Scaffolds and Stem Cells

So lucky to get such great lectures on foundational topics in regenerative medicine in class this week! Part of the tour of foundational topics – with Dr. Aaron Goldstein on TE last week, Thomas Brickler and Ann Nichols on Basic Bio, and Dr. Karen DePauw on Interdisciplinarity the week before that -, this week took us deeper into information on the materials of regenerative science and engineering.

Dr. Abby Whittington, MSE, delivered a lecture on Scaffolds & Polymers, and Dr. Jennifer Barrett from the Leesburg VT Equine Medical Center shared an Introduction to Stem Cells with us. Both Dr. Whittington and Barrett are faculty participants in the RM IGEP.

For class participants —

From these lectures, is there a topic outside of your normal research that you found particularly interesting, and is there anything that you might have learned during this week that you think is worth noting or is just an interesting tidbit? (For me, I found the species differences in pluripotence that Dr. Eyestone chimed in with very interesting.)

Do you have any nagging questions that you didn’t get to ask in class or that occur to you in reflecting on the past two weeks that you’d like faculty participants to address in the coming week?

Dr. Will Eyestone will be leading us in discussion of cell-based therapies on Tuesday next week, followed by Dr. Michelle Theus sharing her research on brain and spinal cord injury applications on Thursday, so we can get into many of the applications of the materials we’ve heard about soon.

Please remember to email me to reserve the medical tourism topic that you wish to write up for Sept 29th and present on during class on Sept 29th and Oct 1st. — Ashley


  1. Personally, I found the iPS cells quite interesting as I don’t typically work with cells but on materials. I’m curious how the researcher was able to get cells to dedifferentiate into stem cells and if researchers since then have noted any differences between naturally occurring stem cells and these induced stem cells, either in experiments using these cells or in studying the cells themselves. Something to look into!

    We’re talking a lot about using regenerative medicine to repair damage in the body and a little about using it to cure diseases. A topic we haven’t addressed is using regenerative medicine to enhance and whether that would always have a negative connotation (similar to doping in athletes) or could it have a positive connotation in improving human health. Another way to look at it would be that our “normal” is actually damaged or diseased (and in fact our bodies are in flux constantly with threats occurring from abnormal cells or bacterial/viral/protozoa invaders). Prophylactic medications is probably the farthest this has gone legally, but extending or improving the human existence is something that we call try on an individual level in exercising, eating healthily, etc. What would that look like in regenerative medicine?

  2. I really liked the opportunity to think about scaffolds this week as my research mainly focuses on using stem cells for their growth factor or anti-inflammatory factor production. I guess for me, many of the material types that we talked about I have been exposed to in surgery. The whole time I couldn’t stop thinking of how I could combine the growth factor properties of my stem cells with certain sutures or mesh implants that we use in soft tissue surgery. For example, I was wondering how much better a mesh hernia repair in a horse would be if the mesh was impregnated with cells to provide both cellular material to start forming tissue across the gap, but also growth factors to stimulate healing. I am grateful for that lecture because it has encouraged me to look into this further and has given me background information so I can understand studies using scaffolds better.

    In Dr Barrett’s lecture we were talking about the difference between embryonic stem cells vs. mesenchymal stem cells vs. somatic cells in terms of their ability to continue to divide. In the mix we were also talking about tumor formation how stem cell markers may not be as static as what we think. Looking into CD markers further quite a few of them are to do with cytoskeletal organization, cell migration, cell-cell and cell-matrix interaction as well as control of the cell cycle (i.e. CD105, CD44, CD90). Given this, and the fact that I have observed alteration of CD markers in my own research, how worried should we be about stem cells we use for treatment becoming cancer-like? We are talking about cells that can continue to divide and could be able to change the very thing that we are using to define them based on the physical situation they are in. Does this concern the faculty too and what checks should the scientific community have so that we can detect potentially deleterious changes in our stem cells?

  3. I enjoyed learning about the different biomaterials out there that can be utilized in tissue engineering. In fact this is an area I am actively researching for applications in tendon regeneration. In my readings, I have come across many labs who have progressed from using homogeneous scaffold materials to design in vitro models, to composite bioscaffolds consisting of different molecular components, fibrillar structures, layers and porosity, among other material properties. It is interesting how different biomaterial properties can be combined to develop materials that are more biomimetic or structurally similar to their in vivo counterparts. Though the native extracellular matrix is the preferred choice in many labs for in vitro graft construction, synthetic alternatives have caught the fancy of many tissue engineers, because these are commercially available and easy to manipulate.
    I recently attended the TERMIS conference in Boston and some of the keynote speakers talked about real-world experiences, such as artificial organ transplantations. They talked about children and adults who are leading perfectly normal lives with artificial organs. It would be good to talk some more about real-world applications and bench to bedside technologies currently available out there. I think one of the best motivating aspects of regenerative medicine research is that so much of it is being translated to real life scenarios, in relatively short turnaround times.

  4. I found that tissue engineering is an interesting idea because it applies many engineering ideas, such as scaffolds and signals, while also using some agricultural languages, such as harvest. In this sense, tissue engineering is to cultivate tissues as well as to construct them. Following this line, I watched a TED talk about how scientific research may go to cell transplantation from organ transplantation, and available cells/organs can come from iPS cells which we also mentioned in class. Through iPS cells and their potentials to develop into organs, we can have more resources for those patients on organ transplantation waiting list. I think tissue engineering touches me not only because the language usages but also the intention to make organs out of something which is even invisible. This practice may re-shape the way we see and treat bodies from organs to cells. I haven’t had a very clear question about tissue engineering, but I think the future of tissue engineering has a potential to change our body conception.

  5. Dr. Whittington’s lecture on the development of scaffolds took me deeper into the tissue engineering side of regenerative medicine—an aspect of this field that is outside my usual research area. I found the specific techniques used in development of scaffolds particularly interesting. Although my research focuses on the biological/clinical side of regenerative medicine, engineering has always been an interest for me, and I was fascinated to hear about how techniques from engineering and biology work hand-in-hand in tissue engineering (I was especially interested by the description of using electrospinning to form nanofibers for scaffolds). I enjoyed the discussion of the challenges involved in engineering an entire organ with unique metabolic functions. Dr. Whittington introduced the questions of how closely an engineered organ should mirror the natural organ and how to maintain/develop the cellular microenvironment, and I am also curious about how an engineered organ would be maintained after transplant. Would the cells of the organ be able to communicate normally with the other cells of the body after transplant, or could cytokines or growth factors be administered to help with cell communication? Once the organ was established in the body, could the scaffold be degraded or would it need to be permanent? Does cell type, scaffold material, or organ type determine the answers to these questions, or is it a combination of all three? The last two weeks of class reminded me that every research answer opens up new questions, and I look forward to learning more about the growing research in this field in coming weeks.

  6. While I did ask this question in class, I would be interested in learning more about the variability of stem cell lines, and how researchers and the public view this uncertainty. There seems to be a disconnect between what the public understands about science (e.g. as very precise and exacting, with little to no margin of error when it comes to “good” science), and what is understood and comfortable in the lab.

    When I see that identical cells cultured in identical ways can differentiate differently with little understanding of why, I wonder how reliable therapies based on these techniques can be. And this is with intimate knowledge of the difficulty of controlling biological systems and a decent comfort level with the margins of error seen in science. The lay person who can see science as axiomatic in many ways, might understandably be nervous about such therapies. Certainly the long list of possible side-effects listed on medicine bottles and at the end of pharmaceutical commercials should prime us to expect a certain amount of variability and risk, when associated with the complicated politics of stem cells, I feel this could be extremely detrimental to the success of these therapies. This is not to say that we should hide the variability in order to promote the science, but rather that our ways of communicating science need to be more nuanced to better prepare people for the fact that “real” science comes with error bars.

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