We've recently been hearing a lot about 3D-bioprinting, a technique in which small body parts can be 3D-printed out of biological tissue. Now, new technology promises to make the process quicker and thus more practical than ever.
Ordinarily, bioprinting is performed in a fashion much like regular 3D printing – an object is slowly built up as successive layers of material are deposited one on top of the other. This means that it can take hours or perhaps days to produce even a simple item.
Lately, though, scientists have been experimenting with a faster method of printing a variety of non-biological objects, which is known as volumetric printing. Working with colleagues at the Netherlands' Utrecht University, a team from the Swiss EMPA research institute has adapted that technology to produce body parts measuring up to several square centimeters in size – these parts have included a valve similar to a heart valve, a meniscus, and a complex-shaped section of femur.
The process involves projecting a laser beam down into a slowly-spinning tube that's filled with a stem cell-laden photosensitive hydrogel. By selectively focusing the light energy at specific locations within the tube, it's possible to solidify the gel in those places only, building up the desired three-dimensional object within a matter of seconds. The stem cells are unharmed in the process.
Next, the scientists add endothelial cells, which are the type that line the interior surface of blood vessels. This causes the item to become vascularized, while the stem cells proceed to differentiate into the type of cells needed (i.e: heart cells, bone cells, etc). The finished item may subsequently be utilized either as a replacement in a human recipient, or in medical testing, reducing the need for lab animals.
"This is just the beginning," says Christophe Moser, head of EPFL's Laboratory of Applied Photonics Devices. "We believe that our method is inherently scalable towards mass fabrication and could be used to produce a wide range of cellular tissue models, not to mention medical devices and personalized implants."
The volumetric bioprinting process is described in a paper that was recently published in the journal Advanced Materials, and is demonstrated in the video below.
Source: EPFL