title: Endosomal trafficking of nanoformulated antiretroviral therapy facilitates drug particle carriage and HIV clearance.
abstract: Limitations of antiretroviral therapy (ART) include poor patient adherence, drug toxicities, viral resistance, and failure to penetrate viral reservoirs. Recent developments in nanoformulated ART (nanoART) could overcome such limitations. To this end, we now report a novel effect of nanoART that facilitates drug depots within intracellular compartments at or adjacent to the sites of the viral replication cycle. Poloxamer 407-coated nanocrystals containing the protease inhibitor atazanavir (ATV) were prepared by high-pressure homogenization. These drug particles readily accumulated in human monocyte-derived macrophages (MDM). NanoATV concentrations were ∼1,000 times higher in cells than those that could be achieved by the native drug. ATV particles in late and recycling endosome compartments were seen following pulldown by immunoaffinity chromatography with Rab-specific antibodies conjugated to magnetic beads. Confocal microscopy provided cross validation by immunofluorescent staining of the compartments. Mathematical modeling validated drug-endosomal interactions. Measures of reverse transcriptase activity and HIV-1 p24 levels in culture media and cells showed that such endosomal drug concentrations enhanced antiviral responses up to 1,000-fold. We conclude that late and recycling endosomes can serve as depots for nanoATV. The colocalization of nanoATV at endosomal sites of viral assembly and its slow release sped antiretroviral activities. Long-acting nanoART can serve as a drug carrier in both cells and subcellular compartments and, as such, can facilitate viral clearance.
  
  
  OBJECTIVE
  The need for long-acting ART is significant and highlighted by limitations in drug access, toxicity, adherence, and reservoir penetrance. We propose that targeting nanoformulated drugs to infected tissues, cells, and subcellular sites of viral replication may improve clinical outcomes. Endosomes are sites for human immunodeficiency virus assembly, and increasing ART concentrations in such sites enhances viral clearance. The current work uncovers a new mechanism by which nanoART can enhance viral clearance over native drug formulations.
authors.affiliation: Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA.
authors.forename: Dongwei
authors.initials: D
authors.lastname: Guo
authors.affiliation: Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Computer and Electronics Engineering, University of Nebraska-Lincoln, Omaha, Nebraska, USA.
authors.forename: Tadeusz A
authors.initials: TA
authors.lastname: Wysocki
authors.affiliation: Department of Computer and Electronics Engineering, University of Nebraska-Lincoln, Omaha, Nebraska, USA.
authors.forename: Beata J
authors.initials: BJ
authors.lastname: Wysocki
authors.affiliation: Department of Neurology, Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, New York, USA.
authors.forename: Harris A
authors.initials: HA
authors.lastname: Gelbard
authors.affiliation: Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA.
authors.forename: Xin-Ming
authors.initials: XM
authors.lastname: Liu
authors.affiliation: Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA.
authors.forename: JoEllyn M
authors.initials: JM
authors.lastname: McMillan
authors.affiliation: Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA hegendel@unmc.edu.
authors.forename: Howard E
authors.initials: HE
authors.lastname: Gendelman
mesh_terms: D044966:Anti-Retroviral Agents / Q000493:pharmacokinetics* / Q000494:pharmacology; D000069446:Atazanavir Sulfate; D001692:Biological Transport; D002478:Cells, Cultured; D011992:Endosomes / Q000378:metabolism*; D016655:HIV Core Protein p24 / Q000032:analysis; D015497:HIV-1 / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008962:Models, Theoretical; D053758:Nanoparticles; D009842:Oligopeptides / Q000493:pharmacokinetics* / Q000494:pharmacology; D020442:Poloxamer / Q000493:pharmacokinetics* / Q000494:pharmacology; D011725:Pyridines / Q000493:pharmacokinetics* / Q000494:pharmacology; D014776:Virus Cultivation
chemical_list: D044966:Anti-Retroviral Agents; D016655:HIV Core Protein p24; D009842:Oligopeptides; D011725:Pyridines; D020442:Poloxamer; D000069446:Atazanavir Sulfate