The ability to grow organs for replacement in the lab would have been considered as part of science fiction just one or two decades ago. However, as our knowledge of organ development has been steadily increasing, and this has led to the emergence of a new field, called Regenerative Medicine.
Before going on to discuss a few aspects of the field, I wish to give you a short summary of what happens during development. All multicellular, sexually reproducing organisms start from one cell, which divides and divides and divides to produce more and more cells, and these cells, in the early stages of embryonic development are capable of forming many kinds of tissues, they are described as being undifferentiated and are known as stem cells.
The eventual differentiation of a cell, and the type of organ it forms, and the types of tissues it does this through are all determined by the external environment which can supply cues that regulate gene expression. Being aware of this can be used to turn stem cells growing in the lab to the desired kind of tissue, by means of conditioning the environment to supply the apposite cues.
I wish to introduce you to two videos at this point, both from EuroStemCell.
This one is called A Stem Cell Story and gives you an idea of what Stem Cells can do.
This one, about Cell Culture, introduces you to some of the laboratory work that goes into the culture of stem cells and some of the basic principles that can be used to turn stem cells into the desired tissue type.
Now the problem, you see, isn’t just the production of the requisite cell types, although it may not be difficult to envisage the limited use of the cell types you want to replace damaged sections of already extant organs. The real challenges in the field are in the production of organs in the laboratory.
Organ formation introduces the concept of spatial specification, the cells you have must be put into specific configurations such that they form organs…
There are two ways this can be done.
1) Using sheets of biodegradable polymer, print stem cells or organ precursor cells layer by layer and then stack all the layers together. Once the cells have fused you can melt the polymer, leaving the organ in place.
This can be done using, among other things, a modified inkjet printer that spits out cells.
This is an introduction to an organ printer.
This one enables you to see more of the technology.
2) Using cadaver organs.
Cells are stripped away using a detergent from cadaver organs, and the collagen framework that results is then used as the scaffold.
An example of that approach in action is this
In both cases the seeded scaffold has to be put in a bio-reactor where the necessary environmental factors to ensure differentiation into a particular organ are present.
You can find more videos about the field below.
How about a couple of textbooks?
Fundamentals of Tissue Engineering and Regenerative Medicine, Ulrich Meyer et al , Springer, ISBN: 978-3-540-77754-0
Tissue Engineering, van Blitterswijk et al, ISBN 9780123708694, 2008.
I hope you can start to see how science can change, improve and extend life, and if it interests you I think you may want to start looking at careers in this field.
That is all from me as far as this introduction goes, but I may deal with some areas of this field in-depth in future posts.
Happy Reading 🙂