Figure 2.

Morphology, in vitro activity, and tissue biodistribution of nanoformulated antiretroviral therapy (nanoART). Serum drug and tissue levels in mice treated with 2 weekly injections of different doses of nanoART (atazanavir [ATV] and ritonavir [RTV]). A, Scanning electron micrographs (×15 000) of nanoformulations of ATV formulated by wet-milling (M3001) or homogenization (H3001), RTV formulated by wet-milling (M2001) or homogenization (H2001), and homogenized efavirenz (EFV) (H4001) on 0.2-µm polycarbonate filter membranes. Bar = 1 μm. B, Selection criteria for formulations used. P188, poloxamer 188; mPEG₂₀₀₀-DSPE, 1,2-distearoyl-phosphatidylethanolamine-methyl-polyethyleneglycol conjugate-2000; PDI, polydispersity index; PK, pharmacokinetics. ^aFormulations were produced by wet-milling (M) or high-pressure homogenization (H). ^bScoring of PDI, in vitro activity (MDM nanoART uptake, 15-day drug retention, drug release, and antiviral activities) and cytotoxicity (alamarBlue reduction and tumor necrosis factor α MDM production were determined as a decade weighted ratio (see Methods). Scoring of PK was determined as a function of the highest serum drug levels 7 days after nanoART administration (250 mg/kg subcutaneously) to BALB/cJ mice. Drug levels of ATV and RTV were determined from serum on days 1, 6, and 14 (C) and tissues on day 14 (D) after 2 weekly subcutaneous injections of combined nanoART (ATV/RTV; M2001 + M3001; 80, 150, or 250 mg/kg each) given to nonreconstituted, noninfected NSG mice on days 0 and 7. Data are expressed as median ± 25th (serum) and 75th (serum and tissues) percentiles for 5 mice per group. Differences were determined by analysis of variance of rank-transformed values and Tukey post hoc analysis. ^†Significantly different from values for other doses at that day or tissue at P ≤ .05.