Intro

I work with stem cells in the lab, so I want to share the information on that topic at that blog. There are lots of interesting articles and study materials about stem cells on the web that's why I'm trying to gather them all here.
Showing posts with label review. Show all posts
Showing posts with label review. Show all posts

2/07/2013

3-D printers can produce gun parts, aircraft wings, food and a lot more, but this new 3-D printed product may be the craziest thing yet: human embryonic stem cells.

Rebecca Boyle - Popular Science

3-D printers can produce gun parts, aircraft wings, food and a lot more, but this new 3-D printed product may be the craziest thing yet: human embryonic stem cells. Using stem cells as the "ink" in a 3-D printer, researchers in Scotland hope to eventually build 3-D printed organs and tissues. A team at Heriot-Watt University used a specially designed valve-based technique to deposit whole, live cells onto a surface in a specific pattern.

This article originally appeared at Popular Science.

The cells were floating in a "bio-ink," to use the terminology of the researchers who developed this technique. They were able to squeeze out tiny droplets, containing five cells or fewer per droplet, in a variety of shapes and sizes. To produce clumps of cells, the team printed out cells first and then overlaid those with cell-free bio-ink, resulting in larger droplets or spheroids of cells. The cells would group together inside these spheroids. Spheroid size is key, because stem cells need certain conditions to work properly. This is why very precisely controlled 3-D printing could be so valuable for stem cell research.

After being squeezed out of a thin valve, the cells were still alive and viable, and able to transform into any other cell in the body, the researchers say. It's the first time anyone has printed human embyronic stem cells, said lead researcher Will Wenmiao Shu, a professor at Heriot-Watt. But ... why?

Eventually, they could be used to print out new tissues, or as filler inside existing organs, which would be regenerated. It could even serve to limit animal testing for new drug compounds, allowing them to be tested on actual human tissue, said Jason King, business development manager at Roslin Cellab, one of the research partners. "In the longer term, [it could] provide organs for transplant on demand, without the need for donation and without the problems of immune suppression and potential organ rejection," he said in a statement.

The team took stem cells from an embryonic kidney and from a well-studied embryonic cell line, and grew them in culture. They had to build a custom reservoir — let's call it an inkwell — to safely house the delicate cells, and then they added some large-diameter nozzles. A pressurized air supply pumps the cells from the inkwell into the valves, which contain pressurized nozzles on the end. The team could control the amount of cells dispensed by changing any of the factors, including the pneumatic pressure, nozzle diameter or length of time the nozzle stayed open.

At first the researchers printed droplets, but ultimately, they were so precise that they made cell spheroids in a variety of shapes and sizes, like the university logo above. One interesting wrinkle: The cells also formed spheroids in the inkwells. More work needs to be done to explain that.

The researchers also took several steps to make sure the cells survived the printing process. Examining the results of several experiments, they found 99 percent of the cells were still viable after running through the valve-based printer. "This confirms that this printing process did not appear to damage the cells or affect the viability of the vast majority of dispensed cells," they write in their paper, which is being published in the IOP regenerative medicine journal Biofabrication.

Stem cells are powerful because they can develop into any cell in the body. Embryonic stem cells, which are taken from human embryos in the earliest stages of development, can be developed into stem cell lines that can be grown indefinitely. This is kind of controversial, especially in the US. But medical researchers think they could be hugely promising for a whole host of human ailments — stem cells could differentiate into neurons, potentially replacing the ones lost in degenerative diseases like Alzheimer's; or they could differentiate into pancreatic cells, curing diabetes; and so on.

Using a 3-D printer to produce gun parts has been pretty controversial, especially during the ongoing post-Connecticut-shooting gun debate. But that may be nothing compared to this.

http://io9.com/5981832/a-3d-printer-that-generates-human-embryonic-stem-cells

9/02/2012

Another one stem cell fraud

Wired news... Stem cell research becomes a strange place... Here's some recent events:

Shane Mayack, a former post-doc in Harvard lab of Amy Wagers, a rising star in the stem cell field, has been sanctioned by the Office of Research Integrity for misconduct.
Mayack, who has defended her actions on this blog as honest error — albeit sloppiness — and has not admitted to wrongdoing, must undergo supervision if she receives any federal grant funding over the next three years, under the voluntary agreement.
Here’s the notice, which appeared in the Federal Register this week (and which theBoston Globe was first to report):

Based on the report of an investigation conducted by the Joslin Diabetes Center (Joslin) and additional analysis conducted by ORI in its oversight review, ORI found that Dr. Shane Mayack, former postdoctoral fellow, Department of Developmental and Stem Cell Biology, Joslin, engaged in research misconduct in research supported by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), grants T32 DK07260–29 and P30 DK036836 and the 2008 NIH Director’s New Innovator Award Program grant DP2 OD004345–01.
ORI found that Respondent engaged in research misconduct involving two (2) published papers:
• Mayack, S.R., Shadrach, J.L., Kim, F.S., & Wagers, A.J. ‘‘Systemic signals regulate ageing and rejuventation of blood stem cell niches.’’ Nature 463:495–500, 2010.
• Mayack, S.R., & Wagers, A.J. ‘‘Osteolineage niche cells initiate hemotopoietic stem cell mobilization.’’ Blood 112:519–531, 2008.
As a result of Joslin’s investigation, both Nature 463:495–500, 2010 (hereafter referred to as the ‘‘Nature paper’’) and Blood 112:519–531, 2008 (hereafter referred to as the ‘‘Blood paper’’) have been retracted by the corresponding author.
Specifically, ORI found that:
• Respondent falsely represented von Kossa-stained bone nodule images in two (2) published papers:
Figure 2B in the Blood paper was copied from an unrelated published experiment in Figure 3, J Orth Surg Res 1:7, 2006, and was used to falsely represent Respondent’s own experiment for bone nodules formed in cultured osteoblastic niche cells.
b. Figure S2c in the Nature paper was copied from an online image for an unrelated experiment (at http://skeletalbiology.uchc.edu/30_ResearchProgram/304_gap/3042_Lineage%20in%20Vitro/3042_01_aCellCult.htm#mCOB) and was used to falsely represent Respondent’s own experiment for bone nodules formed in osteoblastic niche cells from young and aged mice.
• Respondent falsely represented eight (8) flow cytometry contour plots as different experimental results by using identical plots but with different labels and different numerical percentages.
Specifically, the following contour plots in the Blood paper, the Nature paper, an earlier version of the Nature paper submitted to Science (hereafter referred to as the ‘‘Science manuscript’’), and a July 2008 PowerPoint presentation were identical but were labeled differently:
a. Panels 4 and 2 in Figure 6C, Blood paper, and panels 1 and 2, respectively, in supplementary Figure 3b, Nature paper
b. Panel 3 in Figure 6C, Blood paper, and panel 1 in Figure 2, July 2008 PowerPoint presentation
Panels 1 and 2, Figure 2b, Science manuscript, and panels 2 and 3, respectively, in Figure 2, July 2008 PowerPoint presentation
Panels 2, 3, and 4, supplemental Figure 4A, Blood paper, and panels 3, 1, and 2, respectively, in Figure 4B, Science manuscript
Both the Respondent and HHS want to conclude this matter without further expenditure of time or other resources and have entered into a Voluntary Settlement Agreement to resolve this matter. Respondent neither admits nor denies ORI’s finding of research misconduct. This settlement does not constitute an admission of liability on the part of the Respondent.
Nearly two years have passed since we first wrote about Mayack. At the time, Wagers’ group had just retracted a 2010 Nature paper — with a notable exception: Mayack refused to sign the notice, nor did she sign the notice for the retraction of the Blood paper, which appeared in late 2011.
As she wrote on this blog:

… the readers of Retraction Watch are no doubt aware that in October 2010, a paper that I co-authored was retracted fromNature and a notice of concern was posted regarding a second paper published in Blood.
So, what went wrong?
The answer to that question begins with the fact that errors, not fabrications, were made in assembling figures for these manuscripts. I am likely the one who made these errors.
Mayack reiterated that position in a comment, through her attorney, to us today:

I remain deeply sorry to the scientific community for mistakes made during the preparation of figures corresponding to some of the work I performed as a postdoc at Harvard Medical School. These were mistakes in representation and presentation of the data, as corroborated by ORI’s findings of ‘falsely presented’, and were not due to fabrication, falsification, or plagiarism of scientific results. I am deeply committed to moving forward and strive to contribute positively to the advancement of science, which has always been my utmost interest.
Wagers recently received tenure.

http://retractionwatch.wordpress.com/2012/08/29/ori-finds-harvard-stem-cell-lab-post-doc-mayack-manipulated-images/ 

5/29/2012

...antipsychotic drug, Thioridazine, has activity against cancer stem cells



Mick Bhatia’s lab has found that the antipsychotic drug, Thioridazine, has activity against cancer stem cells.

The work, published in Cell (read paper here), indicates that Thioridazine works not by killing cancer stem cells, but rather by encouraging the stem cells to differentiate.

Bhatia’s group used a novel screening approach (see graphical abstract from the paper above) to find molecules that specifically differentiate cancer stem cells. Interestingly they found Thioridazine, which intriguingly targets the dopamine receptor expressed on certain cancer stem cells. Bhatia can be seen in the interview below talking about the finding.

You might think then that Thioridazine would be safe because it only targets cells expressing dopamine receptor, however the drug reportedly has significant safety concerns due to causing fatal heart arrhythmias and regulators have largely phased it out in both Canada and the U.S..

Even so, it may be safe for cancer treatments since it could be used for a much shorter period of time, speculated Bhatia. However it is still early days in this story so there is much to learn about this new route to attacking cancer. Still, a very exciting and important development.

1/11/2012

MSCs in Clinical Research (best reviews, part-2)

ResearchBlogging.org Trounson, A., Thakar, R., Lomax, G., & Gibbons, D. (2011). Clinical trials for stem cell therapies BMC Medicine, 9 (1) DOI: 10.1186/1741-7015-9-52





























































































































ResearchBlogging.org



      Bernardo, M., Pagliara, D., & Locatelli, F. (2011). Mesenchymal stromal cell therapy: a revolution in Regenerative Medicine? Bone Marrow Transplantation DOI: 10.1038/bmt.2011.81



ResearchBlogging.org
Siniscalco, D., Giordano, A., & Galderisi, U. (2011). Novel insights in basic and applied stem cell therapy Journal of Cellular Physiology DOI: 10.1002/jcp.22945



1/09/2012

The Best Mesenchymal Stem Cell Reviews (part 1)

I'm involved in MSC-research and I love brilliant articles on that topic. The list of my favorite reviews about Mesenchymal Stem Cells is here now:


ResearchBlogging.org Klopp, A., Gupta, A., Spaeth, E., Andreeff, M., & Marini, F. (2011). Concise Review: Dissecting a Discrepancy in the Literature: Do Mesenchymal Stem Cells Support or Suppress Tumor Growth? STEM CELLS, 29 (1), 11-19 DOI: 10.1002/stem.559
KNEE SURGERY, SPORTS TRAUMATOLOGY, ARTHROSCOPY
Volume 17, Number 11, 1289-1297, DOI: 10.1007/s00167-009-0782-4

ResearchBlogging.org A Comprehensive Review on Mesenchymal Stem Cell Growth and Senescence Krzysztof Książek. Rejuvenation Research. April 2009, 12(2): 105-116. doi:10.1089/rej.2009.0830.




ResearchBlogging.orgKim, S., & de Vellis, J. (2009). Stem cell-based cell therapy in neurological diseases: A review Journal of Neuroscience Research, 87 (10), 2183-2200 DOI: 10.1002/jnr.22054




Stem Cells Trans MedDecember 2011sctm.2011-0024
Concise Review: Clinical Translation of Wound Healing Therapies Based on Mesenchymal Stem Cells
Wesley M. Jackson, Leon J. Nesti, and Rocky S. Tuan

Inflammation and mesenchymal stem cell aging Gunter Lepperdinger
Current Opinion in Immunology Volume 23, Issue 4, August 2011, Pages 518-524
doi:10.1016/j.coi.2011.05.007

    And the very best:

ResearchBlogging.org Karp, J., & Leng Teo, G. (2009). Mesenchymal Stem Cell Homing: The Devil Is in the Details Cell Stem Cell, 4 (3), 206-216 DOI: 10.1016/j.stem.2009.02.001





To be continued...
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