Institute of Polymer Science and Engineering, National Taiwan University, Taipei, Taiwan, ROC.
Department of Biochemical Science and Technology, National Taiwan University, Taipei, Taiwan, ROC.
Biomaterials. 2018 Aug;174:31-40. doi: 10.1016/j.biomaterials.2018.05.014. Epub 2018 May 9.
Optogenetics offers unique, temporally precise control of neural activity in genetically targeted specific neurons that express light-sensitive opsin molecules. Three-dimensional (3D) delivery of optogenetics can be realized by co-injection of bacteriorhodopsin (HEBR) plasmid with a chitosan-based self-healing hydrogel with strong shear-thinning properties. The HEBR protein shows photoelectrical properties and can be used as an optical switch for cell activation. We optimize the shear force generated during the process of injection (∼100 Pa), which is transient because of the self-healing nature of the hydrogel. This transient force exerted by the self-healing hydrogel may allow the cytosolic delivery of HEBR plasmid with excellent cell viability and a high efficiency approaching 80%. When excited with green light, HEBR-delivered neural stem cells (NSCs) can proliferate and specifically differentiate into neurons in vitro and rescue the function of nerve impaired zebrafish in vivo. This novel optogenetic method combining 3D injectable self-healing hydrogel offers potential temporal-spatial approaches to treat neurodegenerative diseases in the future.
光遗传学提供了一种独特的、时间精确的基因靶向特定神经元的神经活动控制方法，这些神经元表达对光敏感的视蛋白分子。通过将细菌视紫红质 (HEBR) 质粒与具有强剪切稀化特性的壳聚糖基自修复水凝胶共注射，可以实现三维 (3D) 光遗传学传递。HEBR 蛋白具有光电特性，可用作细胞激活的光开关。我们优化了注射过程中产生的剪切力（约 100 Pa），由于水凝胶的自修复特性，这种剪切力是短暂的。这种自修复水凝胶产生的瞬态力可能允许细胞质内递送 HEBR 质粒，同时保持良好的细胞活力和接近 80%的高效率。用绿光激发时，递送至神经干细胞 (NSCs) 的 HEBR 可以在体外增殖并特异性分化为神经元，并在体内挽救受损神经的斑马鱼的功能。这种将 3D 可注射自修复水凝胶与光遗传学相结合的新方法为未来治疗神经退行性疾病提供了潜在的时空方法。
