Transformation of dolutegravir into an ultra-long-acting parenteral prodrug formulation.

Ultra-long-acting integrase strand transfer inhibitors were created by screening a library of monomeric and dimeric dolutegravir (DTG) prodrug nanoformulations. This led to an 18-carbon chain modified ester prodrug nanocrystal (coined NM2DTG) with the potential to sustain yearly dosing. Here, we show that the physiochemical and pharmacokinetic (PK) formulation properties facilitate slow drug release from tissue macrophage depot stores at the muscle injection site and adjacent lymphoid tissues following single parenteral injection. Significant plasma drug levels are recorded up to a year following injection. Tissue sites for prodrug hydrolysis are dependent on nanocrystal dissolution and prodrug release, drug-depot volume, perfusion, and cell-tissue pH. Each affect an extended NM2DTG apparent half-life recorded by PK parameters. The NM2DTG product can impact therapeutic adherence, tolerability, and access of a widely used integrase inhibitor in both resource limited and rich settings to reduce HIV-1 transmission and achieve optimal treatment outcomes.

Dolutegravir Inhibition of Matrix Metalloproteinases Affects Mouse Neurodevelopment.

Dolutegravir (DTG) is a first-line antiretroviral drug (ARV) used in combination therapy for the treatment of human immunodeficiency virus type-1 (HIV-1) infection. The drug is effective, safe, and well tolerated. Nonetheless, concerns have recently emerged for its usage in pregnant women or those of child-bearing age. Notably, DTG-based ARV regimens have been linked to birth defects seen as a consequence of periconceptional usages. To this end, uncovering an underlying mechanism for DTG-associated adverse fetal development outcomes has gained clinical and basic research interest. We now report that DTG inhibits matrix metalloproteinases (MMPs) activities that could affect fetal neurodevelopment. DTG is a broad-spectrum MMPs inhibitor and binds to Zn++ at the enzyme's catalytic domain. Studies performed in pregnant mice show that DTG readily reaches the fetal central nervous system during gestation and inhibits MMP activity. Postnatal screenings of brain health in mice pups identified neuroinflammation and neuronal impairment. These abnormalities persist as a consequence of in utero DTG exposure. We conclude that DTG inhibition of MMPs activities during gestation has the potential to affect prenatal and postnatal neurodevelopment.

Lipophilic nanocrystal prodrug-release defines the extended pharmacokinetic profiles of a year-long cabotegravir.

A once every eight-week cabotegravir (CAB) long-acting parenteral is more effective than daily oral emtricitabine and tenofovir disoproxil fumarate in preventing human immunodeficiency virus type one (HIV-1) transmission. Extending CAB dosing to a yearly injectable advances efforts for the elimination of viral transmission. Here we report rigor, reproducibility and mechanistic insights for a year-long CAB injectable. Pharmacokinetic (PK) profiles of this nanoformulated CAB prodrug (NM2CAB) are affirmed at three independent research laboratories. PK profiles in mice and rats show plasma CAB levels at or above the protein-adjusted 90% inhibitory concentration for a year after a single dose. Sustained native and prodrug concentrations are at the muscle injection site and in lymphoid tissues. The results parallel NM2CAB uptake and retention in human macrophages. NM2CAB nanocrystals are stable in blood and tissue homogenates. The long apparent drug half-life follows pH-dependent prodrug hydrolysis upon slow prodrug nanocrystal dissolution and absorption. In contrast, solubilized prodrug is hydrolyzed in hours in plasma and tissues from multiple mammalian species. No toxicities are observed in animals. These results affirm the pharmacological properties and extended apparent half-life for a nanoformulated CAB prodrug. The report serves to support the mechanistic design for drug formulation safety, rigor and reproducibility.

Efavirenz, atazanavir, and ritonavir disrupt sarcoplasmic reticulum Ca2+ homeostasis in skeletal muscles.

While muscle fatigue, pain and weakness are common co-morbidities in HIV-1 infected people, their underlying cause remain poorly defined. To this end, we evaluated whether the common antiretroviral drugs efavirenz (EFV), atazanavir (ATV) and ritonavir (RTV) could be a contributing factor by pertubating sarcoplasmic reticulum (SR) Ca2+ cycling. In live-cell imaging, EFV (6.0 µM), ATV (6.0 µM), and RTV (3.0 µM) elicited Ca2+ transients and blebbing of the plasma membranes of C2C12 skeletal muscle myotubes. Pretreating C2C12 skeletal muscle myotubes with the SR Ca2+ release channel blocker ryanodine (50 µM), slowed the rate and amplitude of Ca2+ release from and reuptake of Ca2+ into the SR. EFV, ATV and RTV (1 nM - 20 µM) potentiated and then displaced [3H] ryanodine binding to rabbit skeletal muscle ryanodine receptor Ca2+ release channel (RyR1). These drugs at concentrations 0.25-31.2 µM also increased and or decreased the open probability of RyR1 by altering its gating and conductance. ATV (≤5 µM) potentiated and >5µM inhibited the ability of sarco (endo)plasmic reticulum Ca2+-ATPase (SERCA1) to hydrolyze ATP and transport Ca2+. RTV (2.5-31.5 µM) dose-dependently inhibited SERCA1-mediated, ATP-dependent Ca2+ transport. EFV (0.25-31.5 µM) had no measurable effect on SERCA1's ability to hydrolyze ATP and transport Ca2+. These data support the notion that EFV, ATV and RTV could be contributing to skeletal muscle co-morbidities in PLWH by modulating SR Ca2+ homeostasis.

Long-acting approaches for delivery of antiretroviral drugs for prevention and treatment of HIV: a review of recent research.

INTRODUCTION: Despite significant advances in treatment and prevention of HIV-1 infection, poor adherence to daily combination antiretroviral therapy (ART) regimens remains a major obstacle toward achieving sustained viral suppression and prevention. Adherence to ART could also be compromised by adverse drug reactions and societal factors that limit access to therapy. Therefore, medicines that aim to improve adherence by limiting ART side effects, frequency of dosing and socially acceptable regimens are becoming more attractive. AREAS COVERED: This review highlights recent advances and challenges in the development of long-acting drug delivery strategies for HIV prevention and treatment. Approaches for extended oral and transdermal deliveries, microbicides, broadly neutralizing antibodies, and long-acting implantable and injectable deliveries are reviewed. EXPERT OPINION: Emerging approaches on long-acting antiretroviral therapies and broadly neutralizing antibody technologies are currently at various stages of development. Such efforts, if successful and become broadly accepted by clinicians and users, will provide newer and simpler options for prevention and treatment of HIV infection.

A year-long extended release nanoformulated cabotegravir prodrug.

Long-acting cabotegravir (CAB) extends antiretroviral drug administration from daily to monthly. However, dosing volumes, injection site reactions and health-care oversight are obstacles towards a broad usage. The creation of poloxamer-coated hydrophobic and lipophilic CAB prodrugs with controlled hydrolysis and tissue penetrance can overcome these obstacles. To such ends, fatty acid ester CAB nanocrystal prodrugs with 14, 18 and 22 added carbon chains were encased in biocompatible surfactants named NMCAB, NM2CAB and NM3CAB and tested for drug release, activation, cytotoxicity, antiretroviral activities, pharmacokinetics and biodistribution. Pharmacokinetics studies, performed in mice and rhesus macaques, with the lead 18-carbon ester chain NM2CAB, showed plasma CAB levels above the protein-adjusted 90% inhibitory concentration for up to a year. NM2CAB, compared with NMCAB and NM3CAB, demonstrated a prolonged drug release, plasma circulation time and tissue drug concentrations after a single 45 mg per kg body weight intramuscular injection. These prodrug modifications could substantially improve CAB's effectiveness.

Synthesis and characterization of a long-acting emtricitabine prodrug nanoformulation.

PURPOSE: A palmitoylated prodrug of emtricitabine (FTC) was synthesized to extend the drug's half-life, antiretroviral activities and biodistribution. METHODS: A modified FTC prodrug (MFTC) was synthesized by palmitoyl chloride esterification. MFTC's chemical structure was evaluated by nuclear magnetic resonance. The created hydrophobic prodrug nanocrystals were encased into a poloxamer surfactant and the pharmacokinetics (PK), biodistribution and antiretroviral activities of the nanoformulation (NMFTC) were assessed. The conversion of MFTC to FTC triphosphates was evaluated. RESULTS: MFTC coated with poloxamer formed stable nanocrystals (NMFTC). NMFTC demonstrated an average particle size, polydispersity index and zeta potential of 350 nm, 0.24 and -20 mV, respectively. Drug encapsulation efficiency was 90%. NMFTC was readily taken up by human monocyte-derived macrophages yielding readily detected intracellular FTC triphosphates and an extended PK profile. CONCLUSION: NMFTC shows improved antiretroviral activities over native FTC. This is coordinate with its extended apparent half-life. The work represents an incremental advance in the development of a long-acting FTC formulation.

Creation of a long-acting rilpivirine prodrug nanoformulation.

Antiretroviral therapy requires lifelong daily dosing to attain viral suppression, restore immune function, and improve quality of life. As a treatment alternative, long-acting (LA) antiretrovirals can sustain therapeutic drug concentrations in blood for prolonged time periods. The success of recent clinical trials for LA parenteral cabotegravir and rilpivirine highlight the emergence of these new therapeutic options. Further optimization can improve dosing frequency, lower injection volumes, and facilitate drug-tissue distributions. To this end, we report the synthesis of a library of RPV prodrugs designed to sustain drug plasma concentrations and improved tissue biodistribution. The lead prodrug M3RPV was nanoformulated into the stable LA injectable NM3RPV. NM3RPV treatment led to RPV plasma concentrations above the protein-adjusted 90% inhibitory concentration for 25 weeks with substantial tissue depots after a single intramuscular injection in BALB/cJ mice. NM3RPV elicited 13- and 26-fold increases in the RPV apparent half-life and mean residence time compared to native drug formulation. Taken together, proof-of-concept is provided that nanoformulated RPV prodrugs can extend the apparent drug half-life and improve tissue biodistribution. These results warrant further development for human use.

Biodegradable polyanhydride-based nanomedicines for blood to brain drug delivery.

An urgent need to deliver therapeutics across the blood-brain barrier (BBB) underlies a paucity of effective therapies currently available for treatment of degenerative, infectious, traumatic, chemical, and metabolic disorders of the nervous system. With an eye toward achieving this goal, an in vitro BBB model was employed to simulate biodegradable polyanhydride nanoparticle-based drug delivery to the brain. Using a combination of confocal microscopy, flow cytometry, and high performance liquid chromatography, we examined the potential of polyanhydride nanoparticles containing the anti-oxidant, mito-apocynin, to be internalized and then transferred from monocytes to human brain microvascular endothelial cells. The efficacy of this nanoparticle-based delivery platform was demonstrated by neuronal protection against oxidative stress. Taken together, this polyanhydride nanoparticle-based delivery system holds promise for enhancing neuroprotection by facilitating drug transport across the BBB. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2881-2890, 2018.

Bioimaging predictors of rilpivirine biodistribution and antiretroviral activities.

Antiretroviral therapy (ART) has changed the outcome of human immunodeficiency virus type one (HIV-1) infection from certain death to a life free of disease co-morbidities. However, infected people must remain on life-long daily ART. ART reduces but fails to eliminate the viral reservoir. In order to improve upon current treatment regimens, our laboratory created long acting slow effective release (LASER) ART nanoformulated prodrugs from native medicines. LASER ART enables antiretroviral drugs (ARVs) to better reach target sites of HIV-1 infection while, at the same time, improve ART's half-life and potency. However, novel ARV design has been slowed by prolonged pharmacokinetic testing requirements. To such ends, tri-modal theranostic nanoparticles were created with single-photon emission computed tomography (SPECT/CT), magnetic resonance imaging (MRI) and fluorescence capabilities to predict LASER ART biodistribution. The created theranostic ARV probes were then employed to monitor drug tissue distribution and potency. Intrinsically 111Indium (111In) radiolabeled, europium doped cobalt-ferrite particles and rilpivirine were encased in a polycaprolactone core surrounded by a lipid shell (111InEuCF-RPV). Particle cell and tissue distribution, and antiretroviral activities were sustained in macrophage tissue depots. 111InEuCF-PCL/RPV particles injected into mice demonstrated co-registration of MRI and SPECT/CT tissue signals with RPV and cobalt. Cell and animal particle biodistribution paralleled ARV activities. We posit that particle selection can predict RPV distribution and potency facilitated by multifunctional theranostic nanoparticles.

Antiretroviral Drug Metabolism in Humanized PXR-CAR-CYP3A-NOG Mice.

Antiretroviral drug (ARV) metabolism is linked largely to hepatic cytochrome P450 activity. One ARV drug class known to be metabolized by intestinal and hepatic CYP3A are the protease inhibitors (PIs). Plasma drug concentrations are boosted by CYP3A inhibitors such as cobisistat and ritonavir (RTV). Studies of such drug-drug interactions are limited since the enzyme pathways are human specific. While immune-deficient mice reconstituted with human cells are an excellent model to study ARVs during human immunodeficiency virus type 1 (HIV-1) infection, they cannot reflect human drug metabolism. Thus, we created a mouse strain with the human pregnane X receptor, constitutive androstane receptor, and CYP3A4/7 genes on a NOD.Cg-Prkdcscid Il2rgtm1Sug /JicTac background (hCYP3A-NOG) and used them to evaluate the impact of human CYP3A metabolism on ARV pharmacokinetics. In proof-of-concept studies we used nanoformulated atazanavir (nanoATV) with or without RTV. NOG and hCYP3A-NOG mice were treated weekly with 50 mg/kg nanoATV alone or boosted with nanoformulated ritonavir (nanoATV/r). Plasma was collected weekly and liver was collected at 28 days post-treatment. Plasma and liver atazanavir (ATV) concentrations in nanoATV/r-treated hCYP3A-NOG mice were 2- to 4-fold higher than in replicate NOG mice. RTV enhanced plasma and liver ATV concentrations 3-fold in hCYP3A-NOG mice and 1.7-fold in NOG mice. The results indicate that human CYP3A-mediated drug metabolism is reduced compared with mouse and that RTV differentially affects human gene activity. These differences can affect responses to PIs in humanized mouse models of HIV-1 infection. Importantly, hCYP3A-NOG mice reconstituted with human immune cells can be used for bench-to-bedside translation.

Multimodal Theranostic Nanoformulations Permit Magnetic Resonance Bioimaging of Antiretroviral Drug Particle Tissue-Cell Biodistribution.

RATIONALE: Long-acting slow effective release antiretroviral therapy (LASER ART) was developed to improve patient regimen adherence, prevent new infections, and facilitate drug delivery to human immunodeficiency virus cell and tissue reservoirs. In an effort to facilitate LASER ART development, "multimodal imaging theranostic nanoprobes" were created. These allow combined bioimaging, drug pharmacokinetics and tissue biodistribution tests in animal models. METHODS: Europium (Eu3+)- doped cobalt ferrite (CF) dolutegravir (DTG)- loaded (EuCF-DTG) nanoparticles were synthesized then fully characterized based on their size, shape and stability. These were then used as platforms for nanoformulated drug biodistribution. RESULTS: Folic acid (FA) decoration of EuCF-DTG (FA-EuCF-DTG) nanoparticles facilitated macrophage targeting and sped drug entry across cell barriers. Macrophage uptake was higher for FA-EuCF-DTG than EuCF-DTG nanoparticles with relaxivities of r2 = 546 mM-1s-1 and r2 = 564 mM-1s-1 in saline, and r2 = 850 mM-1s-1 and r2 = 876 mM-1s-1 in cells, respectively. The values were ten or more times higher than what was observed for ultrasmall superparamagnetic iron oxide particles (r2 = 31.15 mM-1s-1 in saline) using identical iron concentrations. Drug particles were detected in macrophage Rab compartments by dual fluorescence labeling. Replicate particles elicited sustained antiretroviral responses. After parenteral injection of FA-EuCF-DTG and EuCF-DTG into rats and rhesus macaques, drug, iron and cobalt levels, measured by LC-MS/MS, magnetic resonance imaging, and ICP-MS were coordinate. CONCLUSION: We posit that these theranostic nanoprobes can assess LASER ART drug delivery and be used as part of a precision nanomedicine therapeutic strategy.

Development of europium doped core-shell silica cobalt ferrite functionalized nanoparticles for magnetic resonance imaging.

The size, shape and chemical composition of europium (Eu3+) cobalt ferrite (CFEu) nanoparticles were optimized for use as a "multimodal imaging nanoprobe" for combined fluorescence and magnetic resonance bioimaging. Doping Eu3+ ions into a CF structure imparts unique bioimaging and magnetic properties to the nanostructure that can be used for real-time screening of targeted nanoformulations for tissue biodistribution assessment. The CFEu nanoparticles (size ∼7.2nm) were prepared by solvothermal techniques and encapsulated into poloxamer 407-coated mesoporous silica (Si-P407) to form superparamagnetic monodisperse Si-CFEu nanoparticles with a size of ∼140nm. Folic acid (FA) nanoparticle decoration (FA-Si-CFEu, size ∼140nm) facilitated monocyte-derived macrophage (MDM) targeting. FA-Si-CFEu MDM uptake and retention was higher than seen with Si-CFEu nanoparticles. The transverse relaxivity of both Si-CFEu and FA-Si-CFEu particles were r2=433.42mM-1s-1 and r2=419.52mM-1s-1 (in saline) and r2=736.57mM-1s-1 and r2=814.41mM-1s-1 (in MDM), respectively. The results were greater than a log order-of-magnitude than what was observed at replicate iron concentrations for ultrasmall superparamagnetic iron oxide (USPIO) particles (r2=31.15mM-1s-1 in saline) and paralleled data sets obtained for T2 magnetic resonance imaging. We now provide a developmental opportunity to employ these novel particles for theranostic drug distribution and efficacy evaluations. STATEMENT OF SIGNIFICANCE: A novel europium (Eu3+) doped cobalt ferrite (Si-CFEu) nanoparticle was produced for use as a bioimaging probe. Its notable multifunctional, fluorescence and imaging properties, allows rapid screening of future drug biodistribution. Decoration of the Si-CFEu particles with folic acid increased its sensitivity and specificity for magnetic resonance imaging over a more conventional ultrasmall superparamagnetic iron oxide particles. The future use of these particles in theranostic tests will serve as a platform for designing improved drug delivery strategies to combat inflammatory and infectious diseases.

The mixed lineage kinase-3 inhibitor URMC-099 improves therapeutic outcomes for long-acting antiretroviral therapy.

During studies to extend the half-life of crystalline nanoformulated antiretroviral therapy (nanoART) the mixed lineage kinase-3 inhibitor URMC-099, developed as an adjunctive neuroprotective agent was shown to facilitate antiviral responses. Long-acting ritonavir-boosted atazanavir (nanoATV/r) nanoformulations co-administered with URMC-099 reduced viral load and the numbers of HIV-1 infected CD4+ T-cells in lymphoid tissues more than either drug alone in infected humanized NOD/SCID/IL2Rγc-/- mice. The drug effects were associated with sustained ART depots. Proteomics analyses demonstrated that the antiretroviral responses were linked to affected phagolysosomal storage pathways leading to sequestration of nanoATV/r in Rab-associated recycling and late endosomes; sites associated with viral maturation. URMC-099 administered with nanoATV induced a dose-dependent reduction in HIV-1p24 and reverse transcriptase activity. This drug combination offers a unique chemical marriage for cell-based viral clearance. From the Clinical Editor: Although successful in combating HIV-1 infection, the next improvement in antiretroviral therapy (nanoART) would be to devise long acting therapy, such as intra-cellular depots. In this report, the authors described the use of nanoformulated antiretroviral therapy given together with the mixed lineage kinase-3 inhibitor URMC-099, and showed that this combination not only prolonged drug half-life, but also had better efficacy. The findings are hoped to be translated into the clinical setting in the future.

Cellular Responses and Tissue Depots for Nanoformulated Antiretroviral Therapy.

Long-acting nanoformulated antiretroviral therapy (nanoART) induces a range of innate immune migratory, phagocytic and secretory cell functions that perpetuate drug depots. While recycling endosomes serve as the macrophage subcellular depots, little is known of the dynamics of nanoART-cell interactions. To this end, we assessed temporal leukocyte responses, drug uptake and distribution following both intraperitoneal and intramuscular injection of nanoformulated atazanavir (nanoATV). Local inflammatory responses heralded drug distribution to peritoneal cell populations, regional lymph nodes, spleen and liver. This proceeded for three days in male Balb/c mice. NanoATV-induced changes in myeloid populations were assessed by fluorescence-activated cell sorting (FACS) with CD45, CD3, CD11b, F4/80, and GR-1 antibodies. The localization of nanoATV within leukocyte cell subsets was determined by confocal microscopy. Combined FACS and ultra-performance liquid chromatography tandem mass-spectrometry assays determined nanoATV carriages by cell-based vehicles. A robust granulocyte, but not peritoneal macrophage nanoATV response paralleled zymosan A treatment. ATV levels were highest at sites of injection in peritoneal or muscle macrophages, dependent on the injection site. The spleen and liver served as nanoATV tissue depots while drug levels in lymph nodes were higher than those recorded in plasma. Dual polymer and cell labeling demonstrated a nearly exclusive drug reservoir in macrophages within the liver and spleen. Overall, nanoART induces innate immune responses coincident with rapid tissue macrophage distribution. Taken together, these works provide avenues for therapeutic development designed towards chemical eradication of human immunodeficiency viral infection.

Magnetic resonance imaging of folic acid-coated magnetite nanoparticles reflects tissue biodistribution of long-acting antiretroviral therapy.

Regimen adherence, systemic toxicities, and limited drug penetrance to viral reservoirs are obstacles limiting the effectiveness of antiretroviral therapy (ART). Our laboratory's development of the monocyte-macrophage-targeted long-acting nanoformulated ART (nanoART) carriage provides a novel opportunity to simplify drug-dosing regimens. Progress has nonetheless been slowed by cumbersome, but required, pharmacokinetic (PK), pharmacodynamics, and biodistribution testing. To this end, we developed a small magnetite ART (SMART) nanoparticle platform to assess antiretroviral drug tissue biodistribution and PK using magnetic resonance imaging (MRI) scans. Herein, we have taken this technique a significant step further by determining nanoART PK with folic acid (FA) decorated magnetite (ultrasmall superparamagnetic iron oxide [USPIO]) particles and by using SMART particles. FA nanoparticles enhanced the entry and particle retention to the reticuloendothelial system over nondecorated polymers after systemic administration into mice. These data were seen by MRI testing and validated by comparison with SMART particles and direct evaluation of tissue drug levels after nanoART. The development of alendronate (ALN)-coated magnetite thus serves as a rapid initial screen for the ability of targeting ligands to enhance nanoparticle-antiretroviral drug biodistribution, underscoring the value of decorated magnetite particles as a theranostic tool for improved drug delivery.

Enabling nanomaterial, nanofabrication and cellular technologies for nanoneuromedicines.

Nanoparticulate delivery systems represent an area of particular promise for nanoneuromedicines. They possess significant potential for desperately needed therapies designed to combat a range of disorders associated with aging. As such, the field was selected as the focus for the 2014 meeting of the American Society for Nanomedicine. Regenerative, protective, immune modulatory, anti-microbial and anti-inflammatory products, or imaging agents are readily encapsulated in or conjugated to nanoparticles and as such facilitate the delivery of drug payloads to specific action sites across the blood-brain barrier. Diagnostic imaging serves to precisely monitor disease onset and progression while neural stem cell replacement can regenerate damaged tissue through control of stem cell fates. These, taken together, can improve disease burden and limit systemic toxicities. Such enabling technologies serve to protect the nervous system against a broad range of degenerative, traumatic, metabolic, infectious and immune disorders. From the clinical editor: Nanoneuromedicine is a branch of nanomedicine that specifically looks at the nervous system. In the clinical setting, a fundamental hurdle in nervous system disorders is due to an inherent inability of nerve cells to regenerate after damage. Nanotechnology can offer new approaches to overcome these challenges. This review describes recent developments in nanomedicine delivery systems that would affect stem cell repair and regeneration in the nervous system.

Pharmacodynamics of long-acting folic acid-receptor targeted ritonavir-boosted atazanavir nanoformulations.

Long-acting nanoformulated antiretroviral therapy (nanoART) that targets monocyte-macrophages could improve the drug's half-life and protein-binding capacities while facilitating cell and tissue depots. To this end, ART nanoparticles that target the folic acid (FA) receptor and permit cell-based drug depots were examined using pharmacokinetic and pharmacodynamic (PD) tests. FA receptor-targeted poloxamer 407 nanocrystals, containing ritonavir-boosted atazanavir (ATV/r), significantly increased drug bioavailability and PD by five and 100 times, respectively. Drug particles administered to human peripheral blood lymphocyte reconstituted NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ mice and infected with HIV-1ADA led to ATV/r drug concentrations that paralleled FA receptor beta staining in both the macrophage-rich parafollicular areas of spleen and lymph nodes. Drug levels were higher in these tissues than what could be achieved by either native drug or untargeted nanoART particles. The data also mirrored potent reductions in viral loads, tissue viral RNA and numbers of HIV-1p24+ cells in infected and treated animals. We conclude that FA-P407 coating of ART nanoparticles readily facilitates drug carriage and antiretroviral responses.

Development of HIV reservoir targeted long acting nanoformulated antiretroviral therapies.

Human immunodeficiency virus (HIV) infection commonly results in a myriad of comorbid conditions secondary to immune deficiency. Infection also affects broad organ system function. Although current antiretroviral therapy (ART) reduces disease morbidity and mortality through effective control of peripheral viral load, restricted infection in HIV reservoirs including gut, lymphoid and central nervous system tissues, is not eliminated. What underlies these events is, in part, poor ART penetrance into each organ across tissue barriers, viral mutation and the longevity of infected cells. We posit that one means to improve these disease outcomes is through nanotechnology. To this end, this review discusses a broad range of cutting-edge nanomedicines and nanomedicine platforms that are or can be used to improve ART delivery. Discussion points include how polymer-drug conjugates, dendrimers, micelles, liposomes, solid lipid nanoparticles and polymeric nanoparticles can be harnessed to best yield cell-based delivery systems. When completely developed, such nanomedicine platforms have the potential to clear reservoirs of viral infection.

Endosomal trafficking of nanoformulated antiretroviral therapy facilitates drug particle carriage and HIV clearance.

UNLABELLED: 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. IMPORTANCE: 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.