3D printed neural stem cells offer hope for repairing brain injuries
Researchers have developed a method that offers the potential for customized treatments for brain injuries by showcasing the ability to 3D print stem cells to replicate the intricate structure of the cerebral cortex.
Tissue engineering continues to play an integral role in shaping the field of regenerative medicine. Numerous studies have demonstrated successful tissue engineering approaches to repairing and restoring damaged organs and tissues, such as bone, cartilage and skin. However, recapturing the complexities of structures made up of layered cellular components, e.g., the cerebral cortex, has posed a challenge.
Brain injuries, including those caused by stroke, surgical intervention for brain tumors and epilepsy, can result in damage to the cerebral cortex. This in turn can lead to motor impairment and cognitive dysfunction. Currently, there are no effective therapies for brain injuries.
Regenerative therapies for tissue repair, particularly those involving the use of a patient’s own stem cells for implantation, hold great potential as a future avenue for treating brain injuries. However, a significant challenge has been the absence of a reliable method to ensure that these implanted stem cells replicate the intricate structure of the brain.
In the latest developments, a team of researchers from the University of Oxford (UK) has developed a new technique to 3D print neural stem cells to resemble the structure of the brain, specifically the cerebral cortex.
Combining growth factors and chemicals, the researchers induced the differentiation of human induced pluripotent stem cells (hiPSCs) into two neural progenitors. Droplets encompassing the hiPSCs-derived neural progenitors were then 3D printed to form cerebral cortical tissues organized into two layers. When cultured, biomarker expression revealed that the printed tissues maintained their layered cellular structure.
In addition, the team implanted the 3D printed tissues into ex vivo mouse brain slices, where they observed signaling activity along with the projection of nerve processes and migration of neurons. Their observations suggested that the printed tissues had successfully integrated into the brain slices.
Francis Szele, senior author of the study, commented, “The use of living brain slices creates a powerful platform for interrogating the utility of 3D printing in brain repair. It is a natural bridge between studying 3D printed cortical column development in vitro and their integration into brains in animal models of injury.”
This study provides a technical foundation for personalized implants for brain injuries that use 3D tissues created from a patient’s own induced pluripotent stem cells. Looking ahead, the researchers are now working to improve their droplet printing technique to produce complex multi-layer cerebral cortex tissues, mimicking the human brain.
Linna Zhou, senior author of the study, added: “Our droplet printing technique provides a means to engineer living 3D tissues with desired architectures, which brings us closer to the creation of personalized implantation treatments for brain injury.”