We’ve seen numerous wonders emerging from Swansea University, a learning institution known for its research—much of which has revolved around bioprinting. The Wales campus is also home to 3Dynamic Systems, manufacturer of commercial 3D bioprinting systems such as the Alpha and Omega models, and also the Delta Carbon Fibre 3D printer.
Also known for their research studies, the 3Dynamic Systems team continues, despite a ‘transition period’ where they are focusing less on business and profit and more completely on finding treatments for those suffering from microtia—a condition where the ear is undeveloped, accompanied by diminished hearing. In their latest research, ‘Dual in situ crosslinking of polymer bioinks for 3D tissue biofabrication,’ the researchers outline their development of the following:
With these materials, they can create on-demand 3D biomaterials that have potential for use in reconstructive surgery. This work follows recent inspiration on the part of founder Dr. Daniel J. Thomas, demonstrated in a previous paper, ‘Could 3D Bioprinted tissues offer future hope for Microtia treatment?‘
“Following the publication of this short article, I started to get messages from parents whose children suffer from microtia and who were looking for new methods of treatment,” states Dr. Thomas. “After a month, we had received over a hundred messages, many of which were heart-breaking and sobering. Therefore, we decided to concentrate on developing this technology the best way that we could.
This meant that rather than focusing on developing bioprinting technology as a means of turning a quick profit, we decided to evolve and now focus on research that would do what is important, to develop treatments for those who need it.”
Thomas further explains their goals in helping to treat microtia as they plan to create innovative hydrogels and use the in-situ crosslinking technique for 3D constructs, along with ‘ensuring that initial 3D Bioprinted constructs can produce initial cartilage progenitor systems.’
In-situ crosslinking requires cells to be taken from living tissue, which is used to find the chondrocytes. According to the research team, they then fill one syringe with such cells and another with calcium chloride, which crosslinks the materials.
“Direct dual extrusion technology enables the deposition of combined hydrogel scaffolds and crosslinking agent. A typical layer resolution of between 150-250µm is possible when working with hybrid hydrogel based bioinks,” states 3Dynamic Systems. “The software system is used to control the bioprinter and instructs each of the high precision stepper motors to deposit the materials in layers. These layers act as an independent support to the 3D structure. This forms the shape of the ear structure, in which as the material is deposited then each layer is cross linked to form the required high resolution. This allows for the biofabrication of complex high resolution geometries.”
(a) Hematoxylin and eosin staining of immature cartilage tissue and auricular constructs showing condensation of cells present. (b) Immunolabeling collagen VI (shown in green) in the pericellular region of chondrocytes via nuclear staining (shown in blue).
After bioprinting, the ear structures are put into an ‘agitation incubator.’ Essentially, this keeps the tissue alive as it continues to mature.
“During a period of up to 21-days in an incubator then micro-environmental parameters are controlled. In order to produce biochemical stimuli, transforming growth factor-β1 has been added to the structure post Bioprinting in order to effectively produce cartilage and collagen matrix,” state the researchers.
The 3-D Bioprinting process used to generate using a printable bioactive ink (a) The toolpath of the 3D structure generated and (b) 3D-bioprinting process used to produce the ear structure, showing the difference between un-cross-linked and in-situ cross-linked.
(left) Bioprinted structure just after 3D in-situ crosslink bioprinting and (right) after three weeks of maturation.
Not only does the 3Dynamic Systems team see this as a progressive new way to offer reconstructive surgery for microtia, they are also looking forward to development of more innovative bioprinting.
“3D Bioprinting technology is potentially a very powerful application of automated tissue engineering. By understanding tissue maturation processes, this can also allow for novel tissue structures to be generated,” explains Thomas. “We are now going one stage further and are now focusing on a new process called laser 3D bioprinting. This new process will supersede traditional old school syringe-based bioprinting technology and will surely push bioprinting technology even further. It is our objective of one day developing our research, which could help others.”
The team is currently hoping to collaborate with other researchers around the globe in the development of 3D bioprinting technology. For more information, contact firstname.lastname@example.org. Discuss in the 3Dynamic Systems forum at 3DPB.com.
[Source: Research Information and Images sent to 3DPrint.com from 3Dynamic Systems]