Fig. 6.
Hc7 cellular uptake of Rhod-PE-containing immunoliposomes encapsulating nitroxide. Dishes of Hc7 cells were incubated at 37°C with immunoliposomes containing Rhod-PE and loaded with nitroxide 1. At various times, intracellular nitroxide (a) and Rhod-PE (b) were assayed spectroscopically (n = 3). By 6 h, intracellular nitroxide had increased to ∼750 μM through immunoliposomal endocytosis, as verified by parallel uptake of liposomal Rhod-PE. Beyond 6 h, endocytosis slowed markedly (evidenced by lack of further Rhod-PE accumulation) and intracellular nitroxide signal declined (error bars represent SD; where not seen, the bar was smaller than the symbol). Statistical significance (P < 0.05) is denoted by asterisks and double-daggers. ANOVA values: panel a, F5,17 = 11.49; panel b, F5,17 = 53.79