Scientists from Tomsk Polytechnic University (TPU), in collaboration with Russian colleagues, have developed biomedical scaffolds with a gyroid structure that exhibit shape memory effect at physiological temperature. This property makes the material promising for bone tissue engineering, enabling minimally invasive implantation and potentially improving its integration with bone.
The scaffolds are created using 3D printing from biodegradable polylactide plasticized with polyethylene glycol. The addition of 10 wt.% polyethylene glycol reduced the glass transition temperature of polylactide to 36–39 °C, allowing it to "remember" its shape when heated to body temperature. According to laboratory data, the scaffolds restore their original shape by 97% in 6 minutes at 40 °C due to the porous gyroid structure, which ensures uniform heat exchange and fluid penetration.
The principle of the scaffold's operation is as follows: a biodegradable scaffold is formed according to the shape of the bone defect, then compressed and cooled to obtain a temporary compact shape. During the operation, the surgeon inserts the implant through a small incision, and when heated to body temperature, the scaffold expands, precisely filling the defect without mechanical adjustment. If necessary, additional local soft heating can be used in clinical settings.
Previously, similar studies were conducted at higher temperatures (above 60 °C), which was unacceptable for living tissues. The new development allows the shape memory effect to be safely applied directly in the human body.