Ultrasound waves can penetrate through thick tissues and print medical implants inside a body, experiments in animals suggest.
Researchers created 3D implants using focused ultrasound and ultrasound-responsive bioinks delivered via injection or catheter.
The carefully guided ultrasound waves trigger localized heating, slightly above body temperature, that transforms the ink into a gel that can be printed into desired shapes and tailored for functions such as drug delivery and tissue replacement, according to a report published on Thursday in Science.
Furthermore, the ultrasound imaging allows for real-time monitoring and customized pattern creation, the researchers said.
In one experiment, the researchers printed drug-loaded biomaterials that delivered a chemotherapy to cancerous sites in a mouse bladder. They found substantially more tumor cell death for several days compared to animals that received the drug through direct injection.
"We have already shown in a small animal that we can print drug-loaded hydrogels for tumor treatment," study leader Wei Gao of Caltech said in a statement. "Our next stage is to try to print in a larger animal model, and hopefully, in the near future, we can evaluate this in humans."
A commentary published with the paper notes that refinements are still needed.
“Printing on organs that expand and contract, such as the lungs, heart, and stomach, presents additional challenges,” the commentary authors note.
