They've developed a gun that prints 3D bones during surgery and will help create live implants in operating rooms.

A team of researchers from Sungkyunkwan University in Seoul, South Korea, has developed a portable device that allows bone grafts to be printed directly onto fractures during surgery. The breakthrough, published in the Cell Press journal Device , represents an important step forward in the field of regenerative medicine and could transform the way complex bone injuries are treated.

The tool, similar to a silicone gun, uses an in-situ 3D printing system that allows the graft to be manufactured directly on the damaged bone , adapting to its irregular shape without the need for prefabricated parts or prior laboratory procedures. This speeds up the surgical process and improves the anatomical integration of the implant.

According to the article, the device works by hot-extruding a filament composed of hydroxyapatite (a mineral found in natural bone) and polycaprolactone , a biocompatible thermoplastic. This mixture can be applied directly to the fracture without damaging soft tissue.

The system was tested in animal models, specifically in rabbits with severe femoral fractures. According to Newsweek, the results showed a significant improvement in bone regeneration and graft integration compared to traditional methods based on bone cement.

At 12 weeks, treated animals showed greater volume of new bone, increased cortical thickness , and improved structural strength parameters, with no signs of infection or injury to nearby tissues.

Furthermore, the filament used incorporates antibiotics such as vancomycin and gentamicin, which are released in a controlled manner within the implant. This local approach makes it possible to prevent postoperative infections without resorting to systemic antibiotics, thus reducing the risk of side effects and bacterial resistance. In vitro tests confirmed its efficacy against common bacteria such as Escherichia coli and Staphylococcus aureus.

One of the system's main advantages is its ability to be customized during the procedure. The surgeon can control the shape, depth, and direction of the graft in real time, making it a practical solution for treating complex or irregularly shaped bone defects.

According to the study's authors, this approach overcomes many of the limitations of current techniques: it reduces surgical times, eliminates the need to prepare implants in advance, and improves the morphological adaptation of the graft to the damaged bone.

The device also offers multifunctionality: it can print bone scaffolds of various sizes and shapes , optimized to promote osteoconduction (new tissue growth), biological integration, and infection prevention.

Despite the encouraging results, the researchers emphasize that clinical application in humans is still a long way off. The next step will be to validate the procedure in larger animals , develop standardized industrial processes, and meet regulatory requirements regarding sterilization and long-term safety.

The team is already working on improving the filament's antibacterial properties, expanding its functionality, and strengthening the technical process before beginning clinical trials.