This is just some extra news that is worth showing the readers that the idea of taking a small piece of tissue from a patient, and then growing the cell into tissue in a lab culture in small microbiology petri dish, is very straight forward. This is something i already has been done at least once before by some other teams. Not only does the full tissue become synthesized in a culture dish, that tissue is reimplanted back into the cartilage defect areas of the patient. The entire process from the earliest step to the final step has been taken.
The last step now is to get the explanted tissue of chondrocytes to be grown into a columnar structure (via Thyroxine, refer to insanely critical study on power of Thyroxine to form growth plate organization ie columnar fashion back in 1994 by Dr. Ballock and Reddi Here) and have the released waste of proteoglycan and GAG (Glycoaminoglycan) into the ECM (Extracellular Matrix) to expand so that the tissue can expand, turning it into a “synthetic growth plate”. <– This step should not be that hard, and I believe it has already been accomplished in a research grant from 2012-2014.
Refer to the article “Doctors Have Discovered A Revolutionary Treatment For Knee Injuries” on Business Insider.
At Ohio State University, in the Wexner Medical Center, a Dr. David C Flanigan (His website is at www.flaniganmd.com) and his research team have been testing human cartilage grown in the lab. A patient named Taylor Landgraf, who was locally trying to get to the local gym and using a skateboard fell and tore the cartilage in his knee, as well as tearing his meniscus.
Taylor decided to look into getting some type of more modern type of treatment to repair his cartilage, since cartilage is probably one of the only tissue types which do not regenerate and heal itself, due to its unique structure. I would assume that he would get in contact with the Wexner Medical Center and somehow learn about the possibility of having lab grown tissue transplanted into his body.
So the researchers take a little bit of chondrocyte tissue as a type of tissue seed material from Taylor’s body. It is placed in a medium (agragose/hyaluronic acid/etc.) and grown in a cell line. The cartilage cells are replicated over and over again (I do have some issues here since it is well known that all cells have a limit to how many times they can replicated, similar to the idea of the Hayflick Limit).
Based on my own personal experience of listening to the speaker/CEO of RoosterBio, a company that sells mesenchymal stem cells, it was told to me that to have enough quantities of cells to form a reasonably large sized tissue, say even 2 cm by 2 cm, you would need around 60-200 Million cells. This suggests that if we assume cell mitosis, then to divide 10 times reveals a 2^10, or approximately 1000X magnification of cell numbers. What I am trying to say is that the amount of tissue you have to carve out of the patient may be quite sizable to have at least around 100,000 cells to start with (10^6). Assuming the Hayflick Limit of around 30 mitotic divisions (from the age of 20-30) , then we can start with much less. If we are assuming from the fetal stage, Wikipedia says instead that the limit of division is around 40-60 times.
Anyway, the result from starting with a cell line, and replicating it over and over again is a piece of living cartilage, about the size of a quarter (diameter of an inch, or 2.5 cm). You take that quarter sized cartilage, and carve it into the shape of the cartilage defect in the patient’s knee (or any other joint or location where cartilage has been scratched off). and pop it into the area where cartilage is missing.
So why is this worth mentioning? Is this big news or old news?
I wrote this post as a proof of concept. The type of cartilage that you get is most likely not going to be of the epiphyseal type, hyaline in nature. It will be fibrocartilage. The cartilage has an unorganized cartilage organization structure (ie. non-lamellar). Articular cartilage is hyaline in nature. Would the two different types of cartilage which now are next to each other bind at the boundaries and have something that will function overall at a reasonably good level? The reseatchers at this lab at OSU seem to think that this type of therapy is good enough for Taylor, at least semi-permanently for maybe 10-20 years. When that fibro-articular cartilage composite type starts to break down in 15 years, the researchers will have gone further on the tissue regenerative science and have something much better for him down the line in the future.
In fact, there is probably a much better technique for this Taylor patient which he should have tried, called Microfracture Surgery. Microfracture Surgery involves the surgeon just stabbing the subchondral bone layer underneath the now grinded out articular layer of the knee epiphysis to make a hole. The stem cell type medium that exists in the cavity of the bones will leak out, and form as a type of blood clot turning into fibrocartilage tissue.
This way of doing it by the team with Flanigan seems a little too invasive, and not that necessary. However, it shows that researchers can grown cartilage in the lab from a patients own chondrocyte (or maybe even MSCs) and grown the cells into tissue, and reimplanted back into the body, and have that transplant to work just fine.
This is another step in the long process for what we ultimately want. It is a proof of concept for one of the most critical ideas and steps.