5 Pharmaceuticals; pharmaceutical preparations and substances; pharmaceutical preparations, namely, a drug delivery system comprising genetically engineered or purified exosomes for therapeutic use; pharmaceutical preparations, namely, exosomes to deliver protein or nucleic acids or viral vectors for therapy; medicine; medical preparations and articles; biological preparations for medical purposes; biological preparations for the treatment of cancer, diabetes, obesity, metabolic syndrome, dementia, and other aging associated pathologies such as mitochondrial disease, joint/ligament strain/tears, muscle atrophy, muscular dystrophy, neuromuscular diseases, neurological disorders, neurodegenerative disorders, inflammatory disorders, infectious diseases, genetic diseases, rare diseases, in-born errors of metabolism (IEMs), lysosomal storage disorders and urea cycle disorders; biological preparations comprising exosome; biological preparations comprising a therapeutic target protein-loaded, nucleic acid-loaded or virus-loaded exosome; biological preparations comprising exosome for use in the manufacture of pharmaceuticals; biological reagents for medical use; mixed biological preparations for medical purposes; mixed biological preparations for the prevention and treatment of infectious diseases; diagnostic reagents for medical use; medical diagnostic reagents comprising exosome; pharmaceuticals, medicines, biologics, biotherapeutics, biosimilars and therapeutics, namely, EV-based nucleic acid therapeutics for the prevention and treatment of infections or disease; diagnostic kits comprised of medical diagnostic reagents and assays for testing of bodily fluids for use in disease detection; diagnostic kits comprised of medical diagnostic reagents and assays for testing of exosomes for use in disease detection; diagnostic kits comprised of medical diagnostic reagents and assays that test for the presence of cancer, diabetes, obesity, metabolic syndrome, dementia, and other aging associated pathologies such as mitochondrial disease, joint/ligament strain/tears, muscle atrophy, muscular dystrophy, neuromuscular diseases, neurological disorders, neurodegenerative disorders, inflammatory disorders, infectious diseases, genetic diseases, rare diseases, in-born errors of metabolism (IEMs), lysosomal storage disorders and urea cycle disorders