Class blog for sharing and commenting on current events in biology.

Friday, April 5, 2013

Silas White                                                                                                                                      4/15/13                  
Bio-C Block Davies

Citation: University of Michigan. "Building better blood vessels could advance tissue engineering."ScienceDaily, 4 Apr. 2013. Web. 5 Apr. 2013.
One of the major obstacles of growing human tissue is the difficulty of keeping the blood vessels that nourish them alive.  Andrew Putnam is a researcher at the University of Michigan, and he and his colleagues seek to find the solution to this problem.  He and his team believe research into building better blood vessels could lead to curing disease that affects the circulatory system, such as diabetes.  The most common reasons lab grown blood vessels fail is that they are unstable and leak blood.  Putnam demonstrated how adult stem cells could fix this problem.  Traditionally, researches have used and developed drug compounds that would signal existing vessels to grow into new tributaries, but other researchers including Putnam and the University of Maryland team are using a cell based method.  “This technique involves injecting cells within a scaffolding carrier near the spot where you want new capillaries to materialize. In Putnam's approach, they deliver endothelial cells, which make up the vessel lining and supporting cells. Their scaffolding carrier is fibrin, a protein in the human body that helps blood clot,” as directly stated in the article.  According to Putnam, this new process is as easy as injecting the cells and then in a few days new capillaries have grown.  Of course, it isn’t that simple.  While it is easy to grow capillaries using this new cell based method, the vessels don’t always thrive.  Of order to remedy this, or at least collect helpful data, Putnam designed an experiment where he mixed four different blood vessel solutions that were each identical to each other, but one had cells from lung fibroblasts, one had adult stem cells from fat, and one had adult stem cells from bone marrow.  The fourth solution acted as a negative control, and therefore had no supporting cells at all.  They injected these solutions into mice, and found that the control and lung fibroblast groups produced leaky misshapen capillaries, and both groups containing different types of adult stem cells produced healthy capillaries, that didn’t leak blood.  Putnam envisions that in the near future, doctors will be able to take these support cells from the patients themselves and use it to inject them where the new blood vessels are needed.

Finding out how to effectively grow human tissue is a very important field of biology because it can lead to curing disease and being able to easily perform organ transplant.  For example, doctors could perform kidney transplants without needing a kidney donor because they could just grow the kidney themselves.  Being able to grow blood vessels only is a far cry from being able to grow a fully functional organ, but it does bring them one step closer.  According to Putnam, we may even be able to cure diabetes using this research, and that would be very exciting news!

       One critic for this article is that it was hard to comprehend at times because it used a lot of scientific terms that are hard to comprehend for someone without an advanced understanding of biology, but I also understand it may be hard if not impossible to explain something this complicated without using a lot of language specific to biology.  For the most part though, the article was easy to follow.   This article seems promising and hopefully Putnam’s research is expanded on soon.


  1. I liked how you initially adressed the problem and who was trying to solve it before you went in deeper. It was interesting how you explained how this problem was previously being treated and how it failed, and then you went on to explain Andrew Putnam's experiment and how it different from traditional methods. I also liked how after you stated the problem, you went on to talk about what was being done, the experiment, the results, and why it is important. I learned from this blog that something that sounds absurd, like growing a whole tissue, is actually possible and scientists like Andrew Putnam are getting surprisingly close to doing so.

  2. I thought this was a very well written response. I liked the way you summarized, getting the main points across to us without being confusing or going too far into detail. I liked that you also incorporated a quote, which stood as some back up to further prove points you were making in your summary. Over all, I think you did a good job with this project.