title: Nanoparticle-based vaginal drug delivery systems for HIV prevention.
abstract: BACKGROUND
  Several strategies are being investigated for the prevention of heterosexual transmission of HIV. Of these, topical vaginal drug delivery systems, microbicides, are being actively pursued. HIV prevention by means of a topical microbicide has several drug delivery challenges. These challenges include the vaginal mucosal barriers and potential degradation of the drugs in the vaginal lumen due to pH and enzymes present. Also, new drugs being evaluated as microbicides have specific mechanisms of action, which in some cases require drug targeting to a specific site of action. Nanoparticles provide a delivery strategy for targeted or controlled delivery to the vagina which can be applied in the field of HIV prevention.
  
  
  METHODS
  This review summarizes nanoparticulate systems and their use in mucosal delivery to date. The sexual transmission of HIV along with the various targets to prevent transmission are discussed as well as the potential opportunities, challenges and advantages in using a nanoparticle-based approach for microbicidal drug delivery.
  
  
  RESULTS
  This review provides a general understanding of vaginal drug delivery, its challenges, and nanoparticulate delivery systems. Additionally, insight will be gained as to the limited existing application of this technology to the field of HIV prevention.
  
  
  CONCLUSIONS
  To date, few studies have been published that exploit nanoparticle-based microbicidal delivery to the vagina. The use of nanoparticles for vaginal drug delivery provides an approach to overcome the existing barriers to success.
authors.affiliation: Magee Women's Research Institute, 204 Craft Avenue, B509, Pittsburgh, PA 15213, USA.
authors.forename: Rama
authors.initials: R
authors.lastname: Mallipeddi
authors.forename: Lisa Cencia
authors.initials: LC
authors.lastname: Rohan
mesh_terms: D019380:Anti-HIV Agents / Q000008:administration & dosage; D016503:Drug Delivery Systems; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D006801:Humans; D053758:Nanoparticles; D014621:Vagina
chemical_list: D019380:Anti-HIV Agents