A research team from the California Institute of Technology in the United States has recently made breakthrough progress in the field of medical 3D printing. They have developed a new technology that can directly manufacture medical implants and customized treatment tissues in the body without the need for traditional invasive surgery. This technology has opened up new directions for future precision medicine. The results were published in the latest issue of the journal Science. This new technology is called "Imaging guided deep tissue in vivo ultrasound printing" (DISP), which combines focused ultrasound with specially designed "ultrasound ink" to accurately manufacture biomaterials deep in the body. Researchers say that this technology has the potential to completely change the way personalized medicine is delivered, providing safer and more precise solutions for disease treatment. At present, 3D bioprinting technology has shown great potential in the medical field. However, when printing personalized implants, most existing methods still require surgical implantation of printed materials into the body, which poses problems such as high trauma and risk. In contrast, DISP technology adopts a new idea: use focused ultrasound to trigger the gel reaction of biological ink, so as to achieve in situ printing at the target site. This "ultrasound ink" is composed of biopolymers, imaging contrast agents, and thermosensitive liposomes, which can be delivered to deep tissues in the body through injection or catheterization. In the DISP system, an automatic positioning ultrasonic transducer works according to the preset digital model, and generates local slight heat (slightly higher than the body temperature) at the designated position, which urges the liposome to release the crosslinker, thus triggering rapid gel curing of the ink. The entire process is not only precise and controllable, but also monitored in real-time using imaging technology. In addition, the bio ink used in this technology has high adjustability. People can design its performance according to their needs, such as enhancing conductivity, achieving drug release, promoting tissue adhesion, and even having real-time imaging capabilities, providing flexible solutions for the treatment of various diseases. In the experiment, the team successfully printed drug loaded functional biomaterials near bladder tumors in mice and deep muscle tissues in rabbits, verifying the potential of DISP in drug delivery, tissue repair, and bioelectronic device construction. The safety assessment showed that the technology did not cause obvious inflammation or tissue damage, and the gel ink would not be naturally cleared by the body within a week, with good biocompatibility. The team stated that with the continuous improvement of technology, this innovation is expected to be widely applied in clinical practice in the future, truly realizing the vision of "in vivo printing and non-invasive treatment". The biomedical field is an important application of 3D printing technology: firstly, bones, heart stents, etc. that are precisely matched with the patient's body are printed outside the body, and then implanted into the patient's body, providing the possibility for personalized medicine. However, this approach still cannot relieve patients of the pain of undergoing surgery. In contrast, achieving precise printing of biomaterials directly in the body effectively fills this gap. In the future, with the combination of artificial intelligence real-time path planning and other technologies, the medical community is expected to completely transform the traditional mode of 3D printed biomaterials in vitro construction and surgical implantation, and promote the development of personalized medicine to the next level. (New Society)