Tiny, 3D-printed bricks have been designed to heal broken bones and could one day lead to lab-made organs for human transplant. Inspired by LEGO® blocks, the small, hollow bricks serve as scaffolding onto which both hard and soft tissue can regrow better than today's standard regeneration methods.
Each brick is 1.5 mm3, or roughly the size of a small flea. The scaffolding can be stacked together like LEGOs and placed in thousands of different configurations to match the complexity and size of almost any situation.
Orthopedic surgeons typically repair more complex bone fractures by implanting metal rods or plates to stabilize the bone and then inserting biocompatible scaffolding materials packed with powders or pastes that promote healing. A unique advantage of the new scaffolding system is that its hollow blocks can be filled with small amounts of gel containing various growth factors that are precisely placed closest to where they are needed. Growth-factor-filled blocks placed near repaired rat bones led to about three times more blood vessel growth than conventional scaffolding material.
The 3D-printed microcage technology improves healing by stimulating the right type of cells to grow in the right place at the right time. Different growth factors can be placed inside each block, enabling more precise and quicker repair tissue.
The small devices are modular and can be assembled to fit into almost any space. When piecing together block segments containing four layers of four bricks by four bricks, the researchers estimate more than 29,000 different configurations can be created. They also envision that the 3D-printed technology could be used to heal bones that have to be cut out for cancer treatment, for spinal fusion procedures, and to build up weakened jaw bones ahead of a dental implant.
By changing the composition of the technology's 3D-printed materials, it could also be used to build or repair soft tissues. With significantly more research, the researchers hope the modular microcage approach could even be used to make organs for transplant.