3D Bioprinting: can we create the hierarchical structures needed for tissue regeneration?

ACES Director Prof Gordon Wallace talks about on his upcoming 3D bioprinting presentation at the BioFest 2016 conference, 24-27 October to one of the event’s organisers, Elle Kress.

Q. Can you tell me a little bit about your presentation topic?

GW: I will be discussing new advances in 3D bioprinting that are helping us assemble structures that facilitate tissue regeneration.

Q: What most excites you about that topic?

GW: I think it’s the fact that with the advent of 3D bioprinting we’re able now to tap into a knowledge base that’s been accrued over the last three decades in the area of bio materials and other advanced materials that are relevant to tissue engineering.  We can now put that ability to create structures into the hands of researchers, and that’s really revolutionising how we think about what we can implement in a biomedical situation and how we can translate fundamental advances in materials into medical applications, in a very time effective manner.

Q: Does that mean it’s possible to print living cells?

GW: Yes, it is. Myself and others over the last few years have been developing specific inks, bio-inks, that mean that we can deliver living cells. There are various versions of this now. Our initial work was in inkjet printing where we could develop a bio-ink that protects the cells in the ink before printing and protects them during the printing process. This actually facilitates their survival and development after printing.

The advantage of inkjet printing was this ability to get unicellular resolution, putting one cell where you wanted it and another cell beside it, for example a nerve cell next to a muscle cell. For some applications and studies that’s important. For other applications a higher density of cells is critical, so we’ve developed extrusion printing inks that allow us to print a large number of cells, where you don’t need the unicellular resolution but you just want to distribute throughout a 3D structure. For example, we have been using that ability to print adipose stem cells for cartilage regeneration with our colleagues at St. Vincent’s Hospital.

Q: What do you see as the main challenges?

GW: The main challenge is identifying the best clinical areas to apply 3D bioprinting.  This is being overcome by the fact that the clinical community is embracing the idea of 3D bioprinting. If you were to talk to clinicians ten years ago about advances in biomaterials, without being able to translate those advances into real devices and structures, interest was lost very quickly. However now we are talking about the advances in biomaterials and the clinical community is starting to realise that it can be applied in specific areas. The challenge for us is to bring together those multidisciplinary teams driven by the clinical need for 3D bioprinting, then identify, prioritise and start to deliver real solutions to challenging medical issues.

Q: How do you think ACES will be able to solve those challenges?

GW: ACES has been at forefront of fundamental advances in material science for a number of decades. Over the last decade ACES has partnered with Australian National Fabrication Facility to create a fabrication facility with the ability to translate fundamental findings in structures and devices very quickly. It is really revolutionising how material science is implemented in biological systems and how clinicians can get access to that. But it’s not just about getting us closer to clinical application, as very important as that is. What we’re starting to realise is that our ability to fabricate actually enables us to perform fundamental experiments we couldn’t do before.  So how can we influence the development of stem cells, for example, to make sure they turn into neurons or into cartilage or into muscles depending on the application? That fundamental understanding is every bit as critical as we get closer to clinical applications.

Q: You spoke about how it has developed over the last ten years, and in more recent times. How do you see it developing over the next 12 months?

GW: We’re starting to realise that for each of these clinical challenges, or fundamental explorations that we would like to go on actually require a customised printing technology. So while 3D printing is available, most systems are limited in the materials that can be printed. We need to be thinking about how we develop in tandem with the materials in biology, customised printers and that’s what we’re doing. For each of the clinical applications we’re involved in, whether it’s for cartilage regeneration or for islet cell transplantation for example, we’re starting to realise that right from the start we need to build and create a customised printer specific to that particular task.

Q: In terms of developing the science, how do you foresee that benefiting a patient? How would the technology then go forward into assisting a patient in the long term?

GW: There’s a range of short term, medium and longer term applications that will be of direct benefit to those in need. The biggest application is in cartilage regeneration and we’re working with Professor Peter Chong from St. Vincent’s Hospital to develop an ink and customise the handheld bio-pen, which enables the surgeon to sculpt the 3D structure into the defect to customise a 3D structure for cartilage regeneration. We’re also starting to embark on sheep trials, having had very successful results on the bench and in preliminary animal trials to look at safety and procedures. We are also looking at islet cell transplantation to treat diabetes but the transplantation process is not very effective nor efficient. Along the journey we encounter other applications that we might never have thought of because of the advent of 3D printing. For example, I’m working with Professor Michael Coot, an ophthalmologist, to develop 3D printed glaucoma implants which are much more effective at monitoring and regulating the pressure in the eye for glaucoma patients.

Q: What have you previously discovered to advance this field?

GW: There have been discoveries across a broad spectrum of science and engineering, for example the types of materials that we know will be very effective in cellular interactions and cellular communications in order to initiate the right biological processes that we would like to engender. But also across with mechatronic engineers developing appropriate and new printing technologies, new ways to print materials, new ways to assemble in three dimensions. So they’re really important enabling discoveries. The critical thing is to align that with the clinical need, and to align that with fundamental experiments that enable us to understand the clinical need and come back with better interventions. So at the moment we’re developing ways that we can print layers of neurons on the bench. The idea is that we’ll start to replicate brain tissue to understand disease development on the bench. Diseases like schizophrenia and epilepsy, we will be able to test on the bench for possible interventions, whether that be pharmaceutical or other treatments.

Q: In your opinion, why should colleagues and students at the university attend the International BioFest 2016?

GW: I think it creates an environment and forum where you get that mix of skills and interests that’s absolutely essential to the development of fields, like 3D bioprinting. I think being immersed in that environment is important to understand how you communicate across traditional academic boundaries and to acquire those skills which are critical to being successful in an area like 3D bioprinting.

Q: Would you say this forum is particularly important for knowledge sharing across different universities and different research environments to talk about the sort of developments that are happening at the same time- albeit, different areas?

GW: Absolutely, the success in the field at a reasonable and effective period of time is absolutely dependant on getting the best minds in the country, if not the world, working as part of the team. It is crucial to understand what other people are doing and drawing on that knowledge. Attendees of the conference are facing big global challenges that require global expertise in order to deliver something that will be clinically relevant in as short a period of time as possible.