Neural prostheses use the principle of technical excitability of nerves by means of electrical stimulation and the feedback of bioelectrical to restore body functions in neurological rehabilitation. Besides general consideration of the cytotoxicity and the biostability of the materials used for the implants, special attention should be drawn on the interface between the implant and the surrounding tissue. Apart from the mechanical interaction between encapsulation tissue and implant, we discuss three aspects of biological-chemical interactions at the neuro-technical interface: the modification of interface surfaces, the modification of neural cell properties and the replacement of technical by biological materials.