5 Biological preparations for gene therapy; adeno-associated virus (AAV) gene therapy preparations and pharmaceuticals; Biological preparations for treatment of neurological diseases and disorders; antibody and gene therapy preparations for treatment of disease, namely, neurological diseases; medical preparations and pharmaceuticals for treatment of neurological diseases via antibody, gene replacement, gene knockdown, or vectorized antibodies; antibody and gene therapy preparations for neurological diseases; nucleic acids encoding polypeptides for gene therapy; Drug delivery agents comprising compounds that facilitate delivery of a wide range of pharmaceuticals and biotherapeutics; Drug delivery agents comprising capsids viral platforms, and non-viral platforms, that facilitate delivery of a wide range of pharmaceuticals and biotherapeutics; pharmaceutical for the treatment of neurodegenerative diseases and diseases of the central nervous system, Alzheimer's disease, amyotrophic lateral sclerosis (ALS), Parkinson's disease, Friedreich's Ataxia, Huntington's disease, and prion disease