I am looking at the feasibility of building a reprap to design a structural scaffold interlaced with a sugar lattice which would then be put into a biogel to culture cells, once these cells take hold, then dissolving out the sugar, exactly like they did at UPenn, and hooking it up to a vascular bioreactor that would feed the cells and mimic physiological forces.

[www.nature.com]

These guys used detergents to strip kidney tissue to a structural scaffold then reculture stem cells onto them. My thoughts are to evaluate if it is possible to build that initial scaffold from a 3D printer. Has anyone taken a look at building scaffolds, biogels, sugar lattices, or bioreactors, in concert with using a reprap?

-Soon to be american physician with a background in biomedical engineering that can't sit still for 5 minutes

Hey,
printing the scaffold with a 3D-Printer is an interesting idea. However, the stem cells will only rebuild the kidney if they have a reason to become kidney cells which is given by the biological scaffold but not by the scaffold from the 3D Printer. BUT... this is state of the art up to now. If a replacement would be found, for example a chemical compound that makes the stem cells differenciating to kidney cells you could include that into your scaffold. Also the use of hIPS cells could avoid the ethical problems with common hES cells.
I like the idea very much. Are you sure that it is a good idea to dissolve the sugar out after the cells took hold? Maybe keeping the scaffold would be a better idea?

You can 3D print a scaffold, use a scaffold material already generated or decellularize and actual organ as described in that study. What cells would you be culturing and what do you plan to differentiate them into? There are many factors to think of here, before selecting the scaffold itself. As Daniel mentions above, the signals you provide will decide the fate of these cells. Media components, nutrients, cytokines and growth factors, and of course the environment of the culture/ bioreactor all have influence on the fate and viability of the cells. Perhaps see this study for a method by which adipose derived stem cells ( adult) cells can be reprogrammed. Or these studies for tissue engineering methods.