Embryonic stem cells (ESC) can survive even when inserted into chains of polymers, in a process in which they are “weaved” into artificial and flexible tissues able to adapt to various types of transplants. In an innovative technique, stem cells could be used in the future to produce artificial organs, say researchers at University College London.
The technique was described in a study, published in Integrative Biology. It implements other research to shape living cells into engineered tissues, including a technique which would print a live tissue using an ink printer, which would substitute normal ink with a biological ink made up of cells.
This technique has already underwent various changes to minimize damage to biological tissue. With this technology it has been possible to ‘weave’ a network of threads containing live brain cells. In this new research, Suwan Jayasinghe and her colleagues have demonstrated that this is possible with a similar technique, to create embryonic stem cell ‘threads’.
This is, say the scientists, speaking about the new technology, a technology called “electrospraying”, in which two stainless steel needles, one inside of the other, join a viscous and biodegradable network of polymers with a suspension of embryonic stem cells. Applying an electrical current to the needles charges the string of polymers and the cells, which accelerate towards a copper ring located below.
When the cells and polymers exit from the ring, they become a single, fine string. Sheets of different sizes can be formed, simply by crossing the thread repeatedly on a flat surface, while passing the thread over a mold allows the scientists to obtain a three-dimensional shape. The polymer needs to be viscous in order to keep the tissue united. Using DNA amplification techniques, Jayasinghe and his colleagues have demonstrated that the cells in the structure preserved the intact genes of the undifferentiated stem cells, and that electrosprayed genes and genes from normal cell cultures were expressed in the same way. This is important evidence that demonstrates that even after the treatment the stem cells were still alive.
The researchers reported in New Scientist magazine that the tissue made out of embryonic stem cells rather than specialized cells have greater possibilities of being transplanted into a more diverse array of sites in the body. Once these cells are implanted, thanks to their flexibility, they develop based on where they have been implanted or can be influenced by drugs to convert them into the desired tissue depending on the circumstances. It has also been observed in experiments that over time embryonic stem cells survive and grow, forming coherent tissues, while the polymer breaks down and slowly disappears.