Nanoparticle-Based ARV Drug Combinations for Synergistic Inhibition of Cell-Free and Cell–Cell HIV Transmission

Abstract

Nanocarrier-based drug delivery systems are playing an emerging role in human immunodeficiency virus (HIV) chemoprophylaxis and treatment due to their ability to alter the pharmacokinetics and improve the therapeutic index of various antiretroviral (ARV) drug compounds used alone and in combination. Although several nanocarriers have been described for combination delivery of ARV drugs, measurement of drug-drug activities facilitated by the use of these nanotechnology platforms has not been fully investigated for topical prevention. Here, we show that physicochemically diverse ARV drugs can be encapsulated within polymeric nanoparticles to deliver multidrug combinations that provide potent HIV chemoprophylaxis in relevant models of cell-free, cell-cell, and mucosal tissue infection. In contrast to existing approaches that coformulate ARV drug combinations together in a single nanocarrier, we prepared single-drug-loaded nanoparticles that were subsequently combined upon administration. ARV drug-nanoparticles were prepared using emulsion-solvent evaporation techniques to incorporate maraviroc (MVC), etravirine (ETR), and raltegravir (RAL) into poly(lactic-co-glycolic acid) (PLGA) nanoparticles. We compared the antiviral potency of the free and formulated drug combinations for all pairwise and triple drug combinations against both cell-free and cell-associated HIV-1 infection in vitro. The efficacy of ARV-drug nanoparticle combinations was also assessed in a macaque cervicovaginal explant model using a chimeric simian-human immunodeficiency virus (SHIV) containing the reverse transcriptase (RT) of HIV-1. We observed that our ARV-NPs maintained potent HIV inhibition and were more effective when used in combinations. In particular, ARV-NP combinations involving ETR-NP exhibited significantly higher antiviral potency and dose-reduction against both cell-free and cell-associated HIV-1 BaL infection in vitro. Furthermore, ARV-NP combinations that showed large dose-reduction were identified to be synergistic, whereas the equivalent free-drug combinations were observed to be strictly additive. Higher intracellular drug concentration was measured for cells dosed with the triple ARV-NP combination compared to the equivalent unformulated drugs. Finally, as a first step toward evaluating challenge studies in animal models, we also show that our ARV-NP combinations inhibit RT-SHIV virus propagation in macaque cervicovaginal tissue and block virus transmission by migratory cells emigrating from the tissue. Our results demonstrate that ARV-NP combinations control HIV-1 transmission more efficiently than free-drug combinations. These studies provide a rationale to better understand the role of nanocarrier systems in facilitating multidrug effects in relevant cells and tissues associated with HIV infection.

From in silico hit to long-acting late-stage preclinical candidate to combat HIV-1 infection

“…Characterization of compound I-NPs showed that it was encapsulated in PLGA NPs with the appropriate particle size (370 ± 9.2 nm) and zeta potential (−28 ± 0.1). The negative zeta potential suggests that compound I-NP could have prolonged circulation time in vivo by escaping uptake in cells and tissues (48,49). A prolonged circulation time for compound I-NP was confirmed by preliminary pharmacokinetic studies.…”

Harnessing nanostructured systems for improved treatment and prevention of HIV disease

“…The goal of such microbicides is local delivery of ARVs to the site of exposure to prevent the acquisition of HIV. The application of nanostructured systems to microbicide formulation can result in prolonged ARV retention at the site of action for sustained transmission protection, increased cellular uptake, protection of microbicide agents from inactivation by the vaginal microenvironment, and improved antiviral activity of encapsulated ARVs . Many microbicides are ARV encapsulating, insertable solids or hydrogels made from electrospun polymer fibers, dendrimers, or other polymer NPs.…”

“…ARVs. [116][117][118] Many microbicides are ARV encapsulating, insertable solids or hydrogels made from electrospun polymer fibers, dendrimers, or other polymer NPs. While hydrogels have traditionally been used for local treatment or prevention, there has been recent success with the systemic release of locally delivered hydrogels.…”

Nanoparticle Encapsulation for Antiretroviral Pre-Exposure Prophylaxis

“…To examine the potential synergistic anti-HIV activity of combination ART in nano-particle fabrications, encapsulation of single, dual or triple drug combinations of the entry inhibitor maraviroc, (MVC), the NNRTI etravirine (ETR), and the ISTI raltegravir (RAL) into PLGA-NPs were developed [ 36 ] ( Table 1 ). Drugs were encapsulated in PLGA using an emulsion-solvent evaporation protocol ( Table 1 ).…”

“…Drug synergy was only observed when ETR was paired with RAL or MVC and encapsulated into a polymeric nano-formulation. Interestingly, triple NP treatments did not show any increased potency over the double drug combinations (IC 50 :0.40nM) [ 36 ] . However, triple combination NP treatments were associated with higher intracellular concentrations than free-drug triple combination as measured by LC-MS/MS.…”