Tissue/Organ Engineering

[AziaCole]

Honestly speaking, I'm not sure if this post is in the right place. I'm actually asking help for a reporting of mine, not for a homework. So, if I'm ever in the wrong place, I'm terribly sorry. Feel free to move this thread elsewhere if that's the case. And please don't kill me, Mods.

 

My report is on, as you might have seen from the tittle, about Tissue or Organ Engineering. I've research quite a bit on the topic and have already understood the basics, or at least I think I do. Basically, you create a protein scaffolding (or get one from a dead organism) of the tissue/organ you want to create, seed the cell in this scaffolding until it forms the tissue/organ then implant it in the patient's body.

 

However, even thought I've scoured the net, I still have a few question left unanswered. Five of them actually.

 

The first one concerns the scaffolding that will hold the cells in place. Getting one from a dead organism is easy, however, I can see no article that explains how to make on from scratch. Though, I have to hazard a guess that that approach is way harder that just getting one from a cadaver. Which is maybe why there's no article for that.

 

My next question is about the growth of this bio-engineered organs. While I was reading news articles about Hannah Warren, the girl who was transplanted with a bio-engineered windpipe, I noticed a comment that her doctor made. Apparently, Dr. Macchiarini, plans on replacing her windpipe with a new one after four years (or, at least, he had planned to, poor child). Why though? Does the organ not grow inside the body, and would soon be to little for the patient, kinda like a fake arm, and must be replaced one day? Or does it have a shorter lifespan than the original one and will later die? Why was there a need to replace the windpipe?

 

While I was reading some more articles, all of them mentioned that it was actually hard to create an actual 3D organ. They were able to create a pulsating mass of tissue in a petri dish, but it's shape was nowhere near that of the heart's. However, despite that, there are already people being transplanted with bio-engineered bladders and bio-engineered windpipe. Since I hardly doubt that they'd place a mush of flesh in the place of a bladder or a windpipe, and also because I saw pictures of bio-engineered windpipes in the net, I can only conclude that that these transplanted organs are indeed in 3D form. That means that they actually have a way of creating three dimensional organs. Or is the heart really has that complicated of a structure compared to that of a bladder or a windpipe?

 

Another one that got me confuse is where the cells would come from? From what I can gather, it's mostly autologous cells. But what type of cells? Stem cells from the patient? Cells from the organ you're trying to make? Or would any cell in his body will do, the skin, for example?

 

My last question is not actually going to be included in the report. I'm actually asking it because of my own curiosity. Since it came from the patient's own body, it's immune system will not reject it, but there is, as always, huge risks that the organ might just fail. What are the possible causes for that? Would they have shorter life-spans, like clones? Or what?

 

Well, Isn't this a long post. *laughs nervously*

 

I sincerely thank anyone who'd read this post until the end. As for anyone who'd reply and clear up any of my confusion, you guys are awesome. This is a really cool and interesting topic. While I was researching on this, I can't help but think how amazing the future would be if this technique is perfected. Tissue/Organ Engineering is really, really, amazing.

 

 

 

AziaCole ^o^

[CharonY]

A lot of things to go through I will address some merely off the top of my head but would have read up for some more details myself. As a general preamble I would like to mention that the field of artificial organs is still developing and there are wildly different approaches and rates of success. Since I am no specialist I can only cover a tiny segment and mostly from a biological perspective.

 

1) Scaffolds have different requirements for different types of tissue or organs. However, one approach is to use (micro)fabrication method to get a scaffold with biocompatible plastics and let cells differentiate on them. Depending on the complexity it can be a fairly straighforward mould or it may require precision lithographic methods.

 

 

2) I do not know the precise way they created the trachea but I assume that they essentially coated a scaffold with stem cells from the child (I could be wrong though). For example you could take a donor trachea, strip it of living cells and then replace with other cells.Another approach was to create a plastic scaffold and seed it. The whole system would be like a biocompatible tube, but it would not grow with the rest of the body (complex signaling processes would be needed in while the cartilage is built and I do not think anyone has been able to replicate that, much less control it).

 

3) Trachea are very simple, essentially flexible tubes. A bladder is basically an inflatable balloon Most organs have to carry out complex functions that require muscle movement, complex liquid (blood) control, filtering processes etc in a highly coordinate matter. The issue is less the 3D , but the functional part.

 

4) AFAIK the basic idea is to use stem cells as seed. But again, this approach is still in its infancy

 

5) AFAIK no complex artificial organs have been successfully produced using the receptor's cells. Current artificial implants are usually prosthetic devices so we do not really know how a complex cell based artificial organ would perform over time.

 

While the development is ongoing and interesting, it is clearly not on the level that we can just create an organ in the lab just yet.

Edited March 7, 2014 by CharonY

[AziaCole]

I see. Thank you.

 

You've answered a lot of my questions. I think I'll be able to do my reporting in class. Thank you so much!