Researchers at Penn State have developed a supportive gel that allows for printing of complex shapes using cell aggregates. The gel provides a supportive matrix during the printing process, and permits the researchers to place the aggregates wherever they want. This technique could pave the way for printed replacements for tissues and organs. Bioprinting, where cell aggregates, such as organoids, are printed to form complex shapes, holds significant promise for regenerative medicine. Simply printing replacement tissues or organs is a tantalizing idea. However, the process is delicate, and so far, it has been challenging to create complex shapes, limiting the potential of the technique. “The reason why this is important is that the current cell aggregate bioprinting techniques can’t make complicated configurations and is mostly in 2D and 3D thin films or simple configurations,” said Ibrahim T. Ozbolat, a researcher involved in the new study published in journal Communications Physics. “If we want complicated 3D, we need a supportive field.” These researchers developed a yield stress gel to provide a supportive matrix. Under normal conditions, the gel is semi-solid, but when subjected to a force, it changes to become liquid. These properties allow a bioprinting system to deposit a cell aggregate within the gel and then withdraw, leaving the aggregate in place. The printing system consists of an aspiration nozzle that can grab and release cell aggregates. The nozzle can create enough force to easily deposit them within the gel, before withdrawing and allowing the gel to rapidly self-heal. Later, the gel can be removed. “We tried two different types of gels, but the first one was a little tricky to remove,” said Ozbolat. “We had to do it through washing. For the second gel, we used an enzyme that liquefied the gel and removed it easily.” The technique is still under development, but in the future it may allow the researchers to create complex shapes that are useful for implantation in the body. Source
