The potential for 3D bioprinting has been further expanded thanks to the work of engineers from the University of New South Wales (UNSW), who have developed a soft robotic arm that can print directly onto organs and tissues inside the human body.
In recent years, using 3D printing technology to create biomaterials that incorporate living cells (bioinks) and drugs has emerged to treat a range of conditions by creating, for example, cardiac or gastrointestinal patches.
Currently, bioprinting is used mostly for research and for developing new drugs. It requires the use of large 3D printers to create constructs that are surgically implanted into the body, which carries its own risks, including tissue injury and the risk of infection. Because biomaterials are usually soft, fragile structures, they have the potential to be damaged by manual handling during the implantation process.
Another common challenge in using externally created 3D constructs is that there can be a mismatch between the construct and the tissue surface it is implanted onto. Implanting biomaterials directly onto target tissues provides a promising solution.
Engineers from UNSW have developed a miniature, flexible soft robotic arm that can be inserted into the body like an endoscope and deliver biomaterials directly onto the surface of organs and tissues.
The proof-of-concept device, called F3DB, is externally controlled and comprises a long, flexible robotic arm, at the end of which sits a highly maneuverable swivel head that "prints" the bioink through a miniature, multidirectional nozzle.
“Existing 3D bioprinting techniques require biomaterials to be made outside the body and implanting that into a person would usually require large open-field surgery which increases infection risks,” said Dr Thanh Ngo Do, corresponding author of the study.
“Our flexible 3D bioprinter means biomaterials can be directly delivered into the target tissue or organs with a minimally invasive approach,” Do said. “Our prototype is able to 3D print multilayered biomaterials and different sizes and shapes through confined and hard-to-reach areas, thanks to its flexible body.”
Once the F3DB is done printing in one area, it can be steered to another location to begin the process again. This means the device can be used to print biomaterials over wide areas, including the whole surface of organs such as the colon, stomach, heart, and bladder, something that cannot be done with current bioprinting devices.
The engineers tested the F3DB outside the body on flat and curved surfaces, including inside an artificial colon and on the surface of a pig’s kidney, using chocolate, composite gel, and biomaterials to accurately print different shapes.
Importantly, they found that cells were not affected by the printing process, and after printing, the majority of cells were still alive.
In addition to printing biomaterials, the device operates as a regular endoscopic device, cleaning structures using water jets, marking lesions, and dissecting tissues.
“Compared to the existing endoscopic surgical tools, the developed F3DB was designed as an all-in-one endoscopic tool that avoids the use of changeable tools which are normally associated with longer procedural time and infection risks,” said Mai Thanh Thai, lead author of the study.
Currently, no commercially available devices can print onto internal tissues and organs. The team behind the F3DB say that with further development, the device should be ready for use by healthcare professionals within five to seven years.
The study was published in the journal Advanced Science.