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?