Decellularization and tissue engineering

I've really been thinking about larger projects that are theoretically within our capabilities, and one that I feel isn't too far out is making organs using adult stem cells and decellularized matrix or some equivalent.

The first step is relatively easy. We can harvest some organ or tissue from an animal source and chemically strip off cells leaving an extracellular Material. There are tons of studies showing methods to do this. A rather easy method uses Triton X-100 and Sodium deoxycholate. Haven't tried sourcing it but if difficult, there are alternatives as simple as trypsin and EDTA. There are a couple of other steps needed like using nucleases to remove residual nucleic materials.. but it's cut and dry procedural stuff with easy to procure materials.

Alternatively, we could simply purchase some ECM product. Cormatrix makes a literal bag that implants are placed in that turn into vascularized tissue once placed. Sourcing might prove far more difficult, but I've been shocked as shit at the stuff that can be purchased on alibaba. It's a possibility. And of course there is the popular 3d printing stuff which makes a viable matrix... but the problem is that it doesn't have a lot of the local factors that specify to stem cells what to differentiate into. 

Ex.Cormatrix Extracellular Envelope

Next is the harvesting and growth of Adult Stem cells. Basically, what you're trying to do is to grow some organ using your own cells so that it can be implanted without being rejected or requiring anti-rejection medication. Some stem cells are invasive to get. For example, adult neural stem cells are a no go unless someone wants a hole in the head. (No, I won't do this for you.) There are a number of types that can be harvested... some you get from like dental pulp... others from bone marrow. One that's very promising can be harvested from the Olfactory mucosa. Easy to get and nearly non-invasive. 

There are a few gaps in my knowledge here regarding isolating the cells etc. but we'd basically need to make a really really bad ass bioreactor... or purchase one. In terms of running the reactor... it can be as simple as a maintenance bath or very very complex including the timed addition of pertinent growth factors and hormones. It just depends on how complex and how large the intended organ is. Differentiation of the stems cell is most often cued by the ECM... the local factors left over seem to be enough, but this is an area where we'd need to do some serious journal digging. It's not necessarily difficult, but I need a bit more knowledge. 

Of course, the next step is implantation. This is another one of the it can be easy or very difficult types of steps. If it's a sheet of tissue, it's pie. If it's a serious 3d organ structure we might need to perform microsurgery to attach the vessels appropriately. I'm working on  microsugery setup in my lab so I can probably take care of these aspects. 

Now, the big question is.... what type of structure is worth this effort? 


  • The bioreactor thing has come up before. I understand the industry is doing the whole "Everything costs a lot because everything buying it is rich", but what do hackerspaces (the biohacking kind) do for this? I presume bioreactor is fairly essential tech? Do they just fork out and pay a lot, or are there opensource ones already made?
    I mainly ask because it's the kind of area I could help with, as opposed to, you know, real biology.
  • It's not the effort, it's the equipment that holds us back. I've had plans to do this for a while but the big issue is that all the stuff you need, the bio reactor, cell lines, etc are all prohibitively expensive.
  • Well ive got the flow hood setup. Pics and a rundown are on their way. Im arranging liquid nitrogen. Havent started on the reactor but i dont feel its going to be too difficult. I think we can do this affordably. In terms of cell lines im really thinking autologous nonimmortaized stuff anyways. And if we make the right friends cell lines are much harder to share than a plant cutting.
  • You pretty much nailed it with the making an ecm. It is really that simple. As for the local factors for differentiation, my experience has been that people add those in themselves, be they chemical or mechanical or a combination of the two. This allows for more control in the differentiation. Of course, we were using a hydrogel as a matrix then, so there where no local factors. I believe this is the method a lot of people are looking into now, due to the high control that you get. 

    Liver has seemed to be the go to with all the organ printing companies out there. Tiny livers. I'm not sure what the implications of implanting a tiny liver would be, but it could be interesting.

    Hadn't we also discussed doing this in reverse? Basically, instead of building it up from scratch, taking and organ and stripping out the factors that cause rejection and then using it as an implant that way?
  • Yes but its not looking feasible without antirejection drugs. Autologous is far simpler.
  • edited June 2015
    for organ transplant it may be easier to build a system that could really remove the rejection factors but I think since we're biohackers and we don't just wanna replicate we want to improve it would be more interesting to try and grow one. That said the question does come down to what you're gonna grow. Also a liver is a good start. Really anything is. As to the bioreactor it's not technically difficult to make but it takes money to do it and expertise in a few fields, since this isn't your regular run of the mill bioreactor. Organs and such take more fine control to keep happy no? 

    So you'd probably want a few different feeds. The tank would need to be on the larger side unless you plan on growing an eye or a single vein or something.
    May want a main nutrient line in then a seperate line in that you can use to add in whatever you're using to guide the whole process. Then the usual gas lines and waste removal. Assuming you are gonna wanna automate it so that needs to be dealt with too. 

    As to cell lines ya you may need to make the right friends for that one. Or you could try growing yourself an organ of your own tissue. You have the liquid nitrogen setup and probably could invest in what's needed to isolate them. Could be cheaper than trying to hunt down a cell line. 

    but first thigns first, if you're gonna try this ya gotta pick what you're gonna make. So will it be organ or finger or testicle or what? If it's down to a vote I throw mine in for a eye or colon.
  • Yeah. .. something like an eye would be difficult as shit. That's not just tissue s.. that's like hox gene sequence shit. Im actually thinking of something like a small cluster of neurons. Perhaps using a murine brain as scaffolding. What would happen when I get the synapse s to for with my peripheral ns? No clue, but it should be interesting and it ties into some ideas I have re computer interface.
  • I have no clue about the technical aspect. But how about skin or cartilage/gristle? (not sure which is the correct term, the stuff that holds your ears in shape).
  • cluster of neurons is no organ though. Skin is derp easy, or at least it's been done quiet often. If you're going neural grow a rat brain. No need to use human tissue. If you're going no neural go rat liver or kidney or something. Then you can get 2 rats. if you're making a liver, use rat 1 to extract liver stem cells, use the other to get it's lier and strip it of everything other than connective tissue and then let the stem cells rebuild the liver. Then you can scale up and use human cells and a pig liver or something similar for the scaffold. 
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  • been thinking about tiny cultured muscles to generate power for implants. say they squeeze a piezo generator or something. and some types of tissue might have a measurable response to glucose or other chemicals, which would make for a good continuous sensor.
  • @SixEcho That'd be one awesome thing. As simple as putting it in parallel to a rectangular sheet of piezo material which is then slightly bend by the muscle. I don't expect 1.21GW output power, but enough to power a small implant.
  • There was a science mag online seminar that aired about a week ago about sourcing cell lines and the like.
    Yeah, you have to register, but it was pretty informative.

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