gene drives and “undo mechanisms” was largely discussed this week. From Nature:

Although Bier says that the ability to undo a gene drive could be useful, he notes that its application may prove complicated. Neither gene drive will work in 100% of the population, meaning that the result will be a complex mix of different genome sequences. “I’m not saying it shouldn’t be done, but it would require some thoughtful modelling,” he says. And Esvelt notes that although the genetic changes may be undone, the effects on an ecosystem may not be fully reversible.
The safeguards, published today in Nature Biotechnology1, may calm some fears about the technology. One of the techniques provides a way of genetically separating the components that fuel a gene drive, so that the engineered mutation will not spread as rapidly through a population. Another is a molecular ‘undo’ button: sending a second gene drive out to undo the effects of the first.

Also read very interesting article on STAT – Gene drive gives scientists power to hijack evolution.

2. The legacy of Paolo Bianco
Prominent Italian stem cell researcher Paolo Bianco tragically passed away 2 weeks ago. I was following his research on mesenchymal stem cell with great interest for the last 10 or so years. But lately, he captured our attention as evidence-based science advocate. This week, EuroStemCell posted an eulogy, translated from Italian – The scientist who urged us to never surrender, written by Bianco’s colleague Elena Cattaneo.

3. Is commercialization of stem cell therapies lagging? Interview with Neil Littman
Neil Littman is a new Director of Business Development at California’s stem cell agency CIRM. He was recently interviewed by MendelsPOD. I found this interview very interesting. One of my favorite quotes about comparison of CART and stem cell-based therapies:

“The biotech market has been very hot the past couple years,” Neil says “But if you drill down into the details, there’s a real discrepancy between the funds that are flowing into therapies like gene therapy and CAR-T as opposed to funds that are flowing into stem cell based therapies.. . . The stem cells are really lagging.

He also said that it was CIRM’s mistake to invest into 90% of academic institution and only 10% of industry.

4. Making vocal cords in vitro
Researchers from University of Wisconsin for the first time created human vocal cord tissue in vitro:

We isolated primary human VF fibroblasts and epithelial cells and cocultured them under organotypic conditions. The resulting engineered mucosae showed morphologic features of native tissue, proteome-level evidence of mucosal morphogenesis and emerging extracellular matrix complexity, and rudimentary barrier function in vitro. When grafted into canine larynges ex vivo, the mucosae generated vibratory behavior and acoustic output that were indistinguishable from those of native VF tissue.

Also read coverage by Science News.

5. Update on Piero Anversa’s case
Retraction Watch provided an update on scandalous case of Harvard’s stem cell researcher Piero Anversa. He and his colleague sued their employer – Harvard’s Brigham & Women’s Hospital for biased investigation, which damaged their carriers. The case was dismissed this year. Anversa is moving to Switzerland.

6. CART cell therapy companies are racing to reduce manufacturing cost
Bloomberg posted very interesting article on competition in the hottest T-cell therapy field to reduce cost of cell product manufacturing. There are some speculative numbers in the article, but the message is clear – developers are working hard on it and it is a big race.

Adaptimmune has a goal of ultimately getting production costs down to $40,000 per patient while “conservatively” modeling a U.S. price of $150,000 per patient, CEO James Noble said. Kite is investing $30 million in building its new California facility, which will have initial capacity to treat up to 5,000 patients a year, Chief Financial Officer Cynthia Butitta said. It’s also looking to lower labor costs through automation, Belldegrun said.

Unlike Adaptimmune and Kite, which formulate their medicines from patients’ blood cells, Cellectis is developing an off-the-shelf treatment from donor cells. With that approach, its costs will eventually be in the range of $5,000 per patient for use in clinical testing, compared with about $15,000 now, Choulika said.

$5k for allo- CART cell product is totally disruptive, but I don’t think it’s possible as of today.

7. Fresh reviews:
A developmental framework for induced pluripotency (Development)
Human placenta in regenerative medicine (Front Bioeng Biotechnol)
Strategies to enhance the efficiency and kinetics of induced pluripotency (Cell Regen)
New Approaches to Biological Pacemakers (Trends Mol Med)

8.New methods and protocols:
Long-term maintenance of human iPS cells by automated cell culture system (Sci Rep)
Selective photosensitivity to remove residual pluripotent cells (Stem Cell Rep)
Adipose stem cell-derived conditioned media extends lifespan of mice with ALS model (Sci Rep)
Long-term cultures of human cornea limbal explants (PLoS ONE)
Generation of hippocampal neurons from ES cell-derived telencephalic tissue (Nat Commun)


Human Platelet Lysate (HPL) is widely used culture supplement for mesenchymal stromal cell (MSC) expansion. It was initially used in research labs since 1980s as growth factors-rich supplement for culture of variety of cell types. The first detailed study of HPL as alternative to Fetal Bovine Serum (FBS) for MSC culture was done by Christelle Doucet in 2005. In the last decade, HPL is increasingly used in MSC-based clinical trials.
What should be considered by developer when deciding on use of HPL? Here is my brief summary, based on recent review – Human platelet lysate: Replacing fetal bovine serum as a gold standard for human cell propagation?

In-housed made versus commercial
If you conducting small clinical study or preclinical work and located in close proximity to blood bank/ apheresis unit, you may consider to prep and test HPL in-house made HPL (auto- or allogeneic). There are many protocols you can choose from, depending on resources of your hospital.
If you’re planning to conduct large scale MSC trial with potential for commercialization, you can use allogeneic HPL products, available on the market. The industry recognizes its potential and offers variety of manufactured allogeneic HPL products on a market – Stemulate, MESEGEN, PLUS, PLTMax, Macopharma Platelet Lysate – to name a few. Are these reagents the same? No! You have to test them for your particular product and application.

Variability is HPL derivation and preparation
What is the difference between all HPL products? Well, there are a lot of differences. Let’s start from source material. The most frequent source material for HPL preparation is platelet concentrate, which could be derived from apheresis product or buffy coat or platelet-rich plasma. HPL also could be prepared from expired platelet units. Source material could be fresh, expired, irradiated and/or pathogen inactivated.
HPL preparation methods could vary significantly between manufacturers. The most frequent prep methods include: repeated freeze/thaw cycles, direct platelets activation by calcium chloride, sonification, solvent/ detergent treatment. Difference in anticoagulant as ancillary material may also have impact on final HPL product.
Yet another source of variability is pooling platelet concentrates/ units from multiple donors in manufacturing of large batches of allogeneic HPL. Manufacturers can pool as many as 50+ donors for manufacture of single HPL batch. Unlike pooled allo- HPL, autologous preparations are easier and safer. Limitations of auto- HPL preps could include comorbidities, age, restrictions for blood donation/ apheresis, absence of blood bank or specialized equipment.

Obviously, due to mentioned differences in preparation, all HPL products are different.

Safety of pooled HPL products
Since a lot of donors could be pooled for manufacturing of single batch, there is an increased risk of transmission of communicable infectious diseases. Regulatory jurisdiction, where commercial HPL are approved, plays a huge role in ensuring safety of these products. There are strict requirements for donor testing and increasing demand for pathogen inactivation in blood products. So, regulatory status of the product is very important here. You, as MSC product developer, must check and/ or request this information from manufacturers.

Culture-induced adverse effects
Cell culture-induced immunogenicity could be developed via absorption and internalization of antigens by MSC from allogeneic HPL. This possibility remains theoretical, since there are no reports on cell culture acquired immunogenicity, attributed to HPL. Impact of blood group type selection is still unclear and largely ignored by manufacturers of pooled HPL.
Yet another thing to know is genotoxicity – acquisition of chromosomal and genomic abberations in prolonged HPL-supplemented MSC culture. As of today, there are no reports on HPL-induced genomic abberations in MSC cultures.

Supply issues
According to some calculations, presented in review, supply of HPL is not as big issue as FBS:

Considering that an estimated 100 million whole blood donations are collected each year in the world [214], these figures suggest a potential for approximately 100,000e250,000 L of HPL per year from outdated platelet concentrates. Compared to the estimated volume of 500,000 L of FBS produced in 2003 [68,192], pHPL availability may be sufficient for human cell research and clinical applications.

Availability of many commercial HPL products allows to validate at least 2 suppliers for GMP manufacturing of MSC.

Lack of HPL standardization
Right now HPL production is experiencing standardization problem. Because in cell manufacturing process = product, lack of standardization may contribute to inability to transfer technology or compare results of clinical trials, performed by different groups.

However, there is a need to reach international consensus on production, quality, and safety criteria of both platelet concentrates and PRP used as raw materials and resulting HPL used as GMP- compliant supplements for ex vivo expansion of therapeutic cells for transplantation. As the use of HPL in cell therapy procedures is still emerging, it is quite conceivable that specialized human platelet derivatives will be developed in the near future both for specific therapeutic applications as for ex vivo cell expansion, thereby opening far greater potential applications than what FBS can provide.

Testing of HPL and comparison with FBS and serum-free media
The most important thing, of course, is to test HPL product for your product and application. What should be tested? Here is minimal “must” to do list:
– cell growth – proliferation/ PDL
– phenotype stability
– function check – potency (example: immunomodulatory properties)
– genotype (genomic) stability
Consider additional tests: impact of PHL on MSC differentiation, speed of senescence and potency after cryopreservation.
Ideally, you have to compare HPL product with FBS (or any other serum) and with serum-free media formulations. You better test at least 2 concentrations of HPL. There are a lot of HPL versus FBS comparison studies. For example, one of the recent studies, found lack of immunosuppressive properties MSC, cultured with HPL compare to FBS and commercial serum-free formulation.

Plelase feel free to share your experience with platelet lysate in comments! I’d especially like to hear about negative experience and HPL manufacturing hurdles and caveats.


Cells Weekly – November 15, 2015

by Alexey Bersenev on November 15, 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. Jeanne Loring named Stem Cell Person of the Year 2015
Prominent stem cell researcher from the Scripps Research Institute, Jeanne Loring won annual consent Stem Cell Person of the Year. I have to say I really like this choice! I’d like to point out just one, but very important thing that Jeanne did for the field this year – she stood up for patients in the clash against CIRM’s decision. She wrote to CIRM:

“CIRM has rather pulled the rug out from under the patient advocates. These meetings are supposed to be public, so how is the public going to participate if there is no access?…. I’m disappointed and the Parkinson’s patients are exceedingly disappointed. The Parkinson’s group is trying to find out the resolution, if any, of the timing of the grant applications.”

This kind of patient advocacy is very rare among academic stem cell researchers. Bravo Jeanne!

2. How to end stem cell tourism
Very interesting opinion article about the problem of stem cell tourism in US, was published last week. Two bioethics experts proposed to “re-evaluate current approaches” for clinical trials and regulation to find the way to end the stem cell tourism. They described historic examples from HIV/AIDS and breast cancer studies to highlight the role of patient advocacy groups.

Fixing the broken system requires more than education. Educational efforts to combat SC tourism for patients and clinicians should continue and be strengthened, but alone they are unlikely to be sufficient, largely because of the power of hope [9], [26], [27]. The development of adequate policies and regulations to connect, acknowledge and recognize the interests of the stakeholders—the patients, the researchers, the regulators, and the investors—is required.

Changes to current regulatory policy might include granting more people access to interventions earlier in the trial process, but preventing any access outside of rigorous studies. Alternatively, new regulation could allow studies to move from phase 0 or 1 to phase 2 earlier. Perhaps the FDA could even allowing marketing of therapies earlier…

Great article! Highly recommended!

3. New advance in wireless optogenetics
This year, optogenetics significantly advanced with introduction of wireless optogenetic systems. This week, one more wireless optogenetics method was described by researchers from University of Illinois:

These soft, thin devices are minimally invasive, and histological tests suggest they can be used in chronic studies. We demonstrate the power of this technology by modulating peripheral and spinal pain circuitry, providing evidence for the potential widespread use of these devices in research and future clinical applications of optogenetics outside the brain.

4. Evolution of cell and gene therapy technology
Biotech venture investor Bruce Booth wrote a great post on distinct features of cell/ gene therapy commercialization. He compares cell/ gene therapy clinical and commercial translation with conventional Pharma/ Biotech models.

More than a decade of “out-of-mainstream” academic research, and slow but methodical exploration by clinicians at a few medical centers, helped advanced the field to where it was 3-5 years ago – which is when the boom really began. The academics in this field kept it alive and advanced it when industrial R&D neglected it.
This outside-in evolution for CGT has had a few big implications on the biopharma ecosystem.

5. Layla case as a bridge to progress in clinical gene editing
You may heard exciting news about the first case of using TALENs-based editing of allogeneic CAR T-cells in patient. This week, Ricki Lewis wrote very interesting blog post – Will Layla Save Gene Editing?:

So why issue the news release about Layla so soon? It’s not as if there aren’t already treatments for leukemia. And a patient can’t just go and order her complex treatment at the local clinic.
The timing of the announcement may be important when we look back on the birth of gene and genome editing, just as we did 40 years ago for the recombinant DNA technology that has given us many useful drugs.
The news releases came out Thursday, November 5, as Layla and her family appeared on television throughout Britain. That was also the day that abstracts were published online for the American Society of Hematology annual meeting, to be held December 5-8 in Orlando. Cellectis’s stock rose, 11% after the news broke and another 3% the next day.
But between November 5 and December 5 will be another meeting, the International Summit on Human Gene Editing to be held in Washington, D.C. December 1-3. And that may be where Layla’s story has its greatest impact.

Very good read!

6. Genome editing gives a new hope for organ xenotransplantation
Nature posted a big piece this week on the future of organ xenotransplantation. A progress in the cloning of gene-modified pigs and genome editing could bring our attention back to organ xenotransplantation. The article mentions recent study on 62 genes editing in pigs by CRISPR-based techniques. It also describes attempts to commercialize xenotransplantation.

The gene-editing advances have brought new investment into the field. In 2011, United Therapeutics acquired Revivicor for about $8 million and announced an ambitious plan to start clinical trials of gene-edited pig lungs by the end of the decade. The company’s co-chief executive, Martine Rothblatt, secured land in North Carolina for a farm that could produce 1,000 pig organs per year and says she expects to break ground by 2017.

7. Acoustic levitation for generation of 3D neural constructs
Stanford’s Utkan Demirci group described the method for generation of brain-like 3D constructs, using bioacoustic levitation:

To address these critical challenges in brain bioengineering, we present here a unique, single step bio-acoustic levitational (BAL) assembly technology that is fast and facile to implement… Multilayers are formed in a fibrin 3D microenvironment by the effect of bulk acoustic radiation pressure on mammalian cells. Due to their larger density and lower compressibility than the surrounding fluid, cells are driven to the node planes of acoustic standing waves where there is minimal pressure.

8. The case of full face transplant
New York magazine posted a story of full face transplant. This is really fascinating read!

For the moment, the face belongs to no one. It floats in a bowl of icy, hemodynamic preserving solution, paused midway on its journey from one operating room to another, from a 26-year-old Brooklyn bike mechanic who’d been declared brain-dead 48 hours earlier to a 41-year-old Mississippi fireman whose face had burned off in a blaze 14 years ago.

9. New methods and protocols:
Simultaneous reprogramming and gene correction of patient fibroblasts (Stem Cell Reports)
Generation of an expandable mesoderm restricted progenitors from human pluripotent stem cells (eLife)
Rapid and robust generation of self-renewing human neural stem cells (Sci Rep)
Feeder-free generation of iPS cells from human T-cells using Sendai virus (JoVE)
Human mesenchymal stem cell-engineered hepatic cell sheets (Sci Rep)
Generation of clinical-grade human iPS cells in xeno-free conditions (Stem Cell Res Ther)
Identification of circulating cells with tissue homing and healing ability in mice (Sci Rep)
Generation of enterocyte-like cells from human iPS cells (Sci Rep)
Derivation of retinal ganglion cells using a CRISPR engineered ES cell line (Sci Rep)


Talks from recent conferences

by Alexey Bersenev on November 12, 2015 · 0 comments

in conferences

Many great presentations from three recent conferences were recorded and publicly shared. Here is summary of links.

1. Cells: from Robert Hooke to Cell Therapy
This event was organized by British the Royal Society and took place on October 5-6 in London. Cell Therapy Catapult recorded some talks:
Carl June (Upenn) on progress in CAR T-cell therapies
Sven Kili (GSK) on involvement of GSK in cell/ gene therapies
Bent Jakobsen (Adaptimmune) on cellular immunotherapy of cancer
Philippe Menasché (George Pompidou Hospital) – current state of cardiac cell therapy
Silviu Itescu (Mesoblast) on company’s progress in clinical trials
James Shapiro (Alberta Diabetes Institute) on a progress in human islet transplantation
Anders Lindahl (U of Gothenburg) – history of chondrocytes transplantation

All talks are delivered by pioneers and leaders in their fields! Don’t miss!

2. Stem Cell Meeting on the Mesa 2015
This is an annual event, which takes place in California every October. Co-organizer Alliance for Regenerative Medicine, recorder all industry-related talks and shared on their YouTube channel:
Featured Speakers & Panels (11 videos)
Company presentations (62 videos!)
Workshops (4 videos)

I’d highly recommend you to watch panels!

3. 2015 Gladstone Fall Symposium: From Stem Cells to Cures
Gladstone Institute in San Francisco is a magnet for the greatest stem cell scientists. Their Fall Symposium featured 2 speakers: Shinya Yamanaka and Blake Byers. Highly recommended to watch whole video!


Cells Weekly – November 8, 2015

by Alexey Bersenev November 9, 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. Scientists protest NIH moratorium on human-animal chimera research This week, scientists signed a letter to lift a ban on federal funding of research, involved human-animal chimeras. […]

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Remembering Howard Green

by Alexey Bersenev November 7, 2015 notes

“If that whole thing happen 10 or 20 years later it would be quite impossible, because you’re getting into bureaucratic mess so deep that you never able to get out…” Howard Green I captured this quote of Howard Green from Stem Cell Revolutions movie, because it resonates deeply today. He was talking about regulatory hurdles […]

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ASH 2015 abstracts pick

by Alexey Bersenev November 6, 2015 conferences

Public release of ASH’15 (American Society of Hematology) abstracts today was a bomb! Stocks of some gene/ cell therapy companies were heavily impacted today by release of ASH abstracts. Here is my pick of the most interesting clinical-focused presentations. Try to get more info and live tweet from ASH’15, which will take place a month […]

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Cells Weekly – November 1, 2015

by Alexey Bersenev November 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. Progress in whole human heart bioengineering This week, Harald Ott’s lab published the largest experimental study of bioengineering of decellularized human heart. The objective of this […]

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FDA explains homologous use of cell/ tissue products

by Alexey Bersenev October 28, 2015 regulation

FDA just released a new draft guidance document, which explains homologous use of therapeutic cell and tissue products (HCT/P) in details. The reason for such clarification was “many inquiries from manufacturers about whether their HCT/Ps meet the homologous use criterion”. I agree, determination of homologous/ non-homologous for some HCT/P applications could be confusing. Unfortunately, in […]

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Cells Weekly – October 25, 2015

by Alexey Bersenev October 26, 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. New turn in GDF11 controversy I’ve written about the controversy, surrounding rejuvenating factor – GDF11. In the origin of controversy is a claim, made by Harvard’s […]

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