(W0930-03-17) Functionalized PLGA Nanoparticles Encapsulating Emtricitabine and Bictegravir for Delivery Across the Blood Brain Barrier for the Management of HIV Associated Neurocognitive Disorders (HAND)

Purpose: One of the major complications associated with HIV infection are neurocognitive dysfunctions. These dysfunctions vary in severity ranging from mild to severe impairment of cognitive abilities. The prevalence of these neurocognitive impairments are seen in 39-70% of HIV positive patients. The brain microglia cells are recognized as the primary reservoir for HIV-1, thus making the central nervous system (CNS) a vital source of relapse and re-infection. The blood brain barrier prevents the anti-retroviral drugs to reach the brain and maintain therapeutically relevant concentrations for a prolonged period. This is believed to be the root cause of HIV associated neurocognitive impairment. Therefore, to tackle this problem brain targeted delivery systems are needed which can effectively and efficiently delivery anti-retroviral drugs to the brain parenchyma. To this end, the purpose of our study is to develop Emtricitabine and Bictegravir loaded functionalized poly(lactic-co-glycolic acid) nanoparticles that can provide controlled drug release in the brain and potentially eradicate the viral depot.

Methods: Double emulsion technique was optimized to prepare these nanoparticles. The resulting formulation was characterized for its size, zeta potential and polydispersity index (PDI) using the Zetasizer instrument. The nanoparticles were functionalized with cell penetrating peptide (PLGA-PEG-penetratin) and ligand (PLGA-PEG-mannose). The cell penetrating peptide (FITC-Penetratin-cysteine) was conjugated to PLGA-PEG-mal, the conjugation efficiency was determined by quantifying the FITC using spectrophotometer. The in-vitro release and entrapment efficiency of the nanoparticles were determined through RP/HPLC-UV. The functionalized nanoparticles were also assessed for their cytocompatibility and cellular uptake in bEnd.3 cells and primary glial cells. Hemolytic activity of the functionalized and plain nanoparticles was investigated against rat RBCs. The transporting ability of the formulation was assessed through in-vitro blood brain barrier model.

Results: The optimized dual functionalized dual drug loaded nanoparticles had particle size and zeta potential of 235.14± 14.6 nm and -11.29± 1.84mV, respectively with a PDI of 0.086 ± 0.019. The entrapment and loading of Bictegravir was found to be 86.3 ± 9.7% and 8.7 ± 0.98% respectively, while Emtricitabine had the entrapment and loading of 34.3 ± 4.2 % and 14.4 ± 2.3%, respectively. The nanoparticles displayed controlled release of the two drugs, with 90.3 ± 10.7 % Emtricitabine and 85 ± 4.7 % Bictegravir released in 10 days. The cell viability was above 80% even after 6 and 24 hours of treatment with 40 ug/ml concentration of PLGA nanoparticles. The maximum cellular uptake is seen after 6 hours of treatment. The percent hemolysis seen with these nanoparticles was less than 10 %. The modified nanoparticles showed significantly higher cellular uptake and transport across in vitro blood brain barrier (BBB) model as compared to plain nanoparticles.

Conclusion: Polymeric nanoparticles formulated through double emulsion technique had uniform size distribution. The modification of the nanoparticles with mannose and Penetratin (PEN-MAN-NP) displayed superior cellular uptake and transport across in-vitro BBB barrier model while having good biocompatibility with RBCs, bEND.3 cells and primary glial cells. These results indicate that the functionalized PEN-MAN polymeric nanoparticles can effectively deliver both the drugs across the blood brain barrier to the brain in a controlled release fashion thwart the HIV reservoir and manage HIV associated neurocognitive disorder (HAND).

Acknowledgements: This research was supported by the National Institutes of Health (NIH) Grants RO1 AG051574 and RF1 AG068034


(A) Characterization of the functionalized polymeric nanoparticles for size, PDI and zeta potential. (B) displays the release of the hydrophilic drug Emtricitabine from the nanoparticles over a period of 10 days. (C) displays the release of the hydrophobic drug Bictegravir from the nanoparticles over a period of 10 days. Data represented as mean ± S.D. (n = 6). No significant difference in drug release was noted between formulations at all time points. Figure (D) shows the different functionalized lyophilized nanoparticles.


Cell penetrating peptide reaction and FTIR spectra confirming the conjugation reaction between PLGA-PEG-Mal and FITC-Penetration-cys.


(A) Cellular uptake of different PLGA nanoparticles in bEnd.3 cells at 0.5, 1, 2, 4, 6 and 8 h. Data represented as mean ± S.D. (n = 6). At 6 h, drug concentration in the cells was significantly higher than all the earlier time points when treated with 20%PenMan *, # 20%penman was significantly higher compared to other formulations at 6 h p < 0.05). (B) Fluorescence images of bEND.3 cells after treatment with 10% PenMan NP at 6h. (C) Fluorescence images of bEND.3 cells after treatment with 20% PenMan NP at 6h.