The birth of a new concept
The main innovation of the DISP platform is its spatial and temporal controllable for polymerization reactions. The team obtained precise control of the polymerization position of the material by introducing the combination of targeted ultrasound and cryosensible liposomes. Liposomes are a current drug administration vehicle that has been used as a miniature container for retication agents in this study and which were then incorporated into bioinks. Ink also contains polymer monomers, a development contrast agent and active substances to deliver, such as drugs, cells or conductive materials (such as carbon nanotubes, silver particles, etc.).
After the injection, by increasing the temperature of the target zone by around 5 ° C, ultrasound triggers the liposome to release the retication agent, thus starting the local polymerization process to reach “in situ formation” in vivo.
To obtain visual monitoring of in vivo polymerization reactions, the team also introduced a protein “airbag” derived from bacteria as an ultrasonic contrast agent. These vesicles filled with air are not only clearly visible in the image, but also feel the changes in the material of the liquid in the frost. Thanks to the analysis of imaging contrast, researchers can judge in real time if the aggregation is complete and if the printing is successful, considerably improving the precision and safety of in vivo operations.
Delivery of drugs and future clinical perspectives
In the verification experience, the search team used the DISP platform to print a drug hydrogel charged with doxorubicin in the area around the bladder tumor. The results show that compared to the injection of traditional drugs, this method can considerably improve the apoptosis rate of local tumor cells.
“We have demonstrated the effectiveness of the DISP in small animal models for tumor treatment,” said Gao Wei, professor at the Caltech medical engineering department. “The next step will be to extend to large animal models and ultimately stimulate clinical transformation.” In addition, the team also explores the integration of artificial intelligence with the DISP platform to improve its automatic positioning and its real-time printing capacities in dynamic organs such as the heart. “In the future, we hope to make a really independent impression in the body with automatic learning,” he said.
In fact, research on sound 3D printing has long been explored. For example, as early as June 2022, the Concordia University’s research team offered “Direct Sound Printing (DSP)” technology, which carries out spatial positioning and hardening of liquid resins by ultrasound, showing the potential to use sound waves to create complex structures for the first time. The result was published in Nature Communications. Then, in October 2024, the school researchers also proposed “Holographic DSP, HDSP”, which reached the impression without contact with greater precision by building a three -dimensional sound field, and was also published in “Natural Communications”.
The DISP platform developed by California Institute of Technology inherits not only the technical path of ultrasonic printing, but also grows it to deep tissue printing in life environments, and has the real possibility of a preclinical application.
