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6 posts from March 2012

March 27, 2012

The payoff of patenting your research: Aldagen as a case study

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March 21, 2012

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.

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March 19, 2012

Another success for StemCellTalks

by Ben Paylor

Photo: Mario Moscovici
For those who have been involved with StemCellTalks, it’s hard to believe that it’s already in its third year. Some degree of perspective on the pace at which it has been growing can be found in the numbers associated with the event. To date, StemCellTalks symposia have been hosted six times in four different Canadian cities involving nearly a thousand high school students, hundreds of grad students and a growing list of prominent researchers. With a further two symposia planned for 2012 (Ottawa and Vancouver) and students mobilizing in new cities to expand the initiative, it’s clear that StemCellTalks is here to stay.

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March 13, 2012

The evolution of biomaterials

by Roshan Yoganathan

Prosthetic_footI’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.

Continue reading "The evolution of biomaterials" »

March 06, 2012

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. 


March 05, 2012

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.