One of the most challenging neurodegenerative disorders is Parkinson's disease (PD) with over 10 million people affected worldwide. PD characteristics are the loss of dopaminergic neurons in the substanitia nigra, coupled with a motoric disorder. Many dopamine replacement treatments exist with beneficial motor result, however they cause adverse effects due to their non-physiological nature and off-target release. Another promising strategy to handle such ailment is cell-based therapies. Here, dopaminergic cells are injected into the desired site to regain function. However, several challenges limit the success of the treatment. First, dopaminergic cells are scarce and cannot be obtained for therapy. Second, if dopaminergic cells are injected into affected brains, where highly pro-apoptotic surroundings exist, the lack of a supporting, biocompatible microenvironment will prevent cells' integration with the host, hampering their survival. Therefore, cell encapsulation in a protective microenvironment would significantly increase the chances for a successful treatment. Furthermore, the increased usage in stem cell-derived dopaminergic neurons, which are immature by their propagative nature, is a limiting factor. Consequently, the need to form highly developed dopaminergic tissues, which possess all the traits found in these functional neurons is of highest importance.
In this study we propose a novel approach to form personalized dopaminergic tissue implants. These implants are fully functional, expressing dopaminergic markers and are electrically active. Furthermore, these implants secrete dopamine, which can be modulated and increased by incorporating gold nano-rods into the supporting material, throughout the differentiation procedure. We believe that these personalized implants with increased dopamine secretion could protect the injected cells and relapse the negative effects of the disease. Furthermore, since the supporting microenvironment is built from patient-specific materials, the function of the implants will not be jeopardized by an immune response and rejection.