Fig 4. Treatment of J774 macrophages infected with L. amazonensis.

At first, macrophage viability under drug and formulation exposure was determined according to methodology; average results and standard deviation of sextuplicates of each treatment are reported above the 100% line of the graph. Treatments that resulted in cell viability below 70% were considered cytotoxic. Then, treatment of infected macrophages with samples were performed as described in methodology. Controls included infected macrophages without treatment (negative leishmanicidal activity, “control” in the graph) and treatment with amphotericin B (positive leishmanicidal activity). Results from the treatment are represented by bars, which relate to the counting of macrophages, normalized to percentage of viability and separated by infectivity level (legend squares): 1–3 parasites per cell are low infection, 4–6 parasites per cell are medium infection, up to 7 parasites per cell is high infection. Standard deviations of bars correspond to triplicates of each treatment. PBCAnp = control n-butyl cyanoacrylate nanoparticles; PBCAnp-polB nanoparticles loaded with polymyxin B 5 mg/mL.