Cellulose Acetate Phthalate and Antiretroviral Nanoparticle Fabrications for HIV Pre-Exposure Prophylaxis

Abstract

To adequately reduce new HIV infections, development of highly effective pre-exposure prophylaxis (PrEP) against HIV infection in women is necessary. Cellulose acetate phthalate (CAP) is a pH sensitive polymer with HIV-1 entry inhibitory properties. Dolutegravir (DTG) is an integrase strand transfer inhibitor with potent antiretroviral activity. DTG delivered in combination with CAP may significantly improve current PrEP against HIV. In the present study the development of DTG-loaded CAP nanoparticles incorporated in thermosensitive (TMS) gel at vaginal pH 4.2 and seminal fluid pH 7.4 is presented as proof-of-concept for improved PrEP. Water–oil–in–water homogenization was used to fabricate DTG-loaded CAP nanoparticles (DTG–CAP–NPs). Size, polydispersity, and morphological analyses illustrate that DTG–CAP–NPs were smooth and spherical, ≤200 nm in size, and monodispersed with a polydispersity index PDI ≤ 0.2. The drug encapsulation (EE%) and release profile of DTG–CAP–NPs was determined by HPLC analysis. The EE% of DTG in DTG–CAP–NPs was evaluated to be ∼70%. The thermal sensitivity of the TMS gel was optimized and the pH dependency was evaluated by rheological analysis. DTG release studies in TMS gel revealed that DTG–CAP–NPs were stable in TMS gel at pH 4.2 while DTG–CAP–NPs in TMS gel at pH 7.4 rapidly release DTG (≥80% release within 1 h). Cytotoxicity studies using vaginal cell lines revealed that DTG–CAP–NPs were relatively non-cytotoxic at concentration <1 μg/mL. Confocal microscopic studies illustrate that ≥98% cells retained DTG–CAP–NPs intracellularly over seven days. Antiretroviral drug loaded nanocellulose fabrications in TMS gel delivered intravaginally may enhance both microbicidal and antiretroviral drug efficacy and may present a novel option for female PrEP against HIV.

Targeted immuno-antiretroviral HIV therapeutic approach to provide dual protection and boosts cellular immunity: A proof-of-concept study

“…The combination or dual protection of xfR5-D+T NP demonstrates more rigorous protection compared to only blocking CCR5 receptors on T-cells by multimeric CCR5 T-cell blocking, i.e., 5.5 times higher; and ARV induced HIV protection by treating with D+T NP alone, i.e., 3.5 times compared to ARV by D+T NP alone. Further, it is well established (9, 10, 30, 31) and our study also reflects (Table 4), that reduced cytotoxic effect and the increased protection efficacy against HIV, widens the therapeutic index of xfR5-D+T NPs against HIV-1 virus. The enhanced high therapeutic index, therefore, advocates the potency of xfR5-D+T NPs as an advanced HIV therapeutic.…”

“…The nanoencapsulation of ARV drugs has known to reduce the toxicity of naïve drugs (9, 10, 30, 31). A comparative cytotoxicity study performed on TZM-bl cells and primary peripheral blood mononuclear cells (PBMCs) (Table 4).…”

“…The % drug entrapment efficiency (%EE) of DTG and TAF in D+T NPs and xfR5-D+T NPs were evaluated by high-performance liquid chromatography (HPLC) instrument by following published methodology (30, 31, 60). Briefly, 1 mg of D+T NPs dissociated in 50 μL DMSO and mobile phase (25mM KH 2 PO 4 45%: ACN 55%) added to get 10% DMSO final concentration in the injection volume (20 μL).…”

“…The intracellular uptake and retention kinetics of D+T NPs and D+T solution were evaluated by LC-MS/MS analysis following a standardized method (9, 30, 62). Briefly, TZM-bl cells (10 4 cells/well) seeded in the 24-well plate with the complete HiDMEM medium.…”

Targeted Immuno-Antiretroviral HIV Therapeutic Approach to Provide Dual Protection and Boosts Cellular Immunity: A Proof-of-Concept Study

“…Besides, the presence of amide bond, O-H stretching (3000-3500 cm-1) conferred xfR5 mAbs are surface decorated with an ample amount of free surface on NP with predominant PEG-PLGA composition. It is known that the onset of steric crowding compromises the binding avidity during multimeric interaction (38).…”