title: Current status of non-viral gene therapy for CNS disorders.
abstract: BACKGROUND
  Viral and non-viral vectors have been used as methods of delivery in gene therapy for many CNS diseases. Currently, viral vectors such as adeno-associated viruses (AAV), retroviruses, lentiviruses, adenoviruses and herpes simplex viruses (HHV) are being used as successful vectors in gene therapy at clinical trial levels. However, many disadvantages have risen from their usage. Non-viral vectors like cationic polymers, cationic lipids, engineered polymers, nanoparticles, and naked DNA offer a much safer option and can therefore be explored for therapeutic purposes.
  
  
  METHODS
  This review discusses different types of viral and non-viral vectors for gene therapy and explores clinical trials for CNS diseases that have used these types of vectors for gene delivery. Highlights include non-viral gene delivery and its challenges, possible strategies to improve transfection, regulatory issues concerning vector usage, and future prospects for clinical applications.
  
  
  CONCLUSIONS
  Transfection efficiency of cationic lipids and polymers can be improved through manipulation of molecules used. Efficacy of cationic lipids is dependent on cationic charge, saturation levels, and stability of linkers. Factors determining efficacy of cationic polymers are total charge density, molecular weights, and complexity of molecule. All of the above mentioned parameters must be taken care for efficient gene delivery.
authors.affiliation: a Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine , Florida International University , Miami , FL , USA.
authors.forename: Rahul Dev
authors.initials: RD
authors.lastname: Jayant
authors.affiliation: a Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine , Florida International University , Miami , FL , USA.
authors.forename: Daniela
authors.initials: D
authors.lastname: Sosa
authors.affiliation: a Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine , Florida International University , Miami , FL , USA.
authors.forename: Ajeet
authors.initials: A
authors.lastname: Kaushik
authors.affiliation: a Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine , Florida International University , Miami , FL , USA.
authors.forename: Venkata
authors.initials: V
authors.lastname: Atluri
authors.affiliation: a Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine , Florida International University , Miami , FL , USA.
authors.forename: Arti
authors.initials: A
authors.lastname: Vashist
authors.affiliation: a Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine , Florida International University , Miami , FL , USA.
authors.forename: Asahi
authors.initials: A
authors.lastname: Tomitaka
authors.affiliation: a Center for Personalized Nanomedicine, Department of Immunology, Herbert Wertheim College of Medicine , Florida International University , Miami , FL , USA.
authors.forename: Madhavan
authors.initials: M
authors.lastname: Nair
mesh_terms: D002412:Cations / Q000737:chemistry; D002493:Central Nervous System Diseases / Q000628:therapy*; D004247:DNA / Q000008:administration & dosage; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D008055:Lipids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D014162:Transfection
chemical_list: D002412:Cations; D008055:Lipids; D011108:Polymers; D004247:DNA
keywords: Gene delivery; brain delivery; central nervous system; nanobiotechnology; neurological disorders; viral/non-viral vector