Novel Arsenic Nanoparticles Are More Effective and Less Toxic than As (III) to Inhibit Extracellular and Intracellular Proliferation of Leishmania donovani

Figure 4

As-NPs blocked intramacrophage proliferation of Leishmania parasites. (a) As-NPs reduced the postinfection proliferation of the parasites inside the macrophages. RAW macrophages were infected with Leishmania promastigotes and incubated for 24 hours at 37^°C. 24-hour postinfected macrophages (panels (A) and (B)) were further incubated without ((C)–(F)) and with ((G)–(J)) As-NPs for another 24 ((C), (D), (G), and (H)) and 48 ((E), (F), (I), and (J)) hours. Phase ((A), (C), (E), (G), and (I)), GFP (green), and DAPI (blue) pictures were taken in fluorescence microscope and the GFP and DAPI images were merged ((B), (D), (F), (H), and (J)). These images only represent one of multiple independent sets. Scale bar indicates 2 μm. (b) Quantitation of the intracellular proliferation of L. donovani promastigotes in 24-hour postinfected macrophages incubated in presence of 2 μM As-NPs for another 24 and 48 hours. Numbers of total macrophage and parasite positive (+) dots within each infected cell were separately determined by manual counting of representative images and presented graphically. The error bars indicate standard deviations for the number of parasite positive dots obtained from three independent experiments. denotes statistically significant values (<0.05).

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