In recent years, 3D printers have become a universal technology; their increasingly low cost and technical advancement has opened many doors and enabled us to print a myriad of everyday life objects.
The medical field is no exception. Prosthetic limbs are perhaps the most obvious application, but 3D printing can achieve a lot more than this: synthetic skin, drugs and tissue engineering are prime examples. But what if 3D printing could also help with diabetes?
In people with Type 1 diabetes, the insulin producing cells in the pancreas (called islets of Langerhans) are destroyed through an autoimmune response. For some patients there are alternatives to permanent insulin injections. These include a pancreas transplant or islet (cell cluster) transplantation – where only the insulin-producing cells are transplanted into the liver. Islet transplantation is less invasive, although the rapid failure of a large proportion of implanted cells can limit its efficiency. It also worth noting that both of these procedures come with life-long immunosuppressant treatment.
A team of researchers in the Netherlands have investigated the use of 3D printing (referred to, in this context, as bioplotting) to provide a delivery media for pancreatic cells, and it looks promising. What the team did was to embed islets in 3D-printed, porous scaffolds, which protected and held the cells in place, preventing them from moving around the body.
Finding the right building material for the scaffold was critical. The team found that a hydrogel, made of a blend of alginate and gelatin, provided the viscosity and stability required to 3D print – or bioplot – the 2x2cm structure. This not only gave the scaffold the right mechanical properties to match pancreatic tissue, but also enabled large islet aggregates to be embedded without compromising their viability, structure or aggregation.
These structural and plotting requirements were tricky to get right, however, and affected the performance of the islets. The team found that the tight structure and viscosity required for bioplotting reduced the islets activity and nutrient uptake. This prevented the cells from detecting changes in glucose which is a key function of these cells as it helps them determine when to secrete insulin.
The researchers also discovered that after they dissolved the hydrogel-scaffold, cell functionality could be restored. This indicated that although the islets did not function within the scaffold, the mechanical stress caused by the printing process did not lead to permanent cell damage.
It is still early days, but the development of 3D printed scaffolds is a particularly promising step for islet transplantation, and a great advance for people with Type 1 diabetes. It means that, in the not so distant future, islets could be implanted into people to provide them with insulin. The appropriate printing material could even act as protection against the body’s immune system preventing cell rejection, and therefore the need for immunosuppressant drugs.
So, as is often the case with scientific research, there is still a great deal of work to be done but this door is now open.
Biofabrication. 2015 May 28;7(2):025009. doi: 10.1088/1758-5090/7/2/025009. Fabrication of three-dimensional bioplotted hydrogel scaffolds for islets of Langerhans transplantation. Marchioli G1, van Gurp L, van Krieken PP, Stamatialis D, Engelse M, van Blitterswijk CA, Karperien MB, de Koning E, Alblas J, Moroni L, van Apeldoorn AA.