Preparation of a bioactive cochlea implant electrode by electrophoretic deposition of DNA-functionalized nanoparticles

到目前为止，还没有对dna转染纳米颗粒在耳蜗植入电极上的涂层进行研究。在这个项目中，电极将被纳米颗粒包裹，纳米颗粒携带编码蛋白质NT-3和BDNF的DNA，并在体外进行研究。表面介导的转染将导致NT-3和BDNF释放到周围组织中。这将促进神经突向电极的生长，提高患者的听力能力。为此，需要研究纳米颗粒的物理、化学和生物学特性（特别是转染效率和细胞毒性）。然后，dna功能化的纳米颗粒将通过电泳沉积在衬底的不同层上。将研究不同层的表面介导转染（纳米颗粒的顺序释放）的效率。目的是研究在螺旋神经节细胞培养中沉积的功能化纳米颗粒。由于螺旋神经节细胞是最终分化的细胞，我们将从新生小鼠耳蜗中获得螺旋神经节细胞，并在分离细胞培养中进行研究。NT-3和BDNF转染是否成功还有待观察。最后，准备螺旋神经节外植体的培养。它们将在纳米颗粒涂层的耳蜗植入电极上共同培养。我们将研究神经突向功能化电极的生长是否会增强。特别重要的是神经突的生长行为和神经突与雪旺细胞作为再生促进剂的相互作用。

So far, no study on the coating of a Cochlea-Implant electrode with DNA-transfecting nanoparticles has been performed. In this project, an electrode shall be coated with nanoparticles that carry DNA encoding for the proteins NT-3 and BDNF and studied in vitro. A surface-mediated transfection will lead to a release of NT-3 and BDNF into the surrounding tissue. This will enhance the growth of neurites towards the electrode and improve the hearing ability of the patient. For this, the physical, chemical and biological properties of the nanoparticles (especially transfection efficiency and cytotoxicity) shall be studied. Thereafter, the DNA-functionalized nanoparticles will be deposited by electrophoretic deposition in different layers on the substrate. The efficiency of the surface-mediated transfection from different layers (sequential release of nanoparticles) will be studied. The goal is the investigation of the deposited functionalized nanoparticles in a spiral ganglial cell culture. As spiral ganglia cells are finally differentiated cells, they will be obtained from neonatal mouse cochlea and studied in a dissociated cell culture. It will be determined whether the transfection with NT-3 and BDNF is successful. Finally, cultures of spiral ganglia explants will be prepared. They will be co-cultured on a nanoparticle-coated Cochlea-Implant electrode. It will be investigated whether the growth of neurites towards the functionalized electrode is enhanced. Especially important are the neurite growth behavior and the interaction of neurites with Schwann cells as promotors of regeneration.