Breakthrough T1D is committed to developing cell replacement therapies that will one day offer cures for type 1 diabetes (T1D). One goal is to explore technologies to recombine living cells, biomaterials, and molecular factors to create a functional pancreas. That’s why top researchers, engineers, clinicians, and industry experts in the field of 3D bioprinting recently attended a workshop at Breakthrough T1D’s international headquarters in New York. The meeting, called The 3D Bioprinting and Development of Cell Therapies to Treat T1D, helped the field’s top minds identify the opportunities and challenges associated with current methods of bioprinting, and also discuss the potential applications of the technology regarding beta cell replacement therapies. By adapting methods used in traditional 3D printing, one can use cells, growth factors, and biomaterials as inks to fabricate in vitro tissue models for research and, one day, implantation into people with T1D.
“Theoretically, we could build any type of tissue we want; it’s a matter of identifying the best component or bioink, including the cells and the right materials, to print the structure,” says Jaime Giraldo, Ph.D., a program scientist in research at Breakthrough T1D.
Are all currently available 3D bioprinters similar? Researchers first “hacked” a traditional inkjet bioprinter. These inkjet bioprinters have higher resolution and can deliver multiple types of cells, but they can only make tissues of a certain size because of the time they take to print. And, they do not work with all materials. Other bioprinters use different methods to allow ink containing cells to create large structures with various materials. The resolution is quite low, however, and since they use high pressure and speed, the cells can be killed by the forces they experience during the process. Light-based printing, such as with lasers, is a third approach.
The final results should be more mature ‘cellular products’ for beta cell replacement as a functional cure for T1D.
“I am very excited about the laser-assisted bioprinting technology,” says Francesca Spagnoli, Ph.D., group leader at the Centre for Stem Cells and Regenerative Medicine, King’s College London. “It allows high control and resolution of cell positioning.”
Spagnoli also says it is important that the technology enables the elements of the pancreatic microenvironment to be integrated in the correct ratio, in a precise and reproducible fashion compared to self-assembly approaches. Though this technique creates the highest resolution, the range of materials that can be used is limited, and the chemistry involved can be toxic to cells. Fortunately, a form of light-based printing called stereolithography has advanced greatly in recent years. Resins that are biocompatible and biodegradeable has led to improvements in implants and will be more useful in the field of regenerative medicine.
Giraldo says that regardless of the printing choice, for now most of the focus is on smaller tissues—sheets, or hollow tissues such as patches or tubes that can re-create functional tissue structures. There are currently limitations on creating larger tissues for human transplantation because of the time required to print them, and the need for understanding the key components to create a long functioning tissue.
Still, this technology is filling in key gaps in research. It allows scientists to build specific structures that could protect implanted cells, increase the survival and function of cells, and support integration of the tissue structure with the recipient once implanted, a key step that would be necessary for cell therapies to work for people with T1D. Also, certain components in the tissue could release drugs locally that would modulate a person’s immune system, or assist in monitoring the implant.
“The final results should be more mature ‘cellular products’ for beta cell replacement as a functional cure for T1D,” says Spagnoli.
We hope so.
