Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa 904-0412, Japan.
Nanofabrication Team, Engineering Section, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa 904-0412, Japan.
Mater Sci Eng C Mater Biol Appl. 2021 Dec;131:112502. doi: 10.1016/j.msec.2021.112502. Epub 2021 Oct 21.
Conventional applications of transplant technology, applied to severe traumatic injuries of the nervous system, have met limited success in the clinics due to the complexity of restoring function to the damaged tissue. Neural tissue engineering aims to deploy scaffolds mimicking the physiological properties of the extracellular matrix to facilitate the elongation of axons and the repair of damaged nerves. However, the fabrication of ideal scaffolds with precisely controlled thickness, texture, porosity, alignment, and with the required mechanical strength, features needed for effective clinical applications, remains technically challenging. We took advantage of state-of-the-art 2-photon photolithography to fabricate highly ordered and biocompatible 3D nanogrid structures to enhance neuronal directional growth. First, we characterized the physical and chemical properties and proved the biocompatibility of said scaffolds by successfully culturing primary sensory and motor neurons on their surface. Interestingly, axons extended along the fibers with a high degree of alignment to the pattern of the nanogrid, as opposed to the lack of directionality observed on flat glass or polymeric surfaces, and could grow in 3D between different layers of the scaffold. The axonal growth pattern observed is highly desirable for the treatment of traumatic nerve damage occurring during peripheral and spinal cord injuries. Thus, our findings provide a proof of concept and explore the possibility of deploying aligned fibrous 3D scaffold/implants for the directed growth of axons, and could be used in the design of scaffolds targeted towards the restoration and repair of lost neuronal connections.
传统的移植技术应用于神经系统的严重创伤，由于损伤组织功能恢复的复杂性，在临床上的效果有限。神经组织工程旨在利用模仿细胞外基质生理特性的支架来促进轴突的伸长和受损神经的修复。然而，制造具有精确控制的厚度、纹理、孔隙率、取向和所需机械强度的理想支架，对于有效的临床应用来说仍然具有技术挑战性。我们利用最先进的双光子光刻技术制造了高度有序和生物相容的 3D 纳米网格结构，以增强神经元的定向生长。首先，我们对这些支架的物理和化学性质进行了表征，并通过在其表面成功培养原代感觉和运动神经元证明了其生物相容性。有趣的是，与在平板玻璃或聚合物表面观察到的无方向性相反，轴突沿着纤维以高度的取向性延伸到纳米网格的图案中，并且可以在支架的不同层之间进行 3D 生长。观察到的轴突生长模式非常适合治疗外周和脊髓损伤时发生的创伤性神经损伤。因此，我们的发现提供了一个概念验证，并探索了使用定向纤维 3D 支架/植入物来引导轴突生长的可能性，并且可以用于设计针对恢复和修复丧失的神经元连接的支架。
