A new kind of hydrogel based on cold soluble gelatine brings 3D printing of artificial organs one step closer. The new hydrogel makes printing artificial tissues easier and cheaper. The researchers behind this new hydrogel hope it can help researchers print artificial organs.
There is a worldwide shortage of donor organs. Figures from the Dutch Transplant Foundation show that on 31 December 2016, 1,071 people were on the waiting list for a donor organ. This includes only patients who could handle surgery at that time, which is called 'transplantable'. In comparison, a total of 1,266 transplants were performed in the same year.
3D printing organs and tissue
3D printing of artificial organs has long been experimented with, which is seen as a possible solution to the global shortage of organs for organ transplants. This involves the use of 'bio-ink', a material based on biological materials that can be printed using a special type of 3D printer. One of these biological materials is gelatin methacrylate (GeIMA), a hydrogel based on living cells.
"A major drawback of conventional hydrogel is its thermal instability. Even small changes in temperature can cause significant changes in the viscosity or thickness of the material," said Dr Keekyoung Kim, a researcher in the School of Engineering at the Okanagan campus of the American University of British Columbia (UBC Okanagan). "This is a problem for many bioproduction systems that operate at room temperature, are only compatible with a limited viscosity of hydrogel and need to generate products that are as uniform as possible for them to function correctly."
New types of hydrogels
Researchers have therefore developed two new types of GeIMA-based hydrogels in an attempt to tackle this problem. They are a GeIMA hydrogel based on gelatine made from skin cells of cold-water fish and a hydrogel based on cold-soluble gelatine. The researchers compared these two new hydrogels with the existing hydrogel, which is based on pig skin-based gelatine.
The cold-soluble gelatine-based hydrogel in particular has shown promising results. This hydrogel appears to be deployable for creating support structures of healthy tissue, on which cells can successfully grow and in which cells can adhere. In addition, the material is thermally stable at room temperature, so its viscosity or thickness is not affected by small temperature fluctuations. The team also demonstrated that using the hydrogel based on cold-soluble gelatine, uniform droplets can be formed at room temperature. This makes tissue printing with this material much easier than with conventional hydrogel.
Lower costs
Another key advantage of cold-soluble gelatine is its substantially lower cost. Primarily used in the food industry, this form of gelatine is three times cheaper than pigskin-based gelatine. This makes it possible to reduce the production costs of bioink.
"We hope this new bio-ink will help researchers create artificial organs and lead to the development of better drugs, tissue engineering and regenerative therapies," Kim said. "The next step is to investigate whether cold-soluble GeIMA-based tissue structures can be used in the long term in both laboratories and real-world transplants."
Others purposes
Producing artificial tissue, by the way, is not the only application for which 3D printers can be used in the medical sector. Earlier this year, for instance, researchers at the University of Florida succeeded in developing a 3D printing technology that can print medical implants and attachments. This production method provides both stronger, cheaper, more flexible and more comfortable implants than traditional manufacturing methods. More information on this technique can be found here.
Author: Wouter Hoeffnagel
Source: UBC Okanagan
Source: Dutch Transplant Foundation
