Figure 4.

(A) IC₅₀ of PC3M (prostate stem cell antigen-positive) cells after 24, 48, and 72 hours of incubation with docetaxel, PLGA/docetaxel, scAb-PLGA/docetaxel, PLGA-SPIO/docetaxel, or scAb-PLGA-SPIO/docetaxel. The Cell Counting Kit-8 assay was used to evaluate cytotoxicity. The data are expressed as the mean ± standard error of the mean (n = 3). ^*,#P < 0.05. (B) Cellular uptake in PC3M cells. PC3M cells were incubated with scAb-PLGA-SPIO/docetaxel or PLGA-SPIO/docetaxel for 2 hours, and intracellular docetaxel was measured by high-pressure liquid chromatography. To determine the competitive inhibition of uptake, excess free prostate stem cell antigen monoclonal antibodies were added to the medium prior to incubation with scAb-PLGA-SPIO/docetaxel. The results are shown as the mean ± standard error of the mean (n = 4). ^*P < 0.05. (C) Binding of targeted and nontargeted nanoparticles was investigated using a flow cytometer assay. PC3M and HT29 cells were incubated with void nanoparticles (control), PLGA-SPIO/coumarin (scAb-free nanoparticles), and scAb-PLGA-SPIO/coumarin (scAb nanoparticles) for 30 minutes at 37°C, respectively. Thereafter, the cells were analyzed by flow cytometry. (D) Mean fluorescence intensity of PC3M and HT29 cells in Figure 4C. The results are shown as the mean ± standard error of the mean (n = 3). ^*P < 0.05.

Abbreviations: Dtxl, docetaxel; PLGA, poly(D,L-lactic-co-glycolic acid); SPIO, superparamagnetic iron oxide; NPs, nanoparticles.