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theses

Curing HIV-1 infection has remained elusive due to low and fluctuating drug levels, arising from poor absorption, viral reservoirs and sanctuary sites, toxicity and patient non-adherence. The theme of the current study is to investigate the value of combining AIDS drugs and modifiers of cellular uptake into macromolecular nanocarriers having novel pharmacological properties for improving current anti-HIV therapy. Nanopharmaceuticals were prepared from different combinations of saquinavir (SQV), R.I.CK-Tat9 and the polymeric nanocarrier polyethylene glycol. Anti-HIV activities were measured in MT-2 cells while parallel studies were performed in uninfected cells to determine cellular toxicity. Flow cytometry and confocal microscopy studies suggested that variations in intracellular uptake and intracellular localization, as well as synergistic inhibitory effects of SQV and Tat peptides, contributed to the unexpected and substantial differences in antiviral activity. Our results demonstrate that highly potent multi-drug nanopharmaceuticals with low non-specific toxicity can be produced by combining moieties with anti-HIV agents for different targets onto macromolecules having improved delivery properties.
The present study also addressed the issue of insufficient drug exposure of viral reservoirs in macrophages. Macrophages are a key target and primary cellular reservoir for HIV, and are believed to be responsible for the viral rebound effect observed upon the discontinuation of therapy. In this study, multiple copies of N-formyl-Met-Leu-Phe (fMLF), a known chemo-attractant for macrophages, were conjugated to multifunctional nanocarrier derived from commercially available or novel peptide-based PEGs. The results of uptake studies indicated that appending only two copies of fMLF to the nanocarrier is sufficient for optimal binding and the optimal size of the nanocarrier was about 20 kDa. Further pharmacokinetics and biodistribution studies demonstrated that the attachment of fMLF increased accumulation of PEG nanocarriers in major macrophage-residing tissues such as liver, kidneys and spleen. Taken together, these results demonstrated the feasibility of using macrophage-targeted nanocarriers for enhancing drug uptake in human macrophage-like cells in vitro or macrophages residing in tissues in vivo. These results indicate great promise for enhancing targeted drug delivery to HIV-infected macrophages, which may eventually improve current anti-HIV therapy by improving therapeutic efficacy, minimizing systemic toxicity and simplifying administration regimens.

Ph.D.

Includes bibliographical references (p. 167-189).

http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.13849

ETD_133

doi:10.7282/T3M32W7C

ETD doctoral

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