Printing New Cartilage

Ben -   Researchers at the Wake Forest Institute of Regenerative Medicine have devised a new way to print out replacement cartilage in 3 dimensions and they've demonstrated that it works in a real animal.  To find out more, we are joined by Dr. Anthony Atala, the director of the Wake Forest Institute.  Anthony, thank you ever so much for joining us.

Anthony -   Good to be with you.

Ben -   So, why do we need to be thinking about printing artificial cartilage?

Anthony -   Well, we've actually been working on creating cartilage for quite a number of years.  There's a major need for cartilage of course for patients who suffer from conditions such as knee problems or problems with their joints.  So, having an available source of cartilage would be a good thing for patients in the future.

Ben -   What do we do at the moment when we need to make artificial cartilage or when we need cartilage for a patient?  What are our options?

Anthony -   Well, there are not many options right now in terms actually putting cartilage in place.  Once a cartilage wears out, it's very hard to actually put anything in there that would do a good job.  So, surgery is done, but really, there's nothing better than real cartilage.  Of course for example, if you have an accident where you have a hip fracture, you're putting in metal pieces in place instead of putting real ,what we call, elastic cartilage in place.

Ben -   So what's been the basis of your work?  What have you been doing?

Anthony -   We basically have been focusing on creating tissues and organs using the patient's own cells.  The concept is actually quite simple.  We take a very small piece of tissue from the patient less than half the size of a postage stamp and we then are able to expand those cells outside the body, and we then can start creating new cartilage tissue that could be implanted into patients in the future.

Ben -   And this tissue that you're growing outside of the body, does it have all of the right properties?

Anthony -   Well, that is one of the things that we're working on, to make sure that they have the right properties.  That is where the bioprinting comes in because you can actually lay down cells exactly where they need to be in a predisposed manner where you can actually programme a printer to do so.

Ben -   Now, we've been hearing a lot about 3D printing recently.  It does seem to be the future, but 3D printing of living tissue seems quite remarkable.  Does it work in the same way, whereby you have a sort of inkjet head full of a cell culture and you just literally lay down the cells where you want them?

Anthony -   That's exactly right.  If you can picture your typical desktop inkjet printer, it really is utilising very similar technology.  But instead of using ink, we're using cells.  You have a printer that goes back and forth, and what we do is we modified printers so that they would print one layer at a time.  So, instead of having a sheet of paper coming through one at a time, imagine printing on the same sheet of paper over and over again and just building up over the same area, until you make the 3-dimensional tissue that you need.

Ben -   Do you need a scaffold on which these cells can grow or can you literally just print them into 3 dimensions and they'll hold their shape?

Anthony -   No, you do need a scaffold actually.  It's a good question and we use different materials as scaffolds.  We use gels that look like gelatine if you will, then they will hold the cells together in their shape, and these gels can then harden to different consistencies as needed, and then we can also use fibres to print.  And in fact, we have been able to use a combination of both gels and fibres for our printing technology.

Ben -   So, when you've done this, how well did the cells survive and how well did they actually work when you did the mechanical tests that imitate what a real bit of cartilage is likely to go through?

Anthony -   The cells survived nicely.  In fact, what we do is we actually are using the same technology that you are familiar with in an inkjet printer.  What happens is you have little air bubbles that gets formed inside the cartridge.  You have little air bubbles that get formed and the cells get incorporated within those bubbles, and then basically then released without heat affecting the cells.  So the cells come down through the inkjet printer through the print head without being damaged and then we're able to lay them down one layer at a time until they're able to form where they need to in terms of creating tissue with properties which are very similar to those in patients.

Ben -   And do we think that in the future, this is a likelihood that we'll be able to just scan a knee for example and say, "Well, we need this exact 3D structure of cartilage.  Let's print one out" and then surgically pop it in?

Anthony -   Yes, that's in fact the direction that we're headed.  We are actually building printers that have scanners in them.  So what you do is, if you have the injured area, you actually scan the area and with the same piece of machinery, we are able then to go back and lay down the cells where they're needed in their correct 3-dimensional structure.

Ben -   Fantastic!  Well, that does at least sound like surgery of the future.  Thank you very much, Anthony.  That's Dr. Anthony Atala from the Wake Forest Institute of Regenerative Medicine.