Fig. 4.

Enhancement in tumor apoptotic response by TUNEL staining. Tumor TUNEL staining to indicate enhancement in apoptotic activity in SKOV3_TR and MCF7_TR tumor sections, harvested at day 28 following a single-dose intravenous treatment with 20 mg/kg paclitaxel (PTX) and/or 80 mg/kg C6-ceramide (CER) administered as free drug or within polymer-blend nanoparticles (NP). Control indicates no treatment. Tumors are sectioned in 12-μm sections and stained for exposed dUTP nick-end labels indicative of apoptotic activity in the tumor cells. Regions of dark purple staining indicate TUNEL-positive regions in the tumor section. Images are at ×200 magnification