We've got a new niche!

The SCN Blog has a new name and a new home: http://www.signalsblog.ca

After nearly four years and 207 blog posts, we finally outgrew our dish, so to speak. Late last year, we began planning with the newly-formed Centre for Commercialization of Regenerative Medicine, who indicated an interest to begin blogging in the sphere. (Perhaps you'll recall our name contest?) Why have two blogs competing when one can do the job? The result is Signals Blog (the new name came from an SCN staff member who sadly was not eligible for a prize), which will continue to bring the same level of insight, commentary and research news you've found on the SCN Blog, but will add new perspectives and news on biomaterials, regenerative medicine and commercialization.

We think it's a great partnership that will provide a more comprehensive view of the world of stem cells and regenerative medicine. 

To ease the transition for readers, all archived posts from the SCN Blog have been moved to their new home and RSS feeds will be updated to the new address. Comments will be closed on this site, but we'll keep a copy of the archives here for the short term. 

This is our final post on this site: please update your links and check out our new niche at www.signalsblog.ca!

View from the floor 5: Pushing the boundaries with technology

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To read this article, please visit Signals Blog: View from the floor 5: Pushing the boundaries with technology

Till & McCulloch Meetings 2012: Lessons to learn from leukemic stem cells

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To read this article, please visit Signals Blog: Till & McCulloch Meetings 2012: Lessons to learn from leukemic stem cells

Gene deletion to create insulin-producing cells

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To read this article, please visit Signals Blog: Gene deletion to create insulin-producing cells

Using titanium to induce bone differentiation and personalized implants

by Angela C.H. McDonald

Titanium can be found everywhere. It is used in cars, sporting equipment and even jewelry manufacturing. But did you know that titanium products are used inside the human body?

You may know someone who has undergone a joint replacement procedure or someone who has a dental implant. For decades, titanium alloys have been used as a biomaterial for these applications.

Titanium is a biocompatible material, which means that it is able to integrate into the body without being rejected. This is a major reason why titanium biomaterials are so popular in orthopedics and dentistry. However, the ability of a titanium implant to fuse with surrounding bone tissue inside the body (a property known as osseointegration) needs to be improved.

The evolution of biomaterials

by Roshan Yoganathan

I’ve been working in the field of biomaterials for over five years now. A short period of time, but nevertheless I’ve noticed that the field has evolved considerably. Since the inception of “biologically compatible materials,” their capabilities, functionalities and uses have undergone multiple stages of change.

There are distinct turning points when biomaterial research is thought to have evolved. I believe we are currently in the third generation and slowly shifting to the fourth (more on this later).

So here is how I see it, starting from the beginning.

Good start to the year for umbilical cord blood stem cells

by Angela C.H. McDonald

In 1988, the first umbilical cord hematopoietic stem cell transplant was conducted and since that time, over 20,000 umbilical cord blood transplants have been reported around the world. The technique offers several advantages over bone marrow in the treatment of blood disorders including noninvasive accessibility to umbilical cord blood as well as decreased graft versus host disease and superior immune recovery following transplantation. 

Despite these advantages, umbilical cord blood transplantation remains best suited to small children due to the low cell numbers available in a single umbilical cord blood unit that make it of limited use in adult patients. Transplantation of two cord blood units has improved the outcome of adult patients, but there are simply not enough cords available to make this a viable strategy in the long term. 

To overcome this hurdle, researchers have been looking for methods to culture cord blood in vitro with an aim to expand the numbers of stem cells found in a single cord unit and thus to circumvent the need to use two umbilical cord blood units for an adult patient.

It would seem we are getting close. Last month, a method for expanding human umbilical cord blood hematopoietic stem cells was published in Cell Stem Cell. Lead researcher Peter Zandstra and colleagues used computational and experimental approaches to design a strategy that yields an 11-fold increase of self-renewing, multi-lineage repopulating hematopoietic stem cells within 12 days of umbilical cord blood culture. 

In culture, hematopoietic stem cells rapidly produce mature blood cell types that subsequently produce secreted factors inhibiting hematopoietic stem cell expansion. The trick is to dilute accumulating inhibitory factors to allow expansion of the stem cell pool. The researchers computationally simulated hematopoietic stem cell population dynamics and culture strategies and identified a culture system to do just that.

Simulations predicted that an input stream of fresh media into the culture would lead to an increase in total volume over time and would be the most effective strategy for expanding the stem and progenitor cell pools. This prediction was tested experimentally and proved to increase stem and progenitor cell number by reducing the concentration of accumulating inhibitory factors as well as maintaining lower cell densities in culture, effectively slowing the rate and impact of inhibitory factor accumulation.

This culture system – known as a fed-batch culture system – provides multiple advantages over other inhibitory factor dilution methods of umbilical cord cell expansion, including lower costs due to a decreased requirement for culture media as well as a shorter culture time window. The researchers hope to move this technology into clinical trials in the near future.

While significant steps forward in the optimization of cord blood transplantation for the treatment of blood disorders are being made, a number of researchers are exploring alternative therapeutic uses for cord blood stem cells. Earlier this year, a Phase I clinical trial was approved to treat hearing impairment in small children with their own cord blood stem cells.

In a mouse model of hearing loss, studies have demonstrated that cord blood can restore inner ear organization and structure two months following transplantation. How do cord blood stem cells treat hearing loss? Researchers aren’t quite sure. Cord blood stem cells may regenerate lost hair cells in the cochlea, restoring function or they may home to the site of injury in the ear and induce the body’s repair mechanisms (click here to read more). Research is underway to uncover the mechanism of cord blood-mediated hearing restoration. While this research is preliminary, results from animal studies are intriguing and I know I will be waiting to hear about this study’s progress. 

 

A crack in the origin of eggs: policy and fertility implications of oogonial stem cells

by Lisa Willemse, with Ubaka Ogbogu and Timothy Caulfield

The announcement last week that a team of researchers had identified stem cells responsible for generating human eggs caused a ripple of excitement for several reasons. Not only does the news end a controversy regarding an assertion by the same research team that such oogonial stem cells even existed in humans (based on research done in mice), it would appear that this finding will rewrite medical textbooks and change a long-held belief that women are born with all the eggs they will ever have.

Indeed, if oogonial stem cells can give rise to full developed oocytes, it represents a significant crack in the entire notion of fertility and the possibility that adult women of any age could reproduce, as many have noted. If this is the case, IVF clinics could one day find their doors wide open, with fewer limitations on what and who could be a potential client for treatment. 

A seemingly obvious question, then, would be whether such procedures to create eggs for fertilization from oogonial stem cells, either for research or reproductive purposes, would be legal. As we have seen many times before, policy is rarely able to anticipate the directions of science, and thus there is no provision that explicitly deals with the use of stem cells to create oocytes.

In Canada, such activities fall under the Assisted Human Reproduction Act (AHRA). Ubaka Ogbogu, Assistant Professor in the Faculty of Law at the Universtiy of Alberta (and regular contributor to this blog) notes:

Under the AHRA the process of creating oocytes from oogonial stem cells is not banned, but likely regulated (Assisted Human Reproduction Canada license required), however, if the recent Supreme Court of Canada decision is implemented by the federal government, the activity might not even be regulated at all or fall to the provinces to regulate. This would apply for oocytes created for reproductive purposes, but not necessarily for research purposes -- using the oocytes for stem cell research would be likely banned depending on the method, which would follow the same rules as for using normal oocytes for stem cell research. 

A further question that complicates matters, is whether the eggs, when created using this method, can be considered reproductive material. Answers to that question may have to wait until science has taken the time to both replicate the initial study and assess the quality and exact nature of the resulting eggs. As with many new findings, it will be some time before any of it translates into clinical options.

 

Inside the Sauvageau lab

by Lisa Willemse

One of the advantages of working in an admin office of an organization that funds stem cell research is that you tend to hear about what's happening in labs all across the country. So when I heard that some interesting things were happening in the Guy Sauvageau lab, I decided to pay an overdue visit to Montreal to talk to Guy and do some filming in the lab. It was a miserable December day -- rain sheeting down sideways -- and, well, even if everything didn't go exactly as planned that day, the lab was warm and welcoming.

While the video footage is not yet ready for posting (stay tuned), I did write an article on the visit, which has been posted in an excellent blog -- "The Crux" -- run by Lynne Quarmby, a molecular biologist at Simon Fraser University in Vancouver (and a writer of insightful, thought-provoking blogs about research and the realities of being a basic researcher in Canada).

Read the complete blog profile of the Sauvageau lab.

 

News roundup: open access, new funding for personalized medicine and spinal cord injury update

by Lisa Willemse

Some updates and news items of note:

Call for boycott of subscriber-based journals gains momentum

The ongoing friction between proponents of open access and the academic publishers has jumped into the spotlight once again with calls from a number of academics, most notably from prominent British mathmetician Tim Gowers, who publicly announced his decision to stop submitting and reviewing for Elsevier. His objections are worth reading. Within days of his comments, a web site was created that allows other researchers to pledge their support for open access and against the practices of Elsevier and other academic publishers. At time of writing, there were over 2400 signatures. Of course, this is not the first time such calls for open access have surfaced from within the research community, the last big push resulted in the formation of the Public Library of Science in 2000. 

Nor are the sentiments limited to the mathematics field -- within stem cells, Jim Till has long been a proponent of open access and keeps a close eye on relevant news on his blog and Alexey Bersenev has several posts on the topic on his blog, Stem Cell Assays. His summary of the current events includes a good list of the reasons for open access as well as links to other sources for the interested reader.

Shift to personalized medicine finds federal support

Yesterday, the Canadian Minister of Health, Leona Aglukkaq, announced a new initiative worth upwards of $135 million ($67.5M from federal sources, to be matched by partner funds) with a focus on personalized medicine -- the use of genetics, biomarkers and environmental conditions to tailor disease treatments to individual patients. The announcement was essentially a call for applications and while specific projects are not yet known, they will have a strong genomics component and be readily translatable into a clinical setting. More reason for those working in translational research to be happy, and yet another sign that basic research is in trouble.  

A good chunk of the funds is coming from Genome Canada, with other support from the Canadian Institutes of Health Research and the Cancer Stem Cell Consortium. Specifically, the contribution from the Cancer Stem Cell Consortium will support the highest ranking cancer stem cell research project. All projects are expected to last four years.  

Update to spinal cord injury summary

Finally, a note that the entry on spinal cord injury within the Stem Cell Network's patient section has been updated and expanded. We are working to update all the entries in this section and to add new ones in the coming year.