Using rifapentine - hen egg lipoprotein conjugate as macrophage-targeted drug delivery carrier against intracellular Staphylococcus aureus.

Context: Hen egg low-density lipoprotein (heLDL), which is present in large quantities in egg yolk, share a high identity with human apolipoprotein B-100 precursor.

Objective: This study investigated the use of heLDL as a macrophage-targeted drug delivery carrier against intracellular Staphylococcus aureus.

Methods: Rifapentine (RPT) was incorporated into heLDL (RPT-heLDL). Staphylococcus aureus ATCC 29740 and human U937 macrophage were used as intracellular infection models.

Results And Conclusion: The loading efficiency of RPT into the heLDL was 66.10 ± 2.28 μg RPT/mg heLDL. Fluorescence microscopy and oil red O staining results indicated RPT-heLDL can be taken up by U937 macrophages. The cell viability (MTT assay) was increased when the concentration of heLDL was <150 μg/mL. Unloaded heLDL (100 μg/mL) can inhibit the growth of intracellular S. aureus compared with the untreated control group after 18 h incubation. RPT-heLDL (6.6 μg/mL RPT, 100 μg/mL heLDL) eliminated 94% of intracellular S. aureus, whereas the corresponding dose of free RPT (6.6 μg/mL) induced an 87% reduction. The in vitro results of the current study indicated that heLDL might be used as a suitable drug carrier for targeting human macrophages.